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Nagai N. Azimuth Angle Dependence of Polarized Infrared Spectra of Injection-Molded Polyoxymethylene. Appl Spectrosc 2024; 78:197-208. [PMID: 38058162 DOI: 10.1177/00037028231217005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/08/2023]
Abstract
Injection-molded polyoxymethylene (POM) has molecular chains mainly oriented in the injection direction. We investigated the directional dependence of the polarized infrared reflection and attenuated total reflection spectra by rotating the anisotropic POM sample. Because of the strong absorption and large frequency dispersion of the C-O vibration in the main-chain direction, we found phenomena such as shoulder wing generation that resulted from the mixing of optical responses attributed to the vibration in the main chain and that in the direction perpendicular to the main chain. The spectra of the directional dependence can be explained qualitatively because of the anisotropy of the mode with large frequency dispersion.
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Affiliation(s)
- Naoto Nagai
- Graduate School of Science and Technology, Niigata University, Nishi-ku, Niigata, Japan
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2
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Cencini M, Lancione M, Pasquariello R, Peretti L, Pirkl CM, Schulte RF, Buonincontri G, Arduino A, Zilberti L, Biagi L, Tosetti M. Fast high-resolution electric properties tomography using three-dimensional quantitative transient-state imaging-based water fraction estimation. NMR Biomed 2024; 37:e5039. [PMID: 37714527 DOI: 10.1002/nbm.5039] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/04/2023] [Revised: 08/18/2023] [Accepted: 08/28/2023] [Indexed: 09/17/2023]
Abstract
In this study, we aimed to develop a fast and robust high-resolution technique for clinically feasible electrical properties tomography based on water content maps (wEPT) using Quantitative Transient-state Imaging (QTI), a multiparametric transient state-based method that is similar to MR fingerprinting. Compared with the original wEPT implementation based on standard spin-echo acquisition, QTI provides robust electrical properties quantification towards B1 + inhomogeneities and full quantitative relaxometry data. To validate the proposed approach, 3D QTI data of 12 healthy volunteers were acquired on a 1.5 T scanner. QTI-provided T1 maps were used to compute water content maps of the tissues using an empirical relationship based on literature ex-vivo measurements. Assuming that electrical properties are modulated mainly by tissue water content, the water content maps were used to derive electrical conductivity and relative permittivity maps. The proposed technique was compared with a conventional phase-only Helmholtz EPT (HH-EPT) acquisition both within whole white matter, gray matter, and cerebrospinal fluid masks, and within different white and gray matter subregions. In addition, QTI-based wEPT was retrospectively applied to four multiple sclerosis adolescent and adult patients, compared with conventional contrast-weighted imaging in terms of lesion delineation, and quantitatively assessed by measuring the variation of electrical properties in lesions. Results obtained with the proposed approach agreed well with theoretical predictions and previous in vivo findings in both white and gray matter. The reconstructed maps showed greater anatomical detail and lower variability compared with standard phase-only HH-EPT. The technique can potentially improve delineation of pathology when compared with conventional contrast-weighted imaging and was able to detect significant variations in lesions with respect to normal-appearing tissues. In conclusion, QTI can reliably measure conductivity and relative permittivity of brain tissues within a short scan time, opening the way to the study of electric properties in clinical settings.
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Affiliation(s)
- Matteo Cencini
- Istituto Nazionale di Fisica Nucleare, Sezione di Pisa, Pisa, Italy
| | | | | | | | | | | | | | | | - Luca Zilberti
- Istituto Nazionale di Ricerca Metrologica (INRiM), Torino, Italy
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3
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Berezhanska M, Godinho DM, Maló P, Conceição RC. Dielectric Characterization of Healthy Human Teeth from 0.5 to 18 GHz with an Open-Ended Coaxial Probe. Sensors (Basel) 2023; 23:1617. [PMID: 36772655 PMCID: PMC9920056 DOI: 10.3390/s23031617] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/12/2022] [Revised: 01/23/2023] [Accepted: 01/28/2023] [Indexed: 06/18/2023]
Abstract
Dental caries is a major oral health issue which compromises oral health, as it is the main cause of oral pain and tooth loss. Early caries detection is essential for effective clinical intervention. However, methods commonly employed for its diagnosis often fail to detect early caries lesions, which motivates the research for more effective diagnostic solutions. In this work, the relative permittivity of healthy permanent teeth, in caries-prone areas, was studied between 0.5 and 18 GHz. The reliability of such measurements is an important first step to, ultimately, evaluate the feasibility of a microwave device for caries detection. The open-ended coaxial probe technique was employed. Its performance showed to be compromised by the poor probe-tooth contact. We proposed a method based on applying coupling media to reduce this limitation. A decrease in the measured relative permittivity variability was observed when the space between the probe tip and tooth surface was filled by coupling media instead of air. The influence of the experimental conditions in the measurement result was found to be less than 5%. Measurements conducted in ex vivo teeth showed that the relative permittivity of the dental crown and root ranges between 10.0-11.0 and 8.0-9.5, respectively.
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Affiliation(s)
- Mariya Berezhanska
- Physics Department, NOVA School of Science and Technology, NOVA University of Lisbon, 2829-516 Caparica, Portugal
| | - Daniela M. Godinho
- Instituto de Biofísica e Engenharia Biomédica, Faculdade de Ciências, Universidade de Lisboa, Campo Grande, 1749-016 Lisbon, Portugal
| | - Paulo Maló
- MALO DENTAL INTERNATIONAL, 1700-029 Lisbon, Portugal
| | - Raquel C. Conceição
- Instituto de Biofísica e Engenharia Biomédica, Faculdade de Ciências, Universidade de Lisboa, Campo Grande, 1749-016 Lisbon, Portugal
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4
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Dehning KJ, Hitzemann M, Gossmann A, Zimmermann S. Split-Ring Resonator Based Sensor for the Detection of Amino Acids in Liquids. Sensors (Basel) 2023; 23:645. [PMID: 36679444 PMCID: PMC9864034 DOI: 10.3390/s23020645] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/14/2022] [Revised: 12/10/2022] [Accepted: 01/04/2023] [Indexed: 06/17/2023]
Abstract
Amino acids belong to the most important compounds for life. They are structural components of proteins and required for growth and maintenance of cells. Essential amino acids cannot be produced by the organism and must be ingested through the nutrition. Therefore, the detection of amino acids is of great interest when analyzing cell culture media and nutrition. In this work, we present a split-ring resonator as a simple but sensitive detector for amino acids. Split-ring resonators are RLC resonant circuits with a split capacitance and thus a resonance frequency that depends on the electromagnetic properties of a liquid sample at the split capacitance. Here, the split capacitance is an interdigital structure for highest sensitivity and covered with a fluidic channel for flow through experiments. First measurements with a vector network analyzer show detection limits in the range from 105 µM for glutamic acid to 1564 µM for isoleucine, depending on the electromagnetic properties of the tested amino acids. With an envelope detector for continuous recording of the resonance frequency, the split-ring resonator can be used in ion chromatography. At a flow rate of 0.5 mL/min, it reaches limits of detection of 485 µM for aspartic acid and 956 µM for lysine.
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5
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Peng Z, Xiao X, Song J, Libanori A, Lee C, Chen K, Gao Y, Fang Y, Wang J, Wang Z, Chen J, Leung MKH. Improving Relative Permittivity and Suppressing Dielectric Loss of Triboelectric Layers for High-Performance Wearable Electricity Generation. ACS Nano 2022; 16:20251-20262. [PMID: 36520674 DOI: 10.1021/acsnano.2c05820] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
High relative permittivity and low dielectric loss are two desired parameters of a triboelectric layer to enhance its mechanical-to-electrical energy conversion efficiency in a triboelectric nanogenerator (TENG). However, the elevated permittivity of the triboelectric layer is always accompanied by increasing dielectric loss, limiting further improvement or even reducing the electrical output. Herein, we report a method for improving the relative permittivity and suppressing the dielectric loss of the triboelectric layer via nanoscale design at the particle-polymer interface. When incorporated with 2 wt % Ag@C, the triboelectric-layer-enhanced TENG (TLE-TENG) presents a 2.6-fold increment in relative permittivity and a 302% current enhancement. An instantaneous peak power density of 1.22 W m-2, an excellent pressure sensitivity of 90.95 V kPa-1, and an optimized sheet resistance (∼0.14 Ω/sq) are attributes of this greatly enhanced device. Such improvements bode well for the implementation of these enhancing strategies to help position TLE-TENGs as pervasive and sustainable power sources and active self-powered sensors in the era of the Internet of Things.
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Affiliation(s)
- Zehua Peng
- Ability R&D Energy Centre, School of Energy and Environment, City University of Hong Kong, Hong Kong 999077, People's Republic of China
| | - Xiao Xiao
- Department of Bioengineering, University of California, Los Angeles, Los Angeles, California 90095, United States
| | - Jianxin Song
- Department of Physics, College of Science, City University of Hong Kong, Hong Kong 999077, People's Republic of China
| | - Alberto Libanori
- Department of Bioengineering, University of California, Los Angeles, Los Angeles, California 90095, United States
| | - Ching Lee
- Institute of Textile and Clothing, The Hong Kong Polytechnic University, Hong Kong, China
| | - Keda Chen
- Ability R&D Energy Centre, School of Energy and Environment, City University of Hong Kong, Hong Kong 999077, People's Republic of China
| | - Yuan Gao
- Institute of Textile and Clothing, The Hong Kong Polytechnic University, Hong Kong, China
| | - Yunsheng Fang
- Department of Bioengineering, University of California, Los Angeles, Los Angeles, California 90095, United States
| | - Juan Wang
- Department of Chemistry, College of Science, City University of Hong Kong, Hong Kong 999077, People's Republic of China
| | - Zuankai Wang
- Department of Mechanical Engineering, College of Engineering, City University of Hong Kong, Hong Kong 999077, People's Republic of China
| | - Jun Chen
- Department of Bioengineering, University of California, Los Angeles, Los Angeles, California 90095, United States
| | - Michael K H Leung
- Ability R&D Energy Centre, School of Energy and Environment, City University of Hong Kong, Hong Kong 999077, People's Republic of China
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6
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Samaddar P, Mishra AK, Gaddam S, Singh M, Modi VK, Gopalakrishnan K, Bayer RL, Igreja Sa IC, Khanal S, Hirsova P, Kostallari E, Dey S, Mitra D, Roy S, Arunachalam SP. Machine Learning-Based Classification of Abnormal Liver Tissues Using Relative Permittivity. Sensors (Basel) 2022; 22:9919. [PMID: 36560303 PMCID: PMC9781624 DOI: 10.3390/s22249919] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/11/2022] [Revised: 12/04/2022] [Accepted: 12/08/2022] [Indexed: 06/17/2023]
Abstract
The search for non-invasive, fast, and low-cost diagnostic tools has gained significant traction among many researchers worldwide. Dielectric properties calculated from microwave signals offer unique insights into biological tissue. Material properties, such as relative permittivity (εr) and conductivity (σ), can vary significantly between healthy and unhealthy tissue types at a given frequency. Understanding this difference in properties is key for identifying the disease state. The frequency-dependent nature of the dielectric measurements results in large datasets, which can be postprocessed using artificial intelligence (AI) methods. In this work, the dielectric properties of liver tissues in three mouse models of liver disease are characterized using dielectric spectroscopy. The measurements are grouped into four categories based on the diets or disease state of the mice, i.e., healthy mice, mice with non-alcoholic steatohepatitis (NASH) induced by choline-deficient high-fat diet, mice with NASH induced by western diet, and mice with liver fibrosis. Multi-class classification machine learning (ML) models are then explored to differentiate the liver tissue groups based on dielectric measurements. The results show that the support vector machine (SVM) model was able to differentiate the tissue groups with an accuracy up to 90%. This technology pipeline, thus, shows great potential for developing the next generation non-invasive diagnostic tools.
