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Zhou Z, Tang W, Xu T, Zhao W, Zhang J, Bai C. Flexible Strain Sensors Based on Thermoplastic Polyurethane Fabricated by Electrospinning: A Review. SENSORS (BASEL, SWITZERLAND) 2024; 24:4793. [PMID: 39123838 PMCID: PMC11314693 DOI: 10.3390/s24154793] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/18/2024] [Revised: 07/11/2024] [Accepted: 07/22/2024] [Indexed: 08/12/2024]
Abstract
Over recent years, thermoplastic polyurethane (TPU) has been widely used as a substrate material for flexible strain sensors due to its remarkable mechanical flexibility and the ease of combining various conductive materials by electrospinning. Many research advances have been made in the preparation of flexible strain sensors with better ductility, higher sensitivity, and wider sensing range by using TPU in combination with various conductive materials through electrospinning. However, there is a lack of reviews that provide a systematic and comprehensive summary and outlook of recent research advances in this area. In this review paper, the working principles of strain sensors and electrospinning technology are initially described. Subsequently, recent advances in strain sensors based on electrospun TPU are tracked and discussed, with a focus on the incorporation of various conductive fillers such as carbonaceous materials, MXene, metallic materials, and conductive polymers. Moreover, the wide range of applications of electrospun TPU flexible strain sensors is thoroughly discussed. Finally, the future prospects and challenges of electrospun TPU flexible strain sensors in various fields are pointed out.
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Affiliation(s)
| | | | | | | | - Jingjing Zhang
- School of Tropical Agriculture and Forestry, Hainan University, Danzhou 571799, China; (Z.Z.); (W.T.); (T.X.); (W.Z.)
| | - Chuanwu Bai
- School of Tropical Agriculture and Forestry, Hainan University, Danzhou 571799, China; (Z.Z.); (W.T.); (T.X.); (W.Z.)
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2
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Jeong YH, Kwon M, Shin S, Lee J, Kim KS. Biomedical Applications of CNT-Based Fibers. BIOSENSORS 2024; 14:137. [PMID: 38534244 DOI: 10.3390/bios14030137] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/13/2024] [Revised: 02/29/2024] [Accepted: 03/02/2024] [Indexed: 03/28/2024]
Abstract
Carbon nanotubes (CNTs) have been regarded as emerging materials in various applications. However, the range of biomedical applications is limited due to the aggregation and potential toxicity of powder-type CNTs. To overcome these issues, techniques to assemble them into various macroscopic structures, such as one-dimensional fibers, two-dimensional films, and three-dimensional aerogels, have been developed. Among them, carbon nanotube fiber (CNTF) is a one-dimensional aggregate of CNTs, which can be used to solve the potential toxicity problem of individual CNTs. Furthermore, since it has unique properties due to the one-dimensional nature of CNTs, CNTF has beneficial potential for biomedical applications. This review summarizes the biomedical applications using CNTF, such as the detection of biomolecules or signals for biosensors, strain sensors for wearable healthcare devices, and tissue engineering for regenerating human tissues. In addition, by considering the challenges and perspectives of CNTF for biomedical applications, the feasibility of CNTF in biomedical applications is discussed.