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Affiliation(s)
- Poulami Samaddar
- Microwave Engineering and Imaging Laboratory (MEIL), Division of Gastroenterology & Hepatology, Department of Medicine, Mayo Clinic, Rochester, MN 55905, USA
| | - Anup Kumar Mishra
- GIH Artificial Intelligence Laboratory (GAIL), Division of Gastroenterology and Hepatology, Department of Medicine, Mayo Clinic, Rochester, MN 55905, USA
| | - Sunil Gaddam
- Microwave Engineering and Imaging Laboratory (MEIL), Division of Gastroenterology & Hepatology, Department of Medicine, Mayo Clinic, Rochester, MN 55905, USA
| | | | - Vaishnavi K. Modi
- Microwave Engineering and Imaging Laboratory (MEIL), Division of Gastroenterology & Hepatology, Department of Medicine, Mayo Clinic, Rochester, MN 55905, USA
| | - Keerthy Gopalakrishnan
- Microwave Engineering and Imaging Laboratory (MEIL), Division of Gastroenterology & Hepatology, Department of Medicine, Mayo Clinic, Rochester, MN 55905, USA
| | - Rachel L. Bayer
- Gastroenterology Research, Division of Gastroenterology and Hepatology, Mayo Clinic, Rochester, MN 55905, USA
| | - Ivone Cristina Igreja Sa
- Gastroenterology Research, Division of Gastroenterology and Hepatology, Mayo Clinic, Rochester, MN 55905, USA
- Department of Biological and Medical Sciences, Faculty of Pharmacy in Hradec Králové, Charles University, Heyrovskeho 1203, 500 05 Hradec Kralove, Czech Republic
| | - Shalil Khanal
- Gastroenterology Research, Division of Gastroenterology and Hepatology, Mayo Clinic, Rochester, MN 55905, USA
| | - Petra Hirsova
- Gastroenterology Research, Division of Gastroenterology and Hepatology, Mayo Clinic, Rochester, MN 55905, USA
| | - Enis Kostallari
- Gastroenterology Research, Division of Gastroenterology and Hepatology, Mayo Clinic, Rochester, MN 55905, USA
| | - Shuvashis Dey
- Microwave Engineering and Imaging Laboratory (MEIL), Division of Gastroenterology & Hepatology, Department of Medicine, Mayo Clinic, Rochester, MN 55905, USA
- Department of Electrical and Computer Engineering, North Dakota State University, Fargo, ND 58105, USA
| | - Dipankar Mitra
- Microwave Engineering and Imaging Laboratory (MEIL), Division of Gastroenterology & Hepatology, Department of Medicine, Mayo Clinic, Rochester, MN 55905, USA
- Department of Computer Science, University of Wisconsin, La Crosse, WI 54601, USA
| | - Sayan Roy
- Microwave Engineering and Imaging Laboratory (MEIL), Division of Gastroenterology & Hepatology, Department of Medicine, Mayo Clinic, Rochester, MN 55905, USA
- Department of Electrical Engineering and Computer Science, South Dakota Mines, Rapid City, SD 57701, USA
| | - Shivaram P. Arunachalam
- Microwave Engineering and Imaging Laboratory (MEIL), Division of Gastroenterology & Hepatology, Department of Medicine, Mayo Clinic, Rochester, MN 55905, USA
- GIH Artificial Intelligence Laboratory (GAIL), Division of Gastroenterology and Hepatology, Department of Medicine, Mayo Clinic, Rochester, MN 55905, USA
- Department of Radiology, Mayo Clinic, Rochester, MN 55905, USA
- Department of Medicine, Mayo Clinic, Rochester, MN 55905, USA
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7
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Luo H, Wang F, Guo R, Zhang D, He G, Chen S, Wang Q. Progress on Polymer Dielectrics for Electrostatic Capacitors Application. Adv Sci (Weinh) 2022; 9:e2202438. [PMID: 35981884 PMCID: PMC9561874 DOI: 10.1002/advs.202202438] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/03/2022] [Revised: 07/15/2022] [Indexed: 06/15/2023]
Abstract
Polymer dielectrics are attracting increasing attention for electrical energy storage owing to their advantages of mechanical flexibility, corrosion resistance, facile processability, light weight, great reliability, and high operating voltages. However, the dielectric constants of most dielectric polymers are less than 10, which results in low energy densities and limits their applications in electrostatic capacitors for advanced electronics and electrical power systems. Therefore, intensive efforts have been placed on the development of high-energy-density polymer dielectrics. In this perspective, the most recent results on the all-organic polymer dielectrics are summarized, including molecular structure design, polymer blends, and layered structured polymers. The challenges in the field and suggestions for future research on high-energy-density polymer dielectrics are also presented.
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Affiliation(s)
- Hang Luo
- State Key Laboratory of Powder MetallurgyCentral South UniversityChangshaHunan Province410083China
| | - Fan Wang
- State Key Laboratory of Powder MetallurgyCentral South UniversityChangshaHunan Province410083China
| | - Ru Guo
- State Key Laboratory of Powder MetallurgyCentral South UniversityChangshaHunan Province410083China
| | - Dou Zhang
- State Key Laboratory of Powder MetallurgyCentral South UniversityChangshaHunan Province410083China
| | - Guanghu He
- Key Laboratory of Polymeric Materials and Application Technology of Hunan ProvinceCollege of ChemistryXiangtan UniversityXiangtanHunan Province411105China
| | - Sheng Chen
- Key Laboratory of Polymeric Materials and Application Technology of Hunan ProvinceCollege of ChemistryXiangtan UniversityXiangtanHunan Province411105China
| | - Qing Wang
- Department of Materials Science and EngineeringThe Pennsylvania State UniversityUniversity ParkPA16802USA
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8
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Wang M, Wang Y, Li W, Ding J, Bian C, Wang X, Wang C, Li C, Zhong Z, Yu J. Reflection Characteristics Measurements of Indoor Wireless Link in D-Band. Sensors (Basel) 2022; 22:6908. [PMID: 36146265 PMCID: PMC9502431 DOI: 10.3390/s22186908] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/14/2022] [Revised: 09/07/2022] [Accepted: 09/08/2022] [Indexed: 06/16/2023]
Abstract
For the millimeter wave (mm-Wave) and terahertz (THz) indoor wireless communication system, the reflection channels need to be characterized and modeled. In this paper, the reflection measurements of the parallel polarized wave are carried out under multiple incident angles and five kinds of materials in the D-band (110-170 GHz). A modified reflection model with two parameters estimated by the minimum mean square error (MMSE) criterion is proposed. The results show that the measurements are in good agreement with the proposed model. Furthermore, a set of measured properties is demonstrated and it can be concluded that both the reflection coefficients and relative permittivity gradually decrease, whereas the surface roughness increases slightly with the increasing frequency, indicating a weak frequency dependence. Interestingly, the concrete board with high surface roughness, which means more power loss in a specular direction, has the lowest reflection loss at a certain frequency and incident angle. It implies that the reflection characteristics of indoor building materials are determined not only by surface roughness, but also by many other factors, such as relative permittivity, frequency, and incident angle. Our work suggests that the reflection measurements of indoor D-band wireless links have a prospective application for future indoor wireless communication systems.
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Affiliation(s)
- Mingxu Wang
- Department of Communication Science and Engineering, and the Key Laboratory for Information Science of Electromagnetic Waves (MoE), Fudan University, Shanghai 200433, China
| | - Yanyi Wang
- Department of Communication Science and Engineering, and the Key Laboratory for Information Science of Electromagnetic Waves (MoE), Fudan University, Shanghai 200433, China
| | - Weiping Li
- Department of Communication Science and Engineering, and the Key Laboratory for Information Science of Electromagnetic Waves (MoE), Fudan University, Shanghai 200433, China
| | - Junjie Ding
- Department of Communication Science and Engineering, and the Key Laboratory for Information Science of Electromagnetic Waves (MoE), Fudan University, Shanghai 200433, China
| | - Chengzhen Bian
- Department of Communication Science and Engineering, and the Key Laboratory for Information Science of Electromagnetic Waves (MoE), Fudan University, Shanghai 200433, China
| | - Xinyi Wang
- Department of Communication Science and Engineering, and the Key Laboratory for Information Science of Electromagnetic Waves (MoE), Fudan University, Shanghai 200433, China
| | - Chao Wang
- Wireless Network RAN Research Department, Shanghai Huawei Technologies Co., Ltd., Shanghai 201206, China
| | - Chao Li
- Wireless Network RAN Research Department, Shanghai Huawei Technologies Co., Ltd., Shanghai 201206, China
| | - Zhimeng Zhong
- Wireless Network RAN Research Department, Shanghai Huawei Technologies Co., Ltd., Shanghai 201206, China
| | - Jianjun Yu
- Department of Communication Science and Engineering, and the Key Laboratory for Information Science of Electromagnetic Waves (MoE), Fudan University, Shanghai 200433, China
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9
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Lebsir Y, Boroviks S, Thomaschewski M, Bozhevolnyi SI, Zenin VA. Ultimate Limit for Optical Losses in Gold, Revealed by Quantitative Near-Field Microscopy. Nano Lett 2022; 22:5759-5764. [PMID: 35787133 DOI: 10.1021/acs.nanolett.2c01059] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
We report thorough measurements of surface plasmon polaritons (SPPs) running along nearly perfect air-gold interfaces formed by atomically flat surfaces of chemically synthesized gold monocrystals. By means of amplitude- and phase-resolved near-field microscopy, we obtain their propagation length and effective mode index at visible wavelengths (532, 594, 632.8, 729, and 800 nm). The measured values are compared with the values obtained from the dielectric functions of gold that are reported in literature. Importantly, a reported dielectric function of monocrystalline gold implies ∼1.5 times shorter propagation lengths than those observed in our experiments, whereas a dielectric function reported for properly fabricated polycrystalline gold leads to SPP propagation lengths matching our results. We argue that the SPP propagation lengths measured in our experiments signify the ultimate limit of optical losses in gold, encouraging further comprehensive characterization of optical material properties of pure gold as well as other plasmonic materials.
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Affiliation(s)
- Yonas Lebsir
- Centre for Nano Optics, University of Southern Denmark, 5230 Odense, Denmark
- Institute for Experimental and Applied Physics, Kiel University, 24118 Kiel, Germany
| | - Sergejs Boroviks
- Centre for Nano Optics, University of Southern Denmark, 5230 Odense, Denmark
- Nanophotonics and Metrology Laboratory (NAM), Swiss Federal Institute of Technology in Lausanne (EPFL), 1015 Lausanne, Switzerland
| | | | - Sergey I Bozhevolnyi
- Centre for Nano Optics, University of Southern Denmark, 5230 Odense, Denmark
- Danish Institute for Advanced Study, University of Southern Denmark, 5230 Odense, Denmark
| | - Vladimir A Zenin
- Centre for Nano Optics, University of Southern Denmark, 5230 Odense, Denmark
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10
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Kotb HM, Alshoaibi A, Mazher J, Shaalan NM, Ahmad MM. Colossal Permittivity Characteristics of (Nb, Si) Co-Doped TiO(2) Ceramics. Materials (Basel) 2022; 15. [PMID: 35806826 DOI: 10.3390/ma15134701] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/08/2022] [Revised: 06/24/2022] [Accepted: 07/01/2022] [Indexed: 11/23/2022]
Abstract
(Nb5+, Si4+) co-doped TiO2 (NSTO) ceramics with the compositions (Nb0.5Si0.5)xTi1−xO2, x = 0, 0.025, 0.050 and 0.1 were prepared with a solid-state reaction technique. X-ray diffraction (XRD) patterns and Raman spectra confirmed that the tetragonal rutile is the main phase in all the ceramics. Additionally, XRD revealed the presence of a secondary phase of SiO2 in the co-doped ceramics. Impedance spectroscopy analysis showed two contributions, which correspond to the responses of grain and grain-boundary. All the (Nb, Si) co-doped TiO2 showed improved dielectric performance in the high frequency range (>103 Hz). The sample (Nb0.5Si0.5)0.025Ti0.975O2 showed the best dielectric performance in terms of higher relative permittivity (5.5 × 104) and lower dielectric loss (0.18), at 10 kHz and 300 K, compared to pure TiO2 (1.1 × 103, 0.34). The colossal permittivity of NSTO ceramics is attributed to an internal barrier layer capacitance (IBLC) effect, formed by insulating grain-boundaries and semiconductor grains in the ceramics.
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11
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Amaki Y, Okada H, Nagai N. Structural Analysis of Injection-Molded Polyoxymethylene Treated Below a Melting Point Using Field-Emission Scanning Electron Microscopy and Infrared Spectroscopy. Appl Spectrosc 2022; 76:699-711. [PMID: 35081767 DOI: 10.1177/00037028221078050] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
The heat treatment of an injection-molded polyoxymethylene slightly below the melting point and subsequent isothermal treatment at 130 °C were performed. The polyoxymethylene structure was examined using field-emission scanning electron microscopy and polarization infrared reflection measurements. After the heat treatment, a significant change in the surface morphology was observed, and the reflection spectrum derived from the polariton in the injection direction also changed dramatically. Since the reflection spectrum in the injection direction contains the reflection component of the perpendicular direction and vice versa, the polarization spectra of both directions can be calculated consistently. The mixing ratio of each crossed component and the pure relative permittivity both parallel and perpendicular to the main-chain direction were determined using the oscillator model. The heat treatment reduced the ratio of the perpendicular component and increased the order structure until just before melting. The structural changes characterized by the two techniques, along with Raman spectroscopy and differential scanning calorimetry, are discussed.