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Affiliation(s)
- Yun Ho Jeong
- School of Chemical Engineering, Pusan National University, Busan 46241, Republic of Korea
| | - Mina Kwon
- School of Chemical Engineering, Pusan National University, Busan 46241, Republic of Korea
| | - Sangsoo Shin
- School of Chemical Engineering, Pusan National University, Busan 46241, Republic of Korea
| | - Jaegeun Lee
- School of Chemical Engineering, Pusan National University, Busan 46241, Republic of Korea
- Department of Organic Material Science and Engineering, Pusan National University, Busan 46241, Republic of Korea
| | - Ki Su Kim
- School of Chemical Engineering, Pusan National University, Busan 46241, Republic of Korea
- Department of Organic Material Science and Engineering, Pusan National University, Busan 46241, Republic of Korea
- Institute of Advanced Organic Materials, Pusan National University, Busan 46241, Republic of Korea
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3
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Qu M, Xie Z, Liu S, Zhang J, Peng S, Li Z, Lin C, Nilsson F. Electric Resistance of Elastic Strain Sensors-Fundamental Mechanisms and Experimental Validation. NANOMATERIALS (BASEL, SWITZERLAND) 2023; 13:1813. [PMID: 37368243 DOI: 10.3390/nano13121813] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/09/2023] [Revised: 05/27/2023] [Accepted: 06/03/2023] [Indexed: 06/28/2023]
Abstract
Elastic strain sensor nanocomposites are emerging materials of high scientific and commercial interest. This study analyzes the major factors influencing the electrical behavior of elastic strain sensor nanocomposites. The sensor mechanisms were described for nanocomposites with conductive nanofillers, either dispersed inside the polymer matrix or coated onto the polymer surface. The purely geometrical contributions to the change in resistance were also assessed. The theoretical predictions indicated that maximum Gauge values are achieved for mixture composites with filler fractions slightly above the electrical percolation threshold, especially for nanocomposites with a very rapid conductivity increase around the threshold. PDMS/CB and PDMS/CNT mixture nanocomposites with 0-5.5 vol.% fillers were therefore manufactured and analyzed with resistivity measurements. In agreement with the predictions, the PDMS/CB with 2.0 vol.% CB gave very high Gauge values of around 20,000. The findings in this study will thus facilitate the development of highly optimized conductive polymer composites for strain sensor applications.
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Affiliation(s)
- Muchao Qu
- School of Automobile and Transportation Engineering, Guangdong Polytechnic Normal University, Guangzhou 510450, China
| | - Zixin Xie
- School of Automobile and Transportation Engineering, Guangdong Polytechnic Normal University, Guangzhou 510450, China
| | - Shuiyan Liu
- Guangzhou Highteen Plastics Co., Ltd., Guangzhou 510800, China
| | - Jinzhu Zhang
- Guangzhou Highteen Plastics Co., Ltd., Guangzhou 510800, China
| | - Siyao Peng
- School of Automobile and Transportation Engineering, Guangdong Polytechnic Normal University, Guangzhou 510450, China
| | - Zhitong Li
- School of Automobile and Transportation Engineering, Guangdong Polytechnic Normal University, Guangzhou 510450, China
| | - Cheng Lin
- School of Automobile and Transportation Engineering, Guangdong Polytechnic Normal University, Guangzhou 510450, China
| | - Fritjof Nilsson
- KTH Royal Institute of Technology, School of Chemical Science and Engineering, Fibre and Polymer Technology, SE-100 44 Stockholm, Sweden
- FSCN Research Centre, Mid Sweden University, SE-103 92 Sundsvall, Sweden
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4
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Haridas A, Sharma S, Naskar K, Mondal T. Cross-Talk Signal Free Recyclable Thermoplastic Polyurethane/Graphene-Based Strain and Pressure Sensor for Monitoring Human Motions. ACS APPLIED MATERIALS & INTERFACES 2023; 15:17279-17292. [PMID: 36944054 DOI: 10.1021/acsami.3c01364] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
Developing a sensor that can read out cross-talk free signals while determining various active physiological parameters is demanding in the field of point-of-care applications. While there are a few examples of non-flexible sensors available, the management of electronic waste generated from such sensors is critical. Most of such available sensors are rigid in form factor and hence limit their usability in healthcare monitoring due to their poor conformity to human skin. Combining these facets, studies on the development of a recyclable cross-talk free flexible sensor for monitoring human motions and active parameters are far and few. In this work, we report on the development of a recyclable flexible sensor that can provide accurate data for detecting small changes in strain as well as pressure. The developed sensor could decipher the signals individually responsible due to strain as well as pressure. Hence, it can deliver a cross-talk free output. Thermoplastic polyurethane and graphene were selected as the model system. The thermoplastic polyurethane/graphene sensor exhibited a tensile strain sensitivity of GF ≃ 3.375 for 0-100% strain and 10.551 for 100-150% strain and a pressure sensitivity of ∼-0.25 kPa-1. We demonstrate the applicability of the strain sensor for monitoring a variety of human motions ranging from a very small strain of eye blinking to a large strain of elbow bending with unambiguous peaks and a very fast response and recovery time of 165 ms. The signals received are mostly electrical hysteresis free. To confirm the recyclability, the developed sensor was recycled up to three times. Marginal decrement in the sensitivity was noted with recycling without compromising the sensing capabilities. These findings promise to open up a new avenue for developing flexible sensors with lesser carbon footprints.
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Affiliation(s)
- Ajay Haridas
- Rubber Technology Centre, Indian Institute of Technology Kharagpur, Kharagpur 721302, India
| | - Simran Sharma
- Rubber Technology Centre, Indian Institute of Technology Kharagpur, Kharagpur 721302, India
| | - Kinsuk Naskar
- Rubber Technology Centre, Indian Institute of Technology Kharagpur, Kharagpur 721302, India
| | - Titash Mondal
- Rubber Technology Centre, Indian Institute of Technology Kharagpur, Kharagpur 721302, India
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5
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Ertugrul I, Ulkir O, Ersoy S, Ragulskis M. Additive Manufactured Strain Sensor Using Stereolithography Method with Photopolymer Material. Polymers (Basel) 2023; 15:polym15040991. [PMID: 36850274 PMCID: PMC9965623 DOI: 10.3390/polym15040991] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2022] [Revised: 02/10/2023] [Accepted: 02/14/2023] [Indexed: 02/19/2023] Open
Abstract
As a result of the developments in additive manufacturing (AM) technology, 3D printing is transforming from a method used only in rapid prototyping to a technique used to produce large-scale equipment. This study presents the fabrication and experimental studies of a 3D-printed strain sensor that can be used directly in soft applications. Photopolymer-based conductive and flexible ultraviolet (UV) resin materials are used in the fabrication of the sensor. A Stereolithography (SLA)-based printer is preferred for 3D fabrication. The bottom base of the sensor, which consists of two parts, is produced from flexible UV resin, while the channels that should be conductive are produced from conductive UV resin. In total, a strain sensor with a thickness of 2 mm was produced. Experimental studies were carried out under loading and unloading conditions to observe the hysteresis effect of the sensor. The results showed a close linear relationship between the strain sensor and the measured resistance value. In addition, tensile test specimens were produced to observe the behavior of conductive and non-conductive materials. The tensile strength values obtained from the test results will provide information about the sensor placement. In addition, the flexible structure of the strain sensor will ensure its usability in many soft applications.
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Affiliation(s)
- Ishak Ertugrul
- Department of Mathematical Modelling, Kaunas University of Technology, 44138 Kaunas, Lithuania
- Correspondence:
| | - Osman Ulkir
- Department of Electric and Energy, Mus Alparslan University, 49250 Mus, Turkey
| | - Sezgin Ersoy
- Department of Mechatronic Engineering, Marmara University, 34565 Istanbul, Turkey
| | - Minvydas Ragulskis
- Department of Mathematical Modelling, Kaunas University of Technology, 44138 Kaunas, Lithuania
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6
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Wang Y, Cui TR, Gou GY, Li XS, Qiao YC, Li D, Xu JD, Guo YZ, Tian H, Yang Y, Ren TL. An Ultra-Sensitive and Multifunctional Electronic Skin with Synergetic Network of Graphene and CNT. NANOMATERIALS (BASEL, SWITZERLAND) 2022; 13:179. [PMID: 36616089 PMCID: PMC9823652 DOI: 10.3390/nano13010179] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/29/2022] [Revised: 12/21/2022] [Accepted: 12/27/2022] [Indexed: 06/17/2023]
Abstract
Electronic skin (e-skin) has attracted tremendous interest due to its diverse potential applications, including in physiological signal detection, health monitoring, and artificial throats. However, the major drawbacks of traditional e-skin are the weak adhesion of substrates, incompatibility between sensitivity and stretchability, and its single function. These shortcomings limit the application of e-skin and increase the complexity of its multifunctional integration. Herein, the synergistic network of crosslinked SWCNTs within and between multilayered graphene layers was directly drip coated onto the PU thin film with self-adhesion to fabricate versatile e-skin. The excellent mechanical properties of prepared e-skin arise from the sufficient conductive paths guaranteed by SWCNTs in small and large deformation under various strains. The prepared e-skin exhibits a low detection limit, as small as 0.5% strain, and compatibility between sensitivity and stretchability with a gauge factor (GF) of 964 at a strain of 0-30%, and 2743 at a strain of 30-60%. In physiological signals detection application, the e-skin demonstrates the detection of subtle motions, such as artery pulse and blinking, as well as large body motions, such as knee joint bending, elbow movement, and neck movement. In artificial throat application, the e-skin integrates sound recognition and sound emitting and shows clear and distinct responses between different throat muscle movements and different words for sound signal acquisition and recognition, in conjunction with superior sound emission performance with a sound spectrum response of 71 dB (f = 12.5 kHz). Overall, the presented comprehensive study of novel materials, structures, properties, and mechanisms offers promising potential in physiological signals detection and artificial throat applications.