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Affiliation(s)
- Yuko Amaki
- Industrial Research Institute of Niigata Prefecture, Niigata, Japan
| | - Hideki Okada
- Industrial Research Institute of Niigata Prefecture, Niigata, Japan
| | - Naoto Nagai
- Industrial Research Institute of Niigata Prefecture, Niigata, Japan
- Graduate School of Science and Technology, 594248Niigata University, Niigata, Japan
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12
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Suchorab Z, Tabiś K, Brzyski P, Szczepaniak Z, Rogala T, Susek W, Łagód G. Comparison of the Moist Material Relative Permittivity Readouts Using the Non-Invasive Reflectometric Sensors and Microwave Antenna. Sensors (Basel) 2022; 22:3622. [PMID: 35632030 DOI: 10.3390/s22103622] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/20/2022] [Revised: 05/04/2022] [Accepted: 05/07/2022] [Indexed: 02/04/2023]
Abstract
The article concerns the issue of non-invasive moisture sensing in building materials. Two techniques that enable evaluating the value of the relative permittivity of the material, being the measure of porous material moisture, have been utilized for the research. The first is the microwave technique that utilizes the non-contact measurement of velocity of microwave radiation across the tested material and the second is the time domain reflectometry (TDR) technique based on the measurement of electromagnetic pulse propagation time along the waveguides, being the elements of sensor design. The tested building material involved samples of red ceramic brick that differed in moisture, ranging between 0% and 14% moisture by weight. The main goal of the research was to present the measuring potential of both techniques for moisture evaluation as well as emphasize the advantages and disadvantages of each method. Within the research, it was stated that both methods provide similar measuring potential, with a slight advantage in favor of a microwave non-contact sensor over surface TDR sensor designs.
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13
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Ahmad MM, Alshoaibi A, Ansari SA, Kayed TS, Khater HA, Kotb HM. Dielectric Properties of Bi 2/3Cu 3Ti 4O 12 Ceramics Prepared by Mechanical Ball Milling and Low Temperature Conventional Sintering. Materials (Basel) 2022; 15:3173. [PMID: 35591505 DOI: 10.3390/ma15093173] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/31/2022] [Revised: 04/25/2022] [Accepted: 04/26/2022] [Indexed: 11/17/2022]
Abstract
In the current study, Bi2/3Cu3Ti4O12 (BCTO) ceramics were prepared by mechanical ball mill of the elemental oxides followed by conventional sintering of the powder without any pre-sintering heat treatments. The sintering temperature was in the range 950-990 °C, which is 100-150 °C lower than the previous conventional sintering studies on BCTO ceramics. All the ceramic samples showed body-centered cubic phase and grain size ≈ 2-6 μm. Sintering temperature in the range 950-975 °C resulted in comparatively lower dielectric loss and lower thermal coefficient of permittivity in the temperature range from -50 to 120 °C. All the BCTO ceramics showed reasonably high relative permittivity. The behavior of BCTO ceramics was correlated with the change in oxygen content in the samples with sintering temperature. This interpretation was supported by the measurements of the energy dispersive x-ray spectroscopy (EDS) elemental analysis and activation energy for conduction and for relaxation in the ceramics.
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Horn BKP. Indoor Localization Using Uncooperative Wi-Fi Access Points. Sensors (Basel) 2022; 22:3091. [PMID: 35459075 PMCID: PMC9026139 DOI: 10.3390/s22083091] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/22/2022] [Revised: 04/13/2022] [Accepted: 04/15/2022] [Indexed: 06/14/2023]
Abstract
Indoor localization using fine time measurement (FTM) round-trip time (RTT) with respect to cooperating Wi-Fi access points (APs) has been shown to work well and provide 1-2 m accuracy in both 2D and 3D applications. This approach depends on APs implementing the IEEE 802.11-2016 (also known as IEEE 802.11mc) Wi-Fi standard ("two-sided" RTT). Unfortunately, the penetration of this Wi-Fi protocol has been slower than anticipated, perhaps because APs tend not to be upgraded as often as other kinds of electronics, in particular in large institutions-where they would be most useful. Recently, Google released Android 12, which also supports an alternative "one-sided" RTT method that will work with legacy APs as well. This method cannot subtract out the "turn-around" time of the signal, and so, produces distance estimates that have much larger offsets than those seen with two-sided RTT-and the results are somewhat less accurate. At the same time, this method makes possible distance measurements for many APs that previously could not be used. This increased accessibility can compensate for the decreased accuracy of individual measurements. We demonstrate here indoor localization using one-sided RTT with respect to legacy APs that do not support IEEE 802.11-2016. The accuracy achieved is 3-4 m in cluttered environments with few line-of-sight readings (and using only 20 MHz bandwidths). This is not as good as for two-sided RTT, where 1-2 m accuracy has been achieved (using 80 MHz bandwidths), but adequate for many applications A wider Wi-Fi channel bandwidth would increase the accuracy further. As before, Bayesian grid update is the preferred method for determining position and positional accuracy, but the observation model now is different from that for two-sided RTT. As with two-sided RTT, the probability of an RTT measurement below the true distance is very low, but, in the other direction, the range of measurements for a given distance can be much wider (up to well over twice the actual distance). We describe methods for formulating useful observation models. As with two-sided RTT, the offset or bias in distance measurements has to be subtracted from the reported measurements. One difference is that here, the offsets are large (typically in the 2400-2700 m range) because of the "turn-around time" of roughly 16 μs (i.e., about two orders of magnitude larger than the time of flight one is attempting to measure). We describe methods for estimating these offsets and for minimizing the effort required to do so when setting up an installation with many APs.
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Affiliation(s)
- Berthold K P Horn
- Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
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15
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Wu H, He W, Shan C, Wang Z, Fu S, Tang Q, Guo H, Du Y, Liu W, Hu C. Achieving Remarkable Charge Density via Self-Polarization of Polar High-k Material in a Charge-Excitation Triboelectric Nanogenerator. Adv Mater 2022; 34:e2109918. [PMID: 35081267 DOI: 10.1002/adma.202109918] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/06/2021] [Revised: 01/18/2022] [Indexed: 05/28/2023]
Abstract
Boosting output charge density is top priority for achieving high-performance triboelectric nanogenerators (TENGs). The charge-excitation strategy is demonstrated to be a superior approach to acquire high output charge density. Meanwhile, the molecular charge behaviors in the dielectric under a strong electric field from high charge density bring new physics that are worth exploring. Here, a rapid self-polarization effect of a polar dielectric material by the superhigh electric field in a charge-excitation TENG is reported, by which the permittivity of the polar dielectric material realizes self-increase to a saturation, and thus enhances the output charge density. Consequently, an ultrahigh charge density of 3.53 mC m-2 is obtained with 7 µm homemade lead zirconate titanate-poly(vinylidene fluoride) composite film in the atmosphere with 5% relative humidity, which is the highest charge density for TENGs with high durability currently. This work provides new guidance for dielectric material optimization under charge excitation to boost the output performance of TENGs toward practical applications.
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Affiliation(s)
- Huiyuan Wu
- Department of Applied Physics, State Key Laboratory of Power Transmission Equipment & System Security and New Technology, Chongqing University, Chongqing, 400044, P. R. China
| | - Wencong He
- Department of Applied Physics, State Key Laboratory of Power Transmission Equipment & System Security and New Technology, Chongqing University, Chongqing, 400044, P. R. China
| | - Chuncai Shan
- Department of Applied Physics, State Key Laboratory of Power Transmission Equipment & System Security and New Technology, Chongqing University, Chongqing, 400044, P. R. China
| | - Zhao Wang
- Department of Applied Physics, State Key Laboratory of Power Transmission Equipment & System Security and New Technology, Chongqing University, Chongqing, 400044, P. R. China
| | - Shaoke Fu
- Department of Applied Physics, State Key Laboratory of Power Transmission Equipment & System Security and New Technology, Chongqing University, Chongqing, 400044, P. R. China
| | - Qian Tang
- Department of Applied Physics, State Key Laboratory of Power Transmission Equipment & System Security and New Technology, Chongqing University, Chongqing, 400044, P. R. China
| | - Hengyu Guo
- Department of Applied Physics, State Key Laboratory of Power Transmission Equipment & System Security and New Technology, Chongqing University, Chongqing, 400044, P. R. China
| | - Yan Du
- Department of Applied Physics, State Key Laboratory of Power Transmission Equipment & System Security and New Technology, Chongqing University, Chongqing, 400044, P. R. China
| | - Wenlin Liu
- College of Chemistry and Molecular Engineering, Peking University, Beijing, 100871, P. R. China
| | - Chenguo Hu
- Department of Applied Physics, State Key Laboratory of Power Transmission Equipment & System Security and New Technology, Chongqing University, Chongqing, 400044, P. R. China
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16
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Koutras KN, Tegopoulos SN, Charalampakos VP, Kyritsis A, Gonos IF, Pyrgioti EC. Breakdown Performance and Partial Discharge Development in Transformer Oil-Based Metal Carbide Nanofluids. Nanomaterials (Basel) 2022; 12:269. [PMID: 35055285 DOI: 10.3390/nano12020269] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/20/2021] [Revised: 01/10/2022] [Accepted: 01/12/2022] [Indexed: 12/04/2022]
Abstract
In this work, the influence of semi-conductive SiC nanoparticles on the AC breakdown voltage and partial discharge development in natural ester oil FR3 is examined. Primarily, the dielectric constant and the electrical conductivity of the nanoparticles are measured following the broadband dielectric spectroscopy technique. The nanoparticles are added into the matrix following the ultrasonication process in three weight percentage ratios in order for their effect to be evaluated as a function of their concentration inside the base oil. The processing of the results reveals that the nanofluid containing SiC nanoparticles at 0.004% w/w demonstrates the highest AC dielectric strength improvement and shows the greatest resistance to the appearance of partial discharge activity. The mechanisms behind the aforementioned results are discussed in detail and confirmed by the broadband dielectric spectroscopy technique, which reveals that this particular nanofluid sample is characterized by lower dielectric constant and electrical conductivity than the one with double the weight percentage ratio.
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Vitkova V, Yordanova V, Staneva G, Petkov O, Stoyanova-Ivanova A, Antonova K, Popkirov G. Dielectric Properties of Phosphatidylcholine Membranes and the Effect of Sugars. Membranes (Basel) 2021; 11:membranes11110847. [PMID: 34832076 PMCID: PMC8623822 DOI: 10.3390/membranes11110847] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Revised: 10/25/2021] [Accepted: 10/27/2021] [Indexed: 11/16/2022]
Abstract
Simple carbohydrates are associated with the enhanced risk of cardiovascular disease and adverse changes in lipoproteins in the organism. Conversely, sugars are known to exert a stabilizing effect on biological membranes, and this effect is widely exploited in medicine and industry for cryopreservation of tissues and materials. In view of elucidating molecular mechanisms involved in the interaction of mono- and disaccharides with biomimetic lipid systems, we study the alteration of dielectric properties, the degree of hydration, and the rotational order parameter and dipole potential of lipid bilayers in the presence of sugars. Frequency-dependent deformation of cell-size unilamellar lipid vesicles in alternating electric fields and fast Fourier transform electrochemical impedance spectroscopy are applied to measure the specific capacitance of phosphatidylcholine lipid bilayers in sucrose, glucose and fructose aqueous solutions. Alteration of membrane specific capacitance is reported in sucrose solutions, while preservation of membrane dielectric properties is established in the presence of glucose and fructose. We address the effect of sugars on the hydration and the rotational order parameter for 1-palmitoyl-2-oleoyl-sn-glycero-3- phosphocholine (POPC) and 1-stearoyl-2-oleoyl-sn-glycero-3- phosphocholine (SOPC). An increased degree of lipid packing is reported in sucrose solutions. The obtained results provide evidence that some small carbohydrates are able to change membrane dielectric properties, structure, and order related to membrane homeostasis. The reported data are also relevant to future developments based on the response of lipid bilayers to external physical stimuli such as electric fields and temperature changes.
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Affiliation(s)
- Victoria Vitkova
- Georgi Nadjakov Institute of Solid State Physics, Bulgarian Academy of Sciences, 72 Tsarigradsko Chaussee, Blvd., 1784 Sofia, Bulgaria; (O.P.); (A.S.-I.); (K.A.)
- Correspondence:
| | - Vesela Yordanova
- Institute of Biophysics and Biomedical Engineering, Bulgarian Academy of Sciences, Acad. G. Bonchev Str., Bl. 21, 1113 Sofia, Bulgaria; (V.Y.); (G.S.)
| | - Galya Staneva
- Institute of Biophysics and Biomedical Engineering, Bulgarian Academy of Sciences, Acad. G. Bonchev Str., Bl. 21, 1113 Sofia, Bulgaria; (V.Y.); (G.S.)
| | - Ognyan Petkov
- Georgi Nadjakov Institute of Solid State Physics, Bulgarian Academy of Sciences, 72 Tsarigradsko Chaussee, Blvd., 1784 Sofia, Bulgaria; (O.P.); (A.S.-I.); (K.A.)
| | - Angelina Stoyanova-Ivanova
- Georgi Nadjakov Institute of Solid State Physics, Bulgarian Academy of Sciences, 72 Tsarigradsko Chaussee, Blvd., 1784 Sofia, Bulgaria; (O.P.); (A.S.-I.); (K.A.)
| | - Krassimira Antonova
- Georgi Nadjakov Institute of Solid State Physics, Bulgarian Academy of Sciences, 72 Tsarigradsko Chaussee, Blvd., 1784 Sofia, Bulgaria; (O.P.); (A.S.-I.); (K.A.)
| | - Georgi Popkirov
- Central Laboratory of Solar Energy and New Energy Sources, Bulgarian Academy of Sciences, 72 Tsarigradsko Chaussee, Blvd., 1784 Sofia, Bulgaria;
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Chang CF, Kuo HY, Lee JP. AC measurements and simulations of hepatic radiofrequency ablation. Int J Hyperthermia 2021; 38:1322-1332. [PMID: 34477032 DOI: 10.1080/02656736.2021.1971779] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022] Open
Abstract
INTRODUCTION The radiofrequency ablation (RFA) of liver cancer is a desirable treatment option, as it is minimally invasive. An accurate numerical simulation can greatly help physicians better plan their surgical protocols. Previously, the displacement current in the RFA process was considered negligible, and therefore RFA simulation was modeled as a direct current (DC) system instead of an alternating current (AC) system. Our study investigated the hypothesis that the displacement current in the RFA process should not always be considered negligible. METHODS AC measurements of ex vivo bovine liver ablation were performed, and numerical simulations were also conducted to test the hypothesis that the relative permittivity would significantly decrease after the liver tissue reached a high temperature. RESULTS The displacement current was observed to be a sizable fraction of the conduction current, especially before the onset of the first pause. The simulation results indicated that the relative permittivity is likely to decrease to several hundred or lower at elevated temperatures. CONCLUSIONS Our study results suggest that the DC model may be inadequate, especially before the first roll-off and that additional information could be available during RFA treatment by considering the AC nature of RFA, which could lead to improved numerical simulation. Additional measurements of tissue parameters are needed to reach the full potential of the AC model for further development of ablation control.