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Affiliation(s)
- Yu Wang
- School of Integrated Circuit, Tsinghua University, Beijing 100084, China
- Beijing National Research Center for Information Science and Technology (BNRist), Tsinghua University, Beijing 100084, China
| | - Tian-Rui Cui
- School of Integrated Circuit, Tsinghua University, Beijing 100084, China
- Beijing National Research Center for Information Science and Technology (BNRist), Tsinghua University, Beijing 100084, China
| | - Guang-Yang Gou
- School of Integrated Circuit, Tsinghua University, Beijing 100084, China
- Beijing National Research Center for Information Science and Technology (BNRist), Tsinghua University, Beijing 100084, China
| | - Xiao-Shi Li
- School of Integrated Circuit, Tsinghua University, Beijing 100084, China
- Beijing National Research Center for Information Science and Technology (BNRist), Tsinghua University, Beijing 100084, China
| | - Yan-Cong Qiao
- School of Integrated Circuit, Tsinghua University, Beijing 100084, China
- Beijing National Research Center for Information Science and Technology (BNRist), Tsinghua University, Beijing 100084, China
| | - Ding Li
- School of Integrated Circuit, Tsinghua University, Beijing 100084, China
- Beijing National Research Center for Information Science and Technology (BNRist), Tsinghua University, Beijing 100084, China
| | - Jian-Dong Xu
- School of Integrated Circuit, Tsinghua University, Beijing 100084, China
- Beijing National Research Center for Information Science and Technology (BNRist), Tsinghua University, Beijing 100084, China
| | - Yi-Zhe Guo
- School of Integrated Circuit, Tsinghua University, Beijing 100084, China
- Beijing National Research Center for Information Science and Technology (BNRist), Tsinghua University, Beijing 100084, China
| | - He Tian
- School of Integrated Circuit, Tsinghua University, Beijing 100084, China
- Beijing National Research Center for Information Science and Technology (BNRist), Tsinghua University, Beijing 100084, China
| | - Yi Yang
- School of Integrated Circuit, Tsinghua University, Beijing 100084, China
- Beijing National Research Center for Information Science and Technology (BNRist), Tsinghua University, Beijing 100084, China
| | - Tian-Ling Ren
- School of Integrated Circuit, Tsinghua University, Beijing 100084, China
- Beijing National Research Center for Information Science and Technology (BNRist), Tsinghua University, Beijing 100084, China
- Center for Flexible Electronics Technology, Tsinghua University, Beijing 100084, China
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7
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You J, Zhang J, Zhang J, Yang Z, Zhang X. Stretchable and Highly Sensitive Strain Sensor Based on a 2D MXene and 1D Whisker Carbon Nanotube Binary Composite Film. ACS APPLIED MATERIALS & INTERFACES 2022; 14:55812-55820. [PMID: 36475594 DOI: 10.1021/acsami.2c18135] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
We fabricate a 2D MXene and 1D whisker carbon nanotube (WCNT) binary composite, where the MXene layer was sandwiched between two WCNT films, and assemble a flexible resistive-type strain sensor using this composite film. The deformations of the conductive networks trigged by the external mechanical stimuli cause the variations of the number of effective conductive paths, which result in the changes of the electric resistance of composite films. The resistances of the MXene/WCNT composite films that carry the strain information about the external mechanical stimuli are monitored. In addition, we demonstrate the role of the conductive MXene networks and the WCNT networks in responding to the external mechanical stimuli. The MXene networks dominate the variations of the resistance of the strain sensors in the low strain range. In the middle strain range, the deformations of both the MXene networks and the WCNT networks are responsible for the variations of the resistance of the strain sensors. In the high strain range, an "island bridge" like conductive network forms, where MXenes act as islands and WCNTs connect the adjacent MXene islands like bridges. The multiple types of conductive networks lead to the high sensitivity of the MXene/WCNT-based strain sensors over a wide strain range and a wide response window. This stretchable strain sensor exhibits good performances in detecting human muscle motions with a wide strain range and has the potentials of being applicable to wearable electronics.