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Affiliation(s)
- Chieh-Feng Chang
- Biomedical Technology and Device Research Laboratories, Industrial Technology Research Institute, Chutung, Taiwan
| | - Hsuan-Yu Kuo
- Biomedical Technology and Device Research Laboratories, Industrial Technology Research Institute, Chutung, Taiwan
| | - Jo-Ping Lee
- Biomedical Technology and Device Research Laboratories, Industrial Technology Research Institute, Chutung, Taiwan
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Lu H, Li Y, Zhang J. Design and Analysis of Broadband LiNbO 3 Optical Waveguide Electric Field Sensor with Tapered Antenna. Sensors (Basel) 2021; 21:3672. [PMID: 34070507 DOI: 10.3390/s21113672] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/15/2021] [Revised: 05/18/2021] [Accepted: 05/20/2021] [Indexed: 11/16/2022]
Abstract
The three-dimensional (3D) simulation model of a lithium niobate (LiNbO3, LN) optical waveguide (OWG) electric field sensor has been established by using the full-wave electromagnetic simulation software. The influences of the LN substrate and the packaging material on the resonance frequency of the integrated OWG electric field sensor have been simulated and analyzed. The simulation results show that the thickness of the LN substrate has a great influence on the resonant frequency of the sensor (≈33.4%). A sensor with a substrate thickness of 1 mm has been designed, fabricated, and experimentally investigated. Experimental results indicate that the measured resonance frequency is 7.5 GHz, which nearly coincides with the simulation results. Moreover, the sensor can be used for the measurement of the nanosecond electromagnetic impulse (NEMP) in the time domain from 1.29 kV/m to 100.97 kV/m.
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20
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Hwang PA, Ainsworth TL, Ouellette JD. Microwave Specular Measurements and Ocean Surface Wave Properties. Sensors (Basel) 2021; 21:1486. [PMID: 33672775 DOI: 10.3390/s21041486] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/29/2020] [Revised: 02/14/2021] [Accepted: 02/17/2021] [Indexed: 11/16/2022]
Abstract
Microwave reflectometers provide spectrally integrated information of ocean surface waves several times longer than the incident electromagnetic (EM) wavelengths. For high wind condition, it is necessary to consider the modification of relative permittivity by air in foam and whitecaps produced by wave breaking. This paper describes the application of these considerations to microwave specular returns from the ocean surface. Measurements from Ku and Ka band altimeters and L band reflectometers are used for illustration. The modeling yields a straightforward integration of a closed-form expression connecting the observed specular normalized radar cross section (NRCS) to the surface wave statistical and geometric properties. It remains a challenge to acquire sufficient number of high-wind collocated and simultaneous reference measurements for algorithm development or validation and verification effort. Solutions from accurate forward computation can supplement the sparse high wind databases. Modeled specular NRCSs are provided for L, C, X, Ku, and Ka bands with wind speeds up to 99 m/s.
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21
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Valeriano WW, Andrade RR, Vasco JP, Malachias A, Neves BRA, Guimarães PSS, Rodrigues WN. Mapping the local dielectric constant of a biological nanostructured system. Beilstein J Nanotechnol 2021; 12:139-150. [PMID: 33564609 PMCID: PMC7849231 DOI: 10.3762/bjnano.12.11] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/09/2020] [Accepted: 01/04/2021] [Indexed: 06/12/2023]
Abstract
The aim of this work is to determine the varying dielectric constant of a biological nanostructured system via electrostatic force microscopy (EFM) and to show how this method is useful to study natural photonic crystals. We mapped the dielectric constant of the cross section of the posterior wing of the damselfly Chalcopteryx rutilans with nanometric resolution. We obtained structural information on its constitutive nanolayers and the absolute values of their dielectric constant. By relating the measured profile of the static dielectric constant to the profile of the refractive index in the visible range, combined with optical reflectance measurements and simulation, we were able to describe the origin of the strongly iridescent wing colors of this Amazonian rainforest damselfly. The method we demonstrate here should be useful for the study of other biological nanostructured systems.
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Affiliation(s)
- Wescley Walison Valeriano
- Departamento de Física, ICEx, Universidade Federal de Minas Gerais, Av. Antônio Carlos 6627, 31270-901 Belo Horizonte, Minas Gerais, Brazil
| | - Rodrigo Ribeiro Andrade
- Centro de Microscopia, Universidade Federal de Minas Gerais, Av. Antônio Carlos 6627, 31270-901 Belo Horizonte, Minas Gerais, Brazil
| | - Juan Pablo Vasco
- Institute of Theoretical Physics, École Polytechnique Fédérale de Lausanne EPFL, CH-1015 Lausanne, Switzerland
| | - Angelo Malachias
- Departamento de Física, ICEx, Universidade Federal de Minas Gerais, Av. Antônio Carlos 6627, 31270-901 Belo Horizonte, Minas Gerais, Brazil
| | - Bernardo Ruegger Almeida Neves
- Departamento de Física, ICEx, Universidade Federal de Minas Gerais, Av. Antônio Carlos 6627, 31270-901 Belo Horizonte, Minas Gerais, Brazil
- Centro de Microscopia, Universidade Federal de Minas Gerais, Av. Antônio Carlos 6627, 31270-901 Belo Horizonte, Minas Gerais, Brazil
| | - Paulo Sergio Soares Guimarães
- Departamento de Física, ICEx, Universidade Federal de Minas Gerais, Av. Antônio Carlos 6627, 31270-901 Belo Horizonte, Minas Gerais, Brazil
| | - Wagner Nunes Rodrigues
- Departamento de Física, ICEx, Universidade Federal de Minas Gerais, Av. Antônio Carlos 6627, 31270-901 Belo Horizonte, Minas Gerais, Brazil
- Centro de Microscopia, Universidade Federal de Minas Gerais, Av. Antônio Carlos 6627, 31270-901 Belo Horizonte, Minas Gerais, Brazil
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22
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Ahmad A, Mishra B, Foley A, Wood L, Chen MY. High Permeability Photosintered Strontium Ferrite Flexible Thin Films. Micromachines (Basel) 2021; 12:42. [PMID: 33401412 DOI: 10.3390/mi12010042] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/15/2020] [Revised: 12/25/2020] [Accepted: 12/27/2020] [Indexed: 11/16/2022]
Abstract
The paper is focused on the development and optimization of strontium ferrite nanomaterial and photosintered flexible thin films. These magnetic thin films are characterized with direct current (DC) and high frequency measurements. For photosintered strontium ferrite samples, we achieved relative complex permeability of about 29.5-j1.8 and relative complex permittivity of about 12.9-j0.3 at a frequency of 5.9 GHz.
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Lee JH, Kim JS, Kim HJ, Park K, Moon J, Lee J, Park Y. Free Volume Effect via Various Chemical Structured Monomers on Adhesion Property and Relative Permittivity in Acrylic Pressure Sensitive Adhesives. Polymers (Basel) 2020; 12:E2633. [PMID: 33182559 DOI: 10.3390/polym12112633] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2020] [Revised: 11/05/2020] [Accepted: 11/05/2020] [Indexed: 11/26/2022] Open
Abstract
Acrylic pressure-sensitive adhesives (PSAs) are used as fixatives between layers of a display. PSAs’ function is an important factor that determines the performance of the display. Of the various display types available, the touch screen panel (TSP) of smart devices is firmly related to the relative permittivity of the elementals. Therefore, adjusting the relative permittivity of the PSA is indispensable for driving the TSP. Accordingly, selected acrylic pre-polymers were polymerized and the pre-polymer was blended and cross-linked with monomers with different chemical structure to adjust the relative permittivity. The monomers were hexametyldisiloxane (HMDS), N-vinylcaprolactam (NVC), tert-butyl acrylate (TBA), and isooctadecyl acrylate (ISTA). The gel fraction and transmittance as a function of the monomers show a similar result to the pure acrylic PSA. However, the gel fraction value decreased to about 90% and the transmittance decreased to about 85%, due to the immiscibility between nonpolar HMDS and acrylic PSA. On the other hand, the adhesion properties were improved when NVC was added because of the polarity of the nitrogen group. In addition, the relative permittivity of the PSA decreased regardless of the monomer chosen. There was, however, a difference in the optimal content of each monomer, and NVC decreased from 4 phr content to about 3.4 in reducing relative permittivity. Through the above results, it was confirmed that NVC having a nitrogen group is most advantageous in lowering adhesion properties and relative permittivity, and necessitates further research based on the findings.
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González-López G, Romeu J, Cairó I, Segura I, Ikumi T, Jofre-Roca L. Wireless Sensing of Concrete Setting Process. Sensors (Basel) 2020; 20:s20205965. [PMID: 33096912 PMCID: PMC7589881 DOI: 10.3390/s20205965] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/16/2020] [Revised: 10/13/2020] [Accepted: 10/19/2020] [Indexed: 11/16/2022]
Abstract
An RFID-based wireless system to measure the evolution of the setting process of cement-based materials is presented in this paper. The system consists of a wireless RFID temperature sensor that works embedded in concrete, and an external RFID reader that communicates with the embedded sensor to extract the temperature measurement conducted by the embedded sensor. Temperature time evolution is a well known proxy to monitor the setting process of concrete. The RFID sensor consisting of an UWB Bow Tie antenna with central frequency 868 MHz, matched to the EM4325 temperature chip through a T-match structure for embedded operation inside concrete is fully characterized. Results for measurements of the full set up conducted in a real-scenario are provided.
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Affiliation(s)
- Giselle González-López
- School of Telecommunication Engineering, Universitat Politècnica de Catalunya, 08034 Barcelona, Spain; (J.R.); (L.J.-R.)
- Correspondence:
| | - Jordi Romeu
- School of Telecommunication Engineering, Universitat Politècnica de Catalunya, 08034 Barcelona, Spain; (J.R.); (L.J.-R.)
| | | | - Ignacio Segura
- Department of Civil and Environmental Engineering, Universitat Politècnica de Catalunya, 08034 Barcelona, Spain; (I.S.); (T.I.)
- Smart Engineering, 08034 Barcelona, Spain
| | - Tai Ikumi
- Department of Civil and Environmental Engineering, Universitat Politècnica de Catalunya, 08034 Barcelona, Spain; (I.S.); (T.I.)
- Smart Engineering, 08034 Barcelona, Spain
| | - Lluis Jofre-Roca
- School of Telecommunication Engineering, Universitat Politècnica de Catalunya, 08034 Barcelona, Spain; (J.R.); (L.J.-R.)
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Jin L, Xiao X, Deng W, Nashalian A, He D, Raveendran V, Yan C, Su H, Chu X, Yang T, Li W, Yang W, Chen J. Manipulating Relative Permittivity for High-Performance Wearable Triboelectric Nanogenerators. Nano Lett 2020; 20:6404-6411. [PMID: 32584050 DOI: 10.1021/acs.nanolett.0c01987] [Citation(s) in RCA: 70] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
As the world marches into the era of the Internet of Things (IoT), the practice of human health care is on the cusp of a revolution, driven by an unprecedented level of personalization enabled by a variety of wearable bioelectronics. A sustainable and wearable energy solution is highly desired , but challenges still remain in its development. Here, we report a high-performance wearable electricity generation approach by manipulating the relative permittivity of a triboelectric nanogenerator (TENG). A compatible active carbon (AC)-doped polyvinylidene fluoride (AC@PVDF) composite film was invented with high relative permittivity and a specific surface area for wearable biomechanical energy harvesting. Compared with the pure PVDF, the 0.8% AC@PVDF film-based TENG obtained an enhancement in voltage, current, and power by 2.5, 3.5, and 9.8 times, respectively. This work reports a stable, cost-effective, and scalable approach to improve the performance of the triboelectric nanogenerator for wearable biomechanical energy harvesting, thus rendering a sustainable and pervasive energy solution for on-body electronics.