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Affiliation(s)
- Junbo You
- School of Physical Science and Technology, Soochow University, Suzhou 215006, China
- Center for Soft Condensed Matter Physics and Interdisciplinary Research, Soochow University, Suzhou 215006, China
| | - Jiapeng Zhang
- School of Physical Science and Technology, Soochow University, Suzhou 215006, China
- Center for Soft Condensed Matter Physics and Interdisciplinary Research, Soochow University, Suzhou 215006, China
| | - Jinling Zhang
- School of Physical Science and Technology, Soochow University, Suzhou 215006, China
- Center for Soft Condensed Matter Physics and Interdisciplinary Research, Soochow University, Suzhou 215006, China
| | - Zhaohui Yang
- School of Physical Science and Technology, Soochow University, Suzhou 215006, China
- Center for Soft Condensed Matter Physics and Interdisciplinary Research, Soochow University, Suzhou 215006, China
- Jiangsu Key Laboratory of Thin Films, Soochow University, Suzhou 215006, China
| | - Xiaohua Zhang
- School of Physical Science and Technology, Soochow University, Suzhou 215006, China
- Center for Soft Condensed Matter Physics and Interdisciplinary Research, Soochow University, Suzhou 215006, China
- Jiangsu Key Laboratory of Thin Films, Soochow University, Suzhou 215006, China
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8
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Lee G, Lee C, Kim H, Jeon Y, Shul YG, Park J. Bifunctional 1,2,4-Triazole/12-Tungstophosphoric Acid Composite Nanoparticles for Biodiesel Production. NANOMATERIALS (BASEL, SWITZERLAND) 2022; 12:4022. [PMID: 36432308 PMCID: PMC9696162 DOI: 10.3390/nano12224022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/11/2022] [Revised: 11/11/2022] [Accepted: 11/12/2022] [Indexed: 06/16/2023]
Abstract
Here, a composite nanoparticle with an acid-base bifunctional structure has been reported for the transesterification of rapeseed oil to produce biodiesel. Triazole-PWA (PWA = 12-tungstophosphoric acid) composite materials with a hexahedral structure are produced using the precipitation method, showing the average particle diameters of 200-800 nm. XPS and FT-IR analyses indicate well-defined chemical bonding of triazole moieties to the PWA. The functionalization and immobilization of PWAs are investigated due to strong interactions with triazole, which significantly improves the thermal stability and even surface area of the heteropoly acid. Furthermore, various ratios of triazole and PWAs are examined using NH3-TPD and CO2-TPD to optimize the bi-functionality of acidity and basicity. The prepared nanomaterials are evaluated during the transesterification of rapeseed oil with methanol to analyze the effect of triazole addition to PWAs according to the different ratios. Overall, the bifunctional triazole-PWA composite nanoparticles exhibit higher fatty acid methyl ester (FAME) conversions than pure PWA nanoparticles. The optimized catalyst with a triazole:PWA ratio of 6:1 exhibits the best FAME-conversion performance due to its relatively large surface area, balance of acidity, and strong basicity from the well-designed chemical nano-structure.