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Affiliation(s)
- Long Jin
- Key Laboratory of Advanced Technologies of Materials, Ministry of Education, School of Materials Science and Engineering, Southwest Jiaotong University, Chengdu 610031, China
| | - Xiao Xiao
- Department of Bioengineering, University of California, Los Angeles, Los Angeles, California 90095, United States
| | - Weili Deng
- Key Laboratory of Advanced Technologies of Materials, Ministry of Education, School of Materials Science and Engineering, Southwest Jiaotong University, Chengdu 610031, China
| | - Ardo Nashalian
- Department of Bioengineering, University of California, Los Angeles, Los Angeles, California 90095, United States
| | - Daren He
- Department of Bioengineering, University of California, Los Angeles, Los Angeles, California 90095, United States
| | - Vidhur Raveendran
- Department of Bioengineering, University of California, Los Angeles, Los Angeles, California 90095, United States
| | - Cheng Yan
- Key Laboratory of Advanced Technologies of Materials, Ministry of Education, School of Materials Science and Engineering, Southwest Jiaotong University, Chengdu 610031, China
| | - Hai Su
- Key Laboratory of Advanced Technologies of Materials, Ministry of Education, School of Materials Science and Engineering, Southwest Jiaotong University, Chengdu 610031, China
| | - Xiang Chu
- Key Laboratory of Advanced Technologies of Materials, Ministry of Education, School of Materials Science and Engineering, Southwest Jiaotong University, Chengdu 610031, China
| | - Tao Yang
- Key Laboratory of Advanced Technologies of Materials, Ministry of Education, School of Materials Science and Engineering, Southwest Jiaotong University, Chengdu 610031, China
| | - Wen Li
- Key Laboratory of Advanced Technologies of Materials, Ministry of Education, School of Materials Science and Engineering, Southwest Jiaotong University, Chengdu 610031, China
| | - Weiqing Yang
- Key Laboratory of Advanced Technologies of Materials, Ministry of Education, School of Materials Science and Engineering, Southwest Jiaotong University, Chengdu 610031, China
- State Key Laboratory of Traction Power, Southwest Jiaotong University, Chengdu 610031, China
| | - Jun Chen
- Department of Bioengineering, University of California, Los Angeles, Los Angeles, California 90095, United States
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Du B, Liu Q, Shi Y, Zhao Y. The Effect of Fe 3O 4 Nanoparticle Size on Electrical Properties of Nanofluid Impregnated Paper and Trapping Analysis. Molecules 2020; 25:E3566. [PMID: 32781514 DOI: 10.3390/molecules25163566] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2020] [Revised: 07/04/2020] [Accepted: 07/24/2020] [Indexed: 11/16/2022] Open
Abstract
This paper systematically studies the effect of Fe3O4 nanoparticle size on the insulation performance of nanofluid impregnated paper. Three kinds of Fe3O4 nanoparticles with different sizes and their nanofluid impregnated papers were prepared. Environmental scanning electron microscopy (ESEM) and infrared spectroscopy were used to analyze the combination of Fe3O4 nanoparticles and nanofluid impregnated paper. The effect of nanoparticle size on breakdown voltage and several dielectric characteristics, e.g., permittivity, dielectric loss, of the nanofluid impregnated paper were comparatively investigated. Studies show that the Fe3O4 nanoparticles were bound to impregnated paper fibers by O-H bonds, while the relative permittivity and dielectric loss of the nanofluid impregnated papers were increased. Meanwhile, the increase of trap depth, caused by the nanoparticles, can trap the electric charge and improve the breakdown strength. The test results show that the direct current (DC) and alternating current (AC) breakdown voltages of nanofluid impregnated paper increased by 9.1% and 10.0% compared to FR3 nanofluid impregnated paper, respectively.
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Abstract
The IEEE 802.11mc WiFi standard provides a protocol for a cellphone to measure its distance from WiFi access points (APs). The position of the cellphone can then be estimated from the reported distances using known positions of the APs. There are several “multilateration” methods that work in relatively open environments. The problem is harder in a typical residence where signals pass through walls and floors. There, Bayesian cell update has shown particular promise. The Bayesian grid update method requires an “observation model” which gives the conditional probability of observing a reported distance given a known actual distance. The parameters of an observation model may be fitted using scattergrams of reported distances versus actual distance. We show here that the problem of fitting an observation model can be reduced from two dimensions to one. We further show that, perhaps surprisingly, a “double exponential” observation model fits real data well. Generating the test data involves knowing not only the positions of the APs but also that of the cellphone. Manual determination of positions can limit the scale of test data collection. We show here that “boot strapping,” using results of a Bayesian grid update method as a proxy for the actual position, can provide an accurate observation model, and a good observation model can nearly double the accuracy of indoor positioning. Finally, indoors, reported distance measurements are biased to be mostly longer than the actual distances. An attempt is made here to detect this bias and compensate for it.
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28
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Han J, Gao Y, Nan X, Liu F, Xin SX. Statistical analysis of the accuracy of water content-based electrical properties tomography. NMR Biomed 2020; 33:e4273. [PMID: 32048385 DOI: 10.1002/nbm.4273] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/18/2019] [Revised: 01/04/2020] [Accepted: 01/24/2020] [Indexed: 06/10/2023]
Abstract
Water content-based electrical properties tomography (wEPT) can retrieve electrical properties (EPs) from water content maps, thereby eliminating the need for B1 field measurement in the traditional magnetic resonance electrical properties tomography method. The wEPT is performed by conventional MR scanning, such as T1 -weighted spin-echo imaging, and thus can be directly applied to clinical settings. However, the random noise propagation involved in wEPT causes inaccuracy in EP mapping. To guarantee the EP estimates desired for clinical practice, this study statically investigates the noise-specific uncertainty of wEPT through probability density function models. We calculated the probability distribution of EP maps with different noise levels and examined the effects of scan parameters on reconstruction accuracy with various flip angles (FAs) and repetition time (TR) settings. The theoretical derivation was validated by Monte Carlo simulations and human imaging experiment at 3 T. Results showed that a serious deviation could occur in tissues with large conductivity value at a low signal-to-noise ratio and quantitatively demonstrate that such deviation could be mitigated by increased FAs or TRs. This study provided useful information for the setup of scan parameters, evaluation of accuracy of the wEPT under specific SNR levels, and promote its clinical applications.
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Affiliation(s)
- Jijun Han
- School of Biomedical Engineering, Southern Medical University, Guangzhou, Guangdong, China
| | - Yunyu Gao
- School of Biomedical Engineering, Southern Medical University, Guangzhou, Guangdong, China
| | - Xiang Nan
- Center for Biomedical Engineering, University of Science and Technology of China, Hefei, Anhui, China
| | - Feng Liu
- School of Information Technology and Electrical Engineering, University of Queensland, Brisbane, QLD, Australia
| | - Sherman Xuegang Xin
- School of Biomedical Engineering, Southern Medical University, Guangzhou, Guangdong, China
- School of Medicine, South China University of Technology, Guangzhou, Guangdong, China
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29
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Ellingford C, Zhang R, Wemyss AM, Zhang Y, Brown OB, Zhou H, Keogh P, Bowen C, Wan C. Self-Healing Dielectric Elastomers for Damage-Tolerant Actuation and Energy Harvesting. ACS Appl Mater Interfaces 2020; 12:7595-7604. [PMID: 31944651 DOI: 10.1021/acsami.9b21957] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
The actuation and energy-harvesting performance of dielectric elastomers are strongly related to their intrinsic electrical and mechanical properties. For future resilient smart transducers, a fast actuation response, efficient energy-harvesting performance, and mechanical robustness are key requirements. In this work, we demonstrate that poly(styrene-butadiene-styrene) (SBS) can be converted into a self-healing dielectric elastomer with high permittivity and low dielectric loss, which can be deformed to large mechanical strains; these are key requirements for actuation and energy-harvesting applications. Using a one-step click reaction at room temperature for 20 min, methyl-3-mercaptopropionate (M3M) was grafted to SBS and reached 95.2% of grafting ratios. The resultant M3M-SBS can be deformed to a high mechanical strain of 1000%, with a relative permittivity of εr = 7.5 and a low tan δ = 0.03. When used in a dielectric actuator, it can provide 9.2% strain at an electric field of 39.5 MV m-1 and can also generate an energy density of 11 mJ g-1 from energy harvesting. After being subjected to mechanical damage, the self-healed elastomer can recover 44% of its breakdown strength during energy harvesting. This work demonstrates a facile route to produce self-healing, high permittivity, and low dielectric loss elastomers for both actuation and energy harvesting, which is applicable to a wide range of diene elastomer systems.
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Affiliation(s)
- Christopher Ellingford
- International Institute for Nanocomposites Manufacturing (IINM), WMG , University of Warwick , Coventry CV4 7AL , U.K
| | - Runan Zhang
- Department of Mechanical Engineering , University of Bath , Bath BA2 7AY , U.K
| | - Alan M Wemyss
- International Institute for Nanocomposites Manufacturing (IINM), WMG , University of Warwick , Coventry CV4 7AL , U.K
| | - Yan Zhang
- Department of Mechanical Engineering , University of Bath , Bath BA2 7AY , U.K
| | - Oliver B Brown
- International Institute for Nanocomposites Manufacturing (IINM), WMG , University of Warwick , Coventry CV4 7AL , U.K
| | - Hongzhao Zhou
- Department of Mechanical Engineering , University of Bath , Bath BA2 7AY , U.K
| | - Patrick Keogh
- Department of Mechanical Engineering , University of Bath , Bath BA2 7AY , U.K
| | - Christopher Bowen
- Department of Mechanical Engineering , University of Bath , Bath BA2 7AY , U.K
| | - Chaoying Wan
- International Institute for Nanocomposites Manufacturing (IINM), WMG , University of Warwick , Coventry CV4 7AL , U.K
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Yu X, Sun Y, Cai K, Yu H, Zhou D, Lu D, Xin SX. Dielectric Properties of Normal and Metastatic Lymph Nodes Ex Vivo From Lung Cancer Surgeries. Bioelectromagnetics 2020; 41:148-155. [PMID: 31912926 DOI: 10.1002/bem.22246] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2019] [Accepted: 12/26/2019] [Indexed: 12/26/2022]
Abstract
The dielectric properties of normal and tumor human tissues have been widely reported in recent years. However, the dielectric properties of intrathoracic lymph nodes (LNs) have not been reported. In this communication, we measured the dielectric properties (i.e., permittivity and conductivity) of ex vivo intrathoracic LNs obtained from lung cancer surgeries. Results show that the permittivity and conductivity of metastatic LNs are higher than those of normal LNs over the frequency range of 1 MHz-4 GHz. Statistically significant differences are observed at single specific frequencies (64, 128, 298, 433, and 915 MHz and 2.45 GHz). Our study provides the basic data to support future-related research and fills the research gap on the dielectric properties of LNs in the lungs. Bioelectromagnetics. 2020;41:148-155. © 2020 Bioelectromagnetics Society.
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Affiliation(s)
- Xuefei Yu
- School of Biomedical Engineering, Southern Medical University, Guangzhou, China
| | - Ying Sun
- School of Biomedical Engineering, Southern Medical University, Guangzhou, China
| | - Kaican Cai
- Department of Thoracic Surgery, Nanfang Hospital, Southern Medical University, Guangzhou, China
| | - Hongfeng Yu
- School of Biomedical Engineering, Southern Medical University, Guangzhou, China
| | - Difu Zhou
- Department of Medical Equipment, The Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, China
| | - Di Lu
- Department of Thoracic Surgery, Nanfang Hospital, Southern Medical University, Guangzhou, China
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31
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González-López G, Jofre Roca L, Amorós García de Valdecasas S, Rodríguez-Leor O, Gálvez-Montón C, Bayés-Genís A, O'Callaghan J. Resonance-Based Microwave Technique for Body Implant Sensing. Sensors (Basel) 2019; 19:E4828. [PMID: 31698742 DOI: 10.3390/s19224828] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/14/2019] [Revised: 10/31/2019] [Accepted: 11/04/2019] [Indexed: 11/17/2022]
Abstract
There is an increasing need for safe and simple techniques for sensing devices and prostheses implanted inside the human body. Microwave wireless inspection may be an appropriate technique for it. The implanted device may have specific characteristics that allow to distinguish it from its environment. A new sensing technique based on the principle of differential resonance is proposed and its basic parameters are discussed. This technique allows to use the implant as a signal scattering device and to detect changes produced in the implant based on the corresponding change in its scattering signature. The technique is first tested with a canonic human phantom and then applied to a real in vivo clinical experiment to detect coronary stents implanted in swine animals.
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32
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Harvey AH. Influence of Isotopologue Dipole Moments on Precision Dielectric-Constant Measurements. J Res Natl Inst Stand Technol 2019; 124:1-4. [PMID: 34877162 PMCID: PMC7339741 DOI: 10.6028/jres.124.031] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 10/30/2019] [Indexed: 06/13/2023]
Abstract
Measurements of the relative permittivity (static dielectric constant) of fluids such as methane have been interpreted with the assumption of zero dipole moment. This assumption is not strictly true, due to the presence of isotopologues with small, nonzero dipole moments. We investigate the significance of this effect by analyzing the effect of the dipole of CH3D on the static dielectric constant of methane. It is found that the isotopologue effect is more than two orders of magnitude smaller than the uncertainty of the best existing measurements. Similar estimates for other compounds such as H2 and CO2 produce even smaller effects. Therefore, the interpretation of these measurements with a dipole moment of zero remains valid.
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Affiliation(s)
- Allan H Harvey
- National Institute of Standards and Technology, Boulder, CO 80305, USA
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33
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Fendri A, Kallel AY, Nouri H, Ghariani H, Kanoun O. Measurement System for Lossy Capacitive Sensors: Application to Edible Oils Quality Assessment. Sensors (Basel) 2019; 19:E4299. [PMID: 31590210 DOI: 10.3390/s19194299] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/01/2019] [Revised: 09/28/2019] [Accepted: 09/29/2019] [Indexed: 11/16/2022]
Abstract
This paper aimed to develop a portable, low-cost, and easy-to-use measurement system for oil quality degradation assessment. The main two chemical parameters affected by frying are the total polar compounds (TPC) and free fatty acids. The system should characterize the change of chemical parameters by measuring the changes in its dielectric parameters. The dielectric parameters, relative permittivity, and conductivity are measured by measuring the capacitance and resistance of a capacitive sensor dipped in oil. The main challenges are that the corresponding changes of the capacitance and resistance are very small and the presence of stray effects. For this reason, the measurement system should be able to detect changes in capacitance and resistance with high resolution and with good immunity to stray effects. The proposed measurement system is based on the conversion of impedance to voltage and time and combining, therefore, having two measurement methods in one circuit. In this way, it is possible to measure the dielectric and resistive parameters and not only the relative permittivity as was done in previous works. The results showed a strong correlation between the chemical and electrical parameters with a coefficient of determination in the range of 0.9.
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34
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Hong WT, Yu JD, Kim SY, Lee JS. Dynamic Cone Penetrometer Incorporated with Time Domain Reflectometry (TDR) Sensors for the Evaluation of Water Contents in Sandy Soils. Sensors (Basel) 2019; 19:s19183841. [PMID: 31491983 PMCID: PMC6767109 DOI: 10.3390/s19183841] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/16/2019] [Revised: 08/25/2019] [Accepted: 09/02/2019] [Indexed: 11/16/2022]
Abstract
Ground moisture content and strength properties are the most important factors for a proper assessment of ground stability. This study developed a dynamic cone penetrometer incorporated with time domain reflectometry (TDR) sensors (TDCP). The TDCP is composed of an anvil, a driving rod, and a TDCP probe. Three wave guides and a K-type thermocouple are installed on the TDCP probe. For utilization of TDCP, relationships between relative permittivities measured by TDCP and those measured by standard TDR probe, temperature, and volumetric water content of the soils were investigated. In addition, the relationship between penetration indices by TDCP (TPI) and by standard dynamic cone penetrometer was established. In the field application test, relative permittivity, ground temperature, and TPI were measured along the depth. Moreover, gravimetric water contents were also measured for comparison. The experimental results showed that volumetric water contents compensated by ground temperature showed good agreement with the volumetric water contents estimated from the gravimetric water contents of the soil samples and TPI. This study suggests that the TDCP may be effectively used for the evaluation moisture contents and for the strength characterization of the subsurface.
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Affiliation(s)
- Won-Taek Hong
- Department of Civil and Environmental Engineering, University of Illinois at Urbana-Champaign, 205, North Mathews Avenue, Urbana, IL 61801, USA
- School of Civil, Environmental and Architectural Engineering, Korea University, 145, Anam-ro, Seongbuk-gu, Seoul 02841, Korea
| | - Jung-Doung Yu
- School of Civil, Environmental and Architectural Engineering, Korea University, 145, Anam-ro, Seongbuk-gu, Seoul 02841, Korea
| | - Sang Yeob Kim
- School of Civil, Environmental and Architectural Engineering, Korea University, 145, Anam-ro, Seongbuk-gu, Seoul 02841, Korea
| | - Jong-Sub Lee
- School of Civil, Environmental and Architectural Engineering, Korea University, 145, Anam-ro, Seongbuk-gu, Seoul 02841, Korea.
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35
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Fei Y, Su L, Lou H, Zhao C, Wang Y, Chen G. The effects of 50 Hz magnetic field-exposed cell culture medium on cellular functions in FL cells. J Radiat Res 2019; 60:424-431. [PMID: 31111909 PMCID: PMC6640911 DOI: 10.1093/jrr/rrz020] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/29/2018] [Revised: 02/22/2019] [Indexed: 05/19/2023]
Abstract
Although extremely low frequency magnetic fields (ELF-MFs) have been classified as a possible carcinogen for humans by the International Agency for Research on Cancer (IARC), their biological effects and underlying mechanisms are still unclear. Our previous study indicated that ELF-MF exposure influenced the relative permittivity of the saline solution, suggesting that the MF exposure altered physical properties of the solution. To explore the biophysical mechanism of ELF-MF-induced biological effects, this study examined the effects of 50 Hz sinusoidal MF at 0-4.0 mT on the permittivity of culture medium with phase-interrogation surface plasmon resonance (SPR) sensing. Then, the biological effects of MF pre-exposed culture medium on cell viability, the mitogen-activated protein kinase (MAPK) signaling pathways, oxidative stress, and genetic stabilities were analyzed using Cell Counting Kit-8, western blot, flow cytometry, γH2AX foci formation, and comet assay. The results showed that SPR signals were decreased under MF exposure in a time- and dose-dependent manner, and the decreased SPR signals were reversible when the exposure was drawn off. However, MF pre-exposed culture medium did not significantly change cell viability, intracellular reactive oxygen species level, activation of the MARK signaling pathways, or genetic stabilities in human amniotic epithelial cells (FL cells). In conclusion, our data suggest that the relative permittivity of culture medium was influenced by 50 Hz MF exposure, but this change did not affect the biological processes in FL cells.
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Affiliation(s)
- Yue Fei
- Bioelectromagnetics Laboratory, and Department of Reproductive Endocrinology of Women’s Hospital, Zhejiang University School of Medicine, 866 Yuhangtang Road, Hangzhou, China
| | - Liling Su
- Bioelectromagnetics Laboratory, and Department of Reproductive Endocrinology of Women’s Hospital, Zhejiang University School of Medicine, 866 Yuhangtang Road, Hangzhou, China
- Department of Clinical Medicine, Jiangxi Medical College, Zhimin Road, Shangrao, China
| | - Haifeng Lou
- Bioelectromagnetics Laboratory, and Department of Reproductive Endocrinology of Women’s Hospital, Zhejiang University School of Medicine, 866 Yuhangtang Road, Hangzhou, China
| | - Chuning Zhao
- Bioelectromagnetics Laboratory, and Department of Reproductive Endocrinology of Women’s Hospital, Zhejiang University School of Medicine, 866 Yuhangtang Road, Hangzhou, China
| | - Yiqin Wang
- State Key Laboratory of Modern Optical Instrumentation (Zhejiang University), Centre for Optical and Electromagnetics Research, Zhejiang Provincial Key Laboratory for Sensing Technologies, JORCEP (Sino-Swedish Joint Research Center of Photonics), Zhejiang University, 866 Yuhangtang Road, Hangzhou, China
| | - Guangdi Chen
- Bioelectromagnetics Laboratory, and Department of Reproductive Endocrinology of Women’s Hospital, Zhejiang University School of Medicine, 866 Yuhangtang Road, Hangzhou, China
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36
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Yang D, Zhang X, Wang K, Wu C, Yang R, Hou Y, Jiang Y, Liu S, Priya S. Stable Efficiency Exceeding 20.6% for Inverted Perovskite Solar Cells through Polymer-Optimized PCBM Electron-Transport Layers. Nano Lett 2019; 19:3313-3320. [PMID: 30986075 DOI: 10.1021/acs.nanolett.9b00936] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
Fullerene derivative, such as [6,6]-phenyl C61 butyric acid methyl ester (PCBM), is widely used as an electron-transport layer (ETL) in inverted perovskite solar cell (PSC). However, its low electron mobility, complexity in achieving quality film formation, and severe nonradiative recombination at perovskite/PCBM interface due to the large electron capture region, lead to lower efficiency for inverted PSCs compared to the normal structures. Herein, we demonstrate an effective and practical strategy to overcome these challenges. Conjugated n-type polymeric materials are mixed together with PCBM to form a homogeneous bulk-mixed (HBM) continuous film with high electron mobility and suitable energy level. HBM film is found to completely cap the perovskite surface to enhance the electron extraction. The critical electron capture radius of the HBM decreases to 12.52 nm from 14.89 nm of PCBM due to the large relative permittivity, resulting in reduced nonradiative recombination at perovskite/HBM interface. The efficiency of inverted PSCs with HBM ETLs exceeds 20.6% with a high fill factor of 0.82. Further, the stability of devices is improved owing to the high hydrophobicity of the HBM ETLs. Under ambient air condition after 45 days, the efficiency of inverted PSCs based on HBM remains 80% of the initial value. This is significantly higher than the control devices which retain only 48% of the initial value under similar aging conditions. We believe these breakthroughs in improving efficiency and stability of inverted PSCs will expedite their transition.
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Affiliation(s)
- Dong Yang
- Materials Science and Engineering , Pennsylvania State University , University Park, Pennsylvania 16802 , United States
| | - Xiaorong Zhang
- Key Laboratory of Applied Surface and Colloid Chemistry, Ministry of Education; Shaanxi Engineering Lab for Advanced Energy Technology, School of Materials Science and Engineering , Shaanxi Normal University , Xi'an 710119 , China
| | - Kai Wang
- Materials Science and Engineering , Pennsylvania State University , University Park, Pennsylvania 16802 , United States
| | - Congcong Wu
- Materials Science and Engineering , Pennsylvania State University , University Park, Pennsylvania 16802 , United States
| | - Ruixia Yang
- Key Laboratory of Applied Surface and Colloid Chemistry, Ministry of Education; Shaanxi Engineering Lab for Advanced Energy Technology, School of Materials Science and Engineering , Shaanxi Normal University , Xi'an 710119 , China
| | - Yuchen Hou
- Materials Science and Engineering , Pennsylvania State University , University Park, Pennsylvania 16802 , United States
| | - Yuanyuan Jiang
- Materials Science and Engineering , Pennsylvania State University , University Park, Pennsylvania 16802 , United States
| | - Shengzhong Liu
- Dalian National Laboratory for Clean Energy, iChEM, Dalian Institute of Chemical Physics , Chinese Academy of Sciences , 457 Zhongshan Road , Dalian 116023 , China
- Key Laboratory of Applied Surface and Colloid Chemistry, Ministry of Education; Shaanxi Engineering Lab for Advanced Energy Technology, School of Materials Science and Engineering , Shaanxi Normal University , Xi'an 710119 , China
| | - Shashank Priya
- Materials Science and Engineering , Pennsylvania State University , University Park, Pennsylvania 16802 , United States
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Tsai B, Xue H, Birgersson E, Ollmar S, Birgersson U. Dielectrical Properties of Living Epidermis and Dermis in the Frequency Range from 1 kHz to 1 MHz. J Electr Bioimpedance 2019; 10:14-23. [PMID: 33584878 PMCID: PMC7531215 DOI: 10.2478/joeb-2019-0003] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/28/2018] [Indexed: 06/01/2023]
Abstract
We determine the in-vivo dielectric properties-resistivity and relative permittivity-of living epidermis and dermis of human skin soaked with a physiological saline solution for one minute between 1 kHz and 1 MHz. This is done by fitting approximate analytical solutions of a mechanistic model for the transport of charges in these layers to a training set comprising impedance measurements at two depth settings on stripped skin on the volar forearm of 24 young subjects. Here, the depth settings are obtained by varying the voltage at a second inject on the electrical-impedance-spectroscopy probe. The model and the dielectric properties are validated with a test set for a third depth setting with overall good agreement. In addition, the means and standard deviations of the thicknesses of living epidermis and dermis are estimated from a literature review as 61±7 μm and 1.0±0.2 mm respectively. Furthermore, extensions to resolve the skin layers in more detail are suggested.
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Affiliation(s)
- B. Tsai
- Department of Chemical and Biomolecular Engineering, National University of Singapore, 4 Engineering Drive 4, Singapore, Singapore117585
| | - H. Xue
- Department of Chemical and Biomolecular Engineering, National University of Singapore, 4 Engineering Drive 4, Singapore, Singapore117585
| | - E. Birgersson
- Department of Mechanical Engineering, National University of Singapore, 5 Engineering Drive 2, Singapore, Singapore117576
| | - S. Ollmar
- Department of Clinical Science, Intervention and Technology, Karolinska Institutet, SE-14186StockholmSweden
| | - U. Birgersson
- Department of Clinical Science, Intervention and Technology, Karolinska Institutet, SE-14186StockholmSweden
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38
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Hornak J, Trnka P, Kadlec P, Michal O, Mentlík V, Šutta P, Csányi GM, Tamus ZÁ. Magnesium Oxide Nanoparticles: Dielectric Properties, Surface Functionalization and Improvement of Epoxy-Based Composites Insulating Properties. Nanomaterials (Basel) 2018; 8:E381. [PMID: 29848967 PMCID: PMC6027305 DOI: 10.3390/nano8060381] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/09/2018] [Revised: 05/18/2018] [Accepted: 05/23/2018] [Indexed: 11/17/2022]
Abstract
Composite insulation materials are an inseparable part of numerous electrical devices because of synergy effect between their individual parts. One of the main aims of the presented study is an introduction of the dielectric properties of nanoscale magnesium oxide powder via Broadband Dielectric Spectroscopy (BDS). These unique results present the behavior of relative permittivity and loss factor in frequency and temperature range. Following the current trends in the application of inorganic nanofillers, this article is complemented by the study of dielectric properties (dielectric strength, volume resistivity, dissipation factor and relative permittivity) of epoxy-based composites depending on the filler amount (0, 0.5, 0.75, 1 and 1.25 weight percent). These parameters are the most important for the design and development of the insulation systems. The X-ray diffraction patterns are presented for pure resin and resin with optimal filler amount (1 wt %), which was estimated according to measurement results. Magnesium oxide nanoparticles were also treated by addition of silane coupling agent ( γ -Glycidoxypropyltrimethoxysilane), in the case of optimal filler loading (1 wt %) as well. Besides previously mentioned parameters, the effects of surface functionalization have been observed by two unique measurement and evaluation techniques which have never been used for this evaluation, i.e., reduced resorption curves (RRCs) and voltage response method (VR). These methods (developed in our departments), extend the possibilities of measurement of composite dielectric responses related to DC voltage application, allow the facile comparability of different materials and could be used for dispersion level evaluation. This fact has been confirmed by X-ray diffraction analyses.
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Affiliation(s)
- Jaroslav Hornak
- Department of Technologies and Measurement, Faculty of Electrical Engineering, University of West Bohemia, Univerzitní 8, 306 14 Pilsen, Czech Republic.
| | - Pavel Trnka
- Department of Technologies and Measurement, Faculty of Electrical Engineering, University of West Bohemia, Univerzitní 8, 306 14 Pilsen, Czech Republic.
| | - Petr Kadlec
- Department of Technologies and Measurement, Faculty of Electrical Engineering, University of West Bohemia, Univerzitní 8, 306 14 Pilsen, Czech Republic.
| | - Ondřej Michal
- Department of Technologies and Measurement, Faculty of Electrical Engineering, University of West Bohemia, Univerzitní 8, 306 14 Pilsen, Czech Republic.
| | - Václav Mentlík
- Department of Technologies and Measurement, Faculty of Electrical Engineering, University of West Bohemia, Univerzitní 8, 306 14 Pilsen, Czech Republic.
| | - Pavol Šutta
- New Technologies-Research Centre, University of West Bohemia, Univerzitní 8, 306 14 Pilsen, Czech Republic.
| | - Gergely Márk Csányi
- Department of Electric Power Engineering, Faculty of Electrical Engineering and Informatics, Budapest University of Technology of Economics, Egry J. Street 18., H-1111 Budapest, Hungary.
| | - Zoltán Ádám Tamus
- Department of Electric Power Engineering, Faculty of Electrical Engineering and Informatics, Budapest University of Technology of Economics, Egry J. Street 18., H-1111 Budapest, Hungary.
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Lee K, Hassan A, Lee CH, Bae J. Microstrip Patch Sensor for Salinity Determination. Sensors (Basel) 2017; 17:s17122941. [PMID: 29258273 PMCID: PMC5751091 DOI: 10.3390/s17122941] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/21/2017] [Revised: 12/11/2017] [Accepted: 12/15/2017] [Indexed: 11/30/2022]
Abstract
In this paper, a compact microstrip feed inset patch sensor is proposed for measuring the salinities in seawater. The working principle of the proposed sensor depends on the fact that different salinities in liquid have different relative permittivities and cause different resonance frequencies. The proposed sensor can obtain better sensitivity to salinity changes than common sensors using conductivity change, since the relative permittivity change to salinity is 2.5 times more sensitive than the conductivity change. The patch and ground plane of the proposed sensor are fabricated by conductive copper spray coating on the masks made by 3D printer. The fabricated patch and the ground plane are bonded to a commercial silicon substrate and then attached to 5 mm-high chamber made by 3D printer so that it contains only 1 mL seawater. For easy fabrication and testing, the maximum resonance frequency was selected under 3 GHz and to cover salinities in real seawater, it was assumed that the salinity changes from 20 to 35 ppt. The sensor was designed by the finite element method-based ANSYS high-frequency structure simulator (HFSS), and it can detect the salinity with 0.01 ppt resolution. The designed sensor has a resonance frequency separation of 37.9 kHz and reflection coefficients under −20 dB at the resonant frequencies. The fabricated sensor showed better performance with average frequency separation of 48 kHz and maximum reflection coefficient of −35 dB. By comparing with the existing sensors, the proposed compact and low-cost sensor showed a better detection capability. Therefore, the proposed patch sensor can be utilized in radio frequency (RF) tunable sensors for salinity determination.
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Affiliation(s)
- Kibae Lee
- Research Institute, Kyungwon Co. Ltd., Siheung 15084, Korea;
| | - Arshad Hassan
- Department of Ocean System Engineering, Jeju National University, Jeju 690-756, Korea;
- Department of Electrical Engineering, National University of Computer and Emerging Sciences, Foundation for Advancement of Science and Technology (NUCES-FAST), H 11/4, Islamabad 44000, Pakistan;
| | - Chong Hyun Lee
- Department of Ocean System Engineering, Jeju National University, Jeju 690-756, Korea;
- Correspondence: ; Tel.: +82-64-754-3481
| | - Jinho Bae
- Department of Ocean System Engineering, Jeju National University, Jeju 690-756, Korea;
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Ianniello C, de Zwart JA, Duan Q, Deniz CM, Alon L, Lee JS, Lattanzi R, Brown R. Synthesized tissue-equivalent dielectric phantoms using salt and polyvinylpyrrolidone solutions. Magn Reson Med 2017; 80:413-419. [PMID: 29159985 DOI: 10.1002/mrm.27005] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2017] [Revised: 10/03/2017] [Accepted: 10/23/2017] [Indexed: 11/11/2022]
Abstract
PURPOSE To explore the use of polyvinylpyrrolidone (PVP) for simulated materials with tissue-equivalent dielectric properties. METHODS PVP and salt were used to control, respectively, relative permittivity and electrical conductivity in a collection of 63 samples with a range of solute concentrations. Their dielectric properties were measured with a commercial probe and fitted to a 3D polynomial in order to establish an empirical recipe. The material's thermal properties and MR spectra were measured. RESULTS The empirical polynomial recipe (available at https://www.amri.ninds.nih.gov/cgi-bin/phantomrecipe) provides the PVP and salt concentrations required for dielectric materials with permittivity and electrical conductivity values between approximately 45 and 78, and 0.1 to 2 siemens per meter, respectively, from 50 MHz to 4.5 GHz. The second- (solute concentrations) and seventh- (frequency) order polynomial recipe provided less than 2.5% relative error between the measured and target properties. PVP side peaks in the spectra were minor and unaffected by temperature changes. CONCLUSION PVP-based phantoms are easy to prepare and nontoxic, and their semitransparency makes air bubbles easy to identify. The polymer can be used to create simulated material with a range of dielectric properties, negligible spectral side peaks, and long T2 relaxation time, which are favorable in many MR applications. Magn Reson Med 80:413-419, 2018. © 2017 International Society for Magnetic Resonance in Medicine.
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Affiliation(s)
- Carlotta Ianniello
- Center for Advanced Imaging Innovation and Research (CAI2R) and Center for Biomedical Imaging, Department of Radiology, New York University School of Medicine, New York, New York, USA.,The Sackler Institute of Graduate Biomedical Science, New York University School of Medicine, New York, New York, USA
| | - Jacco A de Zwart
- Laboratory of Functional and Molecular Imaging, NINDS, National Institutes of Health, Bethesda, Maryland, USA
| | - Qi Duan
- Laboratory of Functional and Molecular Imaging, NINDS, National Institutes of Health, Bethesda, Maryland, USA
| | - Cem M Deniz
- Center for Advanced Imaging Innovation and Research (CAI2R) and Center for Biomedical Imaging, Department of Radiology, New York University School of Medicine, New York, New York, USA
| | - Leeor Alon
- Center for Advanced Imaging Innovation and Research (CAI2R) and Center for Biomedical Imaging, Department of Radiology, New York University School of Medicine, New York, New York, USA
| | - Jae-Seung Lee
- Center for Advanced Imaging Innovation and Research (CAI2R) and Center for Biomedical Imaging, Department of Radiology, New York University School of Medicine, New York, New York, USA
| | - Riccardo Lattanzi
- Center for Advanced Imaging Innovation and Research (CAI2R) and Center for Biomedical Imaging, Department of Radiology, New York University School of Medicine, New York, New York, USA.,The Sackler Institute of Graduate Biomedical Science, New York University School of Medicine, New York, New York, USA
| | - Ryan Brown
- Center for Advanced Imaging Innovation and Research (CAI2R) and Center for Biomedical Imaging, Department of Radiology, New York University School of Medicine, New York, New York, USA
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Harvey AH, Mountain RD. Correlations for the Dielectric Constants of H 2S, SO 2, and SF 6. Int J Thermophys 2017; 38:147. [PMID: 29651192 PMCID: PMC5890340 DOI: 10.1007/s10765-017-2279-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/01/2017] [Accepted: 08/01/2017] [Indexed: 06/08/2023]
Abstract
A new method is developed for correlating the static dielectric constant of polar fluids over wide ranges of conditions where few experimental data exist. Molecular dynamics simulations are used to establish the temperature and density dependence of the Kirkwood g-factor, and also the functional form for the increase of the effective dipole moment with density. Most parameters in the model are obtained entirely from simulation; a single proportionality constant is adjusted to obtain agreement with the limited experimental data. The method is applied to hydrogen sulfide (H2S) and sulfur dioxide (SO2), both of which are important in geochemistry but have only a few dielectric data available. The resulting correlations agree well with the available liquid data, obey physical boundary conditions at low density and at high temperature, and interpolate in density and temperature in a physically reasonable manner. In addition, we present a more conventional correlation for the dielectric constant of sulfur hexafluoride, SF6, where more data are available.
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Affiliation(s)
- Allan H Harvey
- Applied Chemicals and Materials Division, National Institute of Standards and Technology, 325 Broadway, Boulder, CO 80305, 303-497-3555
| | - Raymond D Mountain
- Chemical Sciences Division, National Institute of Standards and Technology, 100 Bureau Drive, Gaithersburg, MD 20899
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Xiong J, Wu G, Tan Q, Wei T, Wu D, Shen S, Dong H, Zhang W. Dielectrically-Loaded Cylindrical Resonator-Based Wireless Passive High-Temperature Sensor. Sensors (Basel) 2016; 16:E2037. [PMID: 27916920 DOI: 10.3390/s16122037] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/14/2016] [Revised: 11/18/2016] [Accepted: 11/24/2016] [Indexed: 11/16/2022]
Abstract
The temperature sensor presented in this paper is based on a microwave dielectric resonator, which uses alumina ceramic as a substrate to survive in harsh environments. The resonant frequency of the resonator is determined by the relative permittivity of the alumina ceramic, which monotonically changes with temperature. A rectangular aperture etched on the surface of the resonator works as both an incentive and a coupling device. A broadband slot antenna fed by a coplanar waveguide is utilized as an interrogation antenna to wirelessly detect the sensor signal using a radio-frequency backscattering technique. Theoretical analysis, software simulation, and experiments verified the feasibility of this temperature-sensing system. The sensor was tested in a metal-enclosed environment, which severely interferes with the extraction of the sensor signal. Therefore, frequency-domain compensation was introduced to filter the background noise and improve the signal-to-noise ratio of the sensor signal. The extracted peak frequency was found to monotonically shift from 2.441 to 2.291 GHz when the temperature was varied from 27 to 800 °C, leading to an average absolute sensitivity of 0.19 MHz/°C.
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Rajala S, Siponkoski T, Sarlin E, Mettänen M, Vuoriluoto M, Pammo A, Juuti J, Rojas OJ, Franssila S, Tuukkanen S. Cellulose Nanofibril Film as a Piezoelectric Sensor Material. ACS Appl Mater Interfaces 2016; 8:15607-14. [PMID: 27232271 DOI: 10.1021/acsami.6b03597] [Citation(s) in RCA: 100] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/19/2023]
Abstract
Self-standing films (45 μm thick) of native cellulose nanofibrils (CNFs) were synthesized and characterized for their piezoelectric response. The surface and the microstructure of the films were evaluated with image-based analysis and scanning electron microscopy (SEM). The measured dielectric properties of the films at 1 kHz and 9.97 GHz indicated a relative permittivity of 3.47 and 3.38 and loss tangent tan δ of 0.011 and 0.071, respectively. The films were used as functional sensing layers in piezoelectric sensors with corresponding sensitivities of 4.7-6.4 pC/N in ambient conditions. This piezoelectric response is expected to increase remarkably upon film polarization resulting from the alignment of the cellulose crystalline regions in the film. The CNF sensor characteristics were compared with those of polyvinylidene fluoride (PVDF) as reference piezoelectric polymer. Overall, the results suggest that CNF is a suitable precursor material for disposable piezoelectric sensors, actuators, or energy generators with potential applications in the fields of electronics, sensors, and biomedical diagnostics.
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Affiliation(s)
- Satu Rajala
- Department of Automation Science and Engineering, Tampere University of Technology , P.O. Box 692, FI-33101 Tampere, Finland
| | - Tuomo Siponkoski
- Microelectronics Research Unit, Faculty of Information Technology and Electrical Engineering, University of Oulu , P.O. Box 4500, FI-90014 Oulu, Finland
| | - Essi Sarlin
- Department of Materials Science, Tampere University of Technology , P.O. Box 589, FI-33101 Tampere, Finland
| | - Marja Mettänen
- Department of Automation Science and Engineering, Tampere University of Technology , P.O. Box 692, FI-33101 Tampere, Finland
| | - Maija Vuoriluoto
- Department of Forest Products Technology, School of Chemical Technology, Aalto University , P.O. Box 16300, FI-00076 Aalto, Espoo, Finland
| | - Arno Pammo
- Department of Automation Science and Engineering, Tampere University of Technology , P.O. Box 692, FI-33101 Tampere, Finland
| | - Jari Juuti
- Microelectronics Research Unit, Faculty of Information Technology and Electrical Engineering, University of Oulu , P.O. Box 4500, FI-90014 Oulu, Finland
| | - Orlando J Rojas
- Department of Forest Products Technology, School of Chemical Technology, Aalto University , P.O. Box 16300, FI-00076 Aalto, Espoo, Finland
| | - Sami Franssila
- Department of Materials Science and Engineering, School of Chemical Technology, Aalto University , P.O. Box 11000, FI-00076 Aalto, Espoo, Finland
| | - Sampo Tuukkanen
- Department of Automation Science and Engineering, Tampere University of Technology , P.O. Box 692, FI-33101 Tampere, Finland
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Abstract
Modeling of mineral reaction equilibria and aqueous-phase speciation of C-O-H fluids requires the dielectric constant of the fluid mixture, which is not known from experiment and is typically estimated by some rule for mixing pure-component values. In order to evaluate different proposed mixing rules, we use molecular dynamics simulation to calculate the dielectric constant of a model H2O-CO2 mixture at temperatures of 700 K and 1000 K at pressures up to 3 GPa. We find that theoretically based mixing rules that depend on combining the molar polarizations of the pure fluids systematically overestimate the dielectric constant of the mixture, as would be expected for mixtures of nonpolar and strongly polar components. The commonly used semiempirical mixing rule due to Looyenga works well for this system at the lower pressures studied, but somewhat underestimates the dielectric constant at higher pressures and densities, especially at the water-rich end of the composition range.
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Berndt A, Pospiech D, Jehnichen D, Häußler L, Voit B, Al-Hussein M, Plötner M, Kumar A, Fischer WJ. Methacrylate Copolymers with Liquid Crystalline Side Chains for Organic Gate Dielectric Applications. ACS Appl Mater Interfaces 2015; 7:12339-12347. [PMID: 25496492 DOI: 10.1021/am5069479] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
UNLABELLED Polymers for all-organic field-effect transistors are under development to cope with the increasing demand for novel materials for organic electronics. Besides the semiconductor, the dielectric layer determines the efficiency of the final device. Poly(methyl methacrylate) (PMMA) is a frequently used dielectric. In this work, the chemical structure of this material was stepwise altered by incorporation of cross-linkable and/or self-organizing comonomers to improve the chemical stability and the dielectric properties. Different types of cross-linking methods were used to prevent dissolution, swelling or intermixing of the dielectric e.g. during formation processes of top electrodes or semiconducting layers. Self-organizing comonomers were expected to influence the dielectric/semiconductor interface, and moreover, to enhance the chemical resistance of the dielectric. Random copolymers were obtained by free radical and reversible addition-fragmentation chain transfer (RAFT) polymerization. With 6-[4-(4'-cyanophenyl)phenoxy]alkyl side chains having hexyl or octyl spacer, thermotropic liquid crystalline (LC) behavior and nanophase separation into smectic layers was observed, while copolymerization with methyl methacrylate induced molecular disorder. In addition to chemical, thermal and structural properties, electrical characteristics like breakdown field strength (EBD) and relative permittivity (k) were determined. The dielectric films were studied in metal-insulator-metal setups. EBD appeared to be strongly dependent on the type of electrode used and especially the ink formulation. Cross-linking of PMMA yielded an increase in EBD up to 4.0 MV/cm with Ag and 5.7 MV/cm with PEDOT PSS electrodes because of the increased solvent resistance. The LC side chains reduce the ability for cross-linking resulting in decreased breakdown field strengths.
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Affiliation(s)
- Andreas Berndt
- †Organic Chemistry of Polymers, Technische Universität Dresden, 01069 Dresden, Germany
- ‡Leibniz-Institut für Polymerforschung Dresden e.V., Hohe Straße 6, 01069 Dresden, Germany
- §Center for Advancing Electronics Dresden (cfaed), Technische Universität Dresden, 01062 Dresden, Germany
| | - Doris Pospiech
- ‡Leibniz-Institut für Polymerforschung Dresden e.V., Hohe Straße 6, 01069 Dresden, Germany
- §Center for Advancing Electronics Dresden (cfaed), Technische Universität Dresden, 01062 Dresden, Germany
| | - Dieter Jehnichen
- ‡Leibniz-Institut für Polymerforschung Dresden e.V., Hohe Straße 6, 01069 Dresden, Germany
| | - Liane Häußler
- ‡Leibniz-Institut für Polymerforschung Dresden e.V., Hohe Straße 6, 01069 Dresden, Germany
| | - Brigitte Voit
- †Organic Chemistry of Polymers, Technische Universität Dresden, 01069 Dresden, Germany
- ‡Leibniz-Institut für Polymerforschung Dresden e.V., Hohe Straße 6, 01069 Dresden, Germany
- §Center for Advancing Electronics Dresden (cfaed), Technische Universität Dresden, 01062 Dresden, Germany
| | | | - Matthias Plötner
- §Center for Advancing Electronics Dresden (cfaed), Technische Universität Dresden, 01062 Dresden, Germany
- ⊥Institute of Semiconductors and Microsystems, Microsystems Technology, Technische Universität Dresden, 01069 Dresden, Germany
| | - Amit Kumar
- §Center for Advancing Electronics Dresden (cfaed), Technische Universität Dresden, 01062 Dresden, Germany
- ⊥Institute of Semiconductors and Microsystems, Microsystems Technology, Technische Universität Dresden, 01069 Dresden, Germany
| | - Wolf-Joachim Fischer
- §Center for Advancing Electronics Dresden (cfaed), Technische Universität Dresden, 01062 Dresden, Germany
- ⊥Institute of Semiconductors and Microsystems, Microsystems Technology, Technische Universität Dresden, 01069 Dresden, Germany
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Zhao XJ, Zhu G, Wang ZL. Coplanar induction enabled by asymmetric permittivity of dielectric materials for mechanical energy conversion. ACS Appl Mater Interfaces 2015; 7:6025-6029. [PMID: 25734360 DOI: 10.1021/acsami.5b00019] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Triboelectric nanogenerator (TENG) is a newly emerged technology for harvesting mechanical energy, which has the promise for various practical applications. Here, we introduce a new principle of TENG in which induced current is generated between two coplanar electrodes because of different dielectric fillers of distinct permittivities. The manipulation of permittivity of dielectric materials for TENG is first reported, demonstrating a novel route in designing high-performance TENGs. When repeatedly contacting with an object, a TENG having lateral dimensions of 21 mm × 10 mm can produce an open-circuit voltage of 58.5 V and a short-circuit current of 44.7 μA. The instantaneous output power density can reach up to 708 μW. Besides, the new design incorporates all electrodes into a single plane, greatly simplifying the structure, promoting robustness, and providing a viable solution for device miniaturization.
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Affiliation(s)
- Xue Jiao Zhao
- †Beijing Institute of Nanoenergy and Nanosystems, Chinese Academy of Sciences, Beijing 100083, China
| | - Guang Zhu
- †Beijing Institute of Nanoenergy and Nanosystems, Chinese Academy of Sciences, Beijing 100083, China
| | - Zhong Lin Wang
- †Beijing Institute of Nanoenergy and Nanosystems, Chinese Academy of Sciences, Beijing 100083, China
- ‡School of Materials Science and Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332, United States
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McPeak K, Jayanti SV, Kress SJP, Meyer S, Iotti S, Rossinelli A, Norris DJ. Plasmonic Films Can Easily Be Better: Rules and Recipes. ACS Photonics 2015; 2:326-333. [PMID: 25950012 PMCID: PMC4416469 DOI: 10.1021/ph5004237] [Citation(s) in RCA: 321] [Impact Index Per Article: 35.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/12/2014] [Revised: 02/03/2015] [Accepted: 02/03/2015] [Indexed: 05/20/2023]
Abstract
High-quality materials are critical for advances in plasmonics, especially as researchers now investigate quantum effects at the limit of single surface plasmons or exploit ultraviolet- or CMOS-compatible metals such as aluminum or copper. Unfortunately, due to inexperience with deposition methods, many plasmonics researchers deposit metals under the wrong conditions, severely limiting performance unnecessarily. This is then compounded as others follow their published procedures. In this perspective, we describe simple rules collected from the surface-science literature that allow high-quality plasmonic films of aluminum, copper, gold, and silver to be easily deposited with commonly available equipment (a thermal evaporator). Recipes are also provided so that films with optimal optical properties can be routinely obtained.
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Chew KM, Sudirman R, Seman N, Yong CY. Reflection coefficient detection of simulation models for microwave imaging simulation system. Biomed Mater Eng 2013; 24:199-207. [PMID: 24211899 DOI: 10.3233/bme-130800] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
The study was conducted based on two objectives as framework. The first objective is to determine the point of microwave signal reflection while penetrating into the simulation models and, the second objective is to analyze the reflection pattern when the signal penetrate into the layers with different relative permittivity, εr. Thus, several microwave models were developed to make a close proximity of the in vivo human brain. The study proposed two different layers on two different characteristics models. The radii on the second layer and the corresponding antenna positions are the factors for both models. The radii for model 1 is 60 mm with an antenna position of 10 mm away, in contrast, model 2 is 10 mm larger in size with a closely adapted antenna without any gap. The layers of the models were developed with different combination of materials such as Oil, Sandy Soil, Brain, Glycerin and Water. Results show the combination of Glycerin + Brain and Brain + Sandy Soil are the best proximity of the in vivo human brain grey and white matter. The results could benefit subsequent studies for further enhancement and development of the models.
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Affiliation(s)
- Kim Mey Chew
- Faculty of Electrical Engineering, Universiti Teknologi Malaysia, 81310 UTM Johor Bahru, Johor, Malaysia
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Gongadze E, van Rienen U, Kralj-Iglič V, Iglič A. Spatial variation of permittivity of an electrolyte solution in contact with a charged metal surface: a mini review. Comput Methods Biomech Biomed Engin 2012; 16:463-80. [PMID: 22263808 PMCID: PMC3664910 DOI: 10.1080/10255842.2011.624769] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2011] [Revised: 09/14/2011] [Indexed: 11/14/2022]
Abstract
Contact between a charged metal surface and an electrolyte implies a particular ion distribution near the charged surface, i.e. the electrical double layer. In this mini review, different mean-field models of relative (effective) permittivity are described within a simple lattice model, where the orientational ordering of water dipoles in the saturation regime is taken into account. The Langevin-Poisson-Boltzmann (LPB) model of spatial variation of the relative permittivity for point-like ions is described and compared to a more general Langevin-Bikerman (LB) model of spatial variation of permittivity for finite-sized ions. The Bikerman model and the Poisson-Boltzmann model are derived as limiting cases. It is shown that near the charged surface, the relative permittivity decreases due to depletion of water molecules (volume-excluded effect) and orientational ordering of water dipoles (saturation effect). At the end, the LPB and LB models are generalised by also taking into account the cavity field.
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Affiliation(s)
- E. Gongadze
- Laboratory of Biophysics, Faculty of Electrical Engineering, University of Ljubljana, Ljubljana, Slovenia
| | - U. van Rienen
- Faculty of Computer Science and Electrical Engineering, University of Rostock, Rostock, Germany
| | - V. Kralj-Iglič
- Laboratory of Clinical Biophysics, Faculty of Medicine, University of Ljubljana, Ljubljana, Slovenia
| | - A. Iglič
- Laboratory of Biophysics, Faculty of Electrical Engineering, University of Ljubljana, Ljubljana, Slovenia
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