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Affiliation(s)
- Gicheon Lee
- Department of Chemical and Biomolecular Engineering, Yonsei University, Yonsei-ro 50, Seodaemun-gu, Seoul 120-749, Republic of Korea
- Green and Sustainable Materials R&D Department, Korea Institute of Industrial Technology, 89 Yangdaegiro-gil, Ipjan-myeon, Seobuk-gu, Cheonan-si 31056, Chungcheongnam-do, Republic of Korea
| | - Chanmin Lee
- Green and Sustainable Materials R&D Department, Korea Institute of Industrial Technology, 89 Yangdaegiro-gil, Ipjan-myeon, Seobuk-gu, Cheonan-si 31056, Chungcheongnam-do, Republic of Korea
| | - Hyungjin Kim
- Department of Environmental and Energy Engineering, Yonsei University, 1 Yonseidae-gil, Wonju 26493, Republic of Korea
| | - Yukwon Jeon
- Department of Environmental and Energy Engineering, Yonsei University, 1 Yonseidae-gil, Wonju 26493, Republic of Korea
| | - Yong-Gun Shul
- Department of Chemical and Biomolecular Engineering, Yonsei University, Yonsei-ro 50, Seodaemun-gu, Seoul 120-749, Republic of Korea
| | - Jinwon Park
- Department of Chemical and Biomolecular Engineering, Yonsei University, Yonsei-ro 50, Seodaemun-gu, Seoul 120-749, Republic of Korea
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9
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Wearable Sensors for Healthcare: Fabrication to Application. SENSORS 2022; 22:s22145137. [PMID: 35890817 PMCID: PMC9323732 DOI: 10.3390/s22145137] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/31/2022] [Revised: 07/06/2022] [Accepted: 07/06/2022] [Indexed: 02/07/2023]
Abstract
This paper presents a substantial review of the deployment of wearable sensors for healthcare applications. Wearable sensors hold a pivotal position in the microelectronics industry due to their role in monitoring physiological movements and signals. Sensors designed and developed using a wide range of fabrication techniques have been integrated with communication modules for transceiving signals. This paper highlights the entire chronology of wearable sensors in the biomedical sector, starting from their fabrication in a controlled environment to their integration with signal-conditioning circuits for application purposes. It also highlights sensing products that are currently available on the market for a comparative study of their performances. The conjugation of the sensing prototypes with the Internet of Things (IoT) for forming fully functioning sensorized systems is also shown here. Finally, some of the challenges existing within the current wearable systems are shown, along with possible remedies.
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10
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Recent Advances in Electronic Skins with Multiple-Stimuli-Responsive and Self-Healing Abilities. MATERIALS 2022; 15:ma15051661. [PMID: 35268894 PMCID: PMC8911295 DOI: 10.3390/ma15051661] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/20/2021] [Revised: 01/31/2022] [Accepted: 02/04/2022] [Indexed: 02/01/2023]
Abstract
Wearable electronic skin (e-skin) has provided a revolutionized way to intelligently sense environmental stimuli, which shows prospective applications in health monitoring, artificial intelligence and prosthetics fields. Drawn inspiration from biological skins, developing e-skin with multiple stimuli perception and self-healing abilities not only enrich their bionic multifunctionality, but also greatly improve their sensory performance and functional stability. In this review, we highlight recent important developments in the material structure design strategy to imitate the fascinating functionalities of biological skins, including molecular synthesis, physical structure design, and special biomimicry engineering. Moreover, their specific structure-property relationships, multifunctional application, and existing challenges are also critically analyzed with representative examples. Furthermore, a summary and perspective on future directions and challenges of biomimetic electronic skins regarding function construction will be briefly discussed. We believe that this review will provide valuable guidance for readers to fabricate superior e-skin materials or devices with skin-like multifunctionalities and disparate characteristics.
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11
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Madhavan R. Network crack-based high performance stretchable strain sensors for human activity and healthcare monitoring. NEW J CHEM 2022. [DOI: 10.1039/d2nj03297j] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
In this study, high performance wearable and stretchable strain sensors are developed for human activity and healthcare monitoring, and wearable electronics.
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Affiliation(s)
- R. Madhavan
- Department of Chemical Engineering, Indian Institute of Science, Bengaluru 560012, Karnataka, India
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12
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Recent Development of Multifunctional Sensors Based on Low-Dimensional Materials. SENSORS 2021; 21:s21227727. [PMID: 34833801 PMCID: PMC8618950 DOI: 10.3390/s21227727] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/14/2021] [Revised: 11/01/2021] [Accepted: 11/10/2021] [Indexed: 12/30/2022]
Abstract
With the demand for accurately recognizing human actions and environmental situations, multifunctional sensors are essential elements for smart applications in various emerging technologies, such as smart robots, human-machine interface, and wearable electronics. Low-dimensional materials provide fertile soil for multifunction-integrated devices. This review focuses on the multifunctional sensors for mechanical stimulus and environmental information, such as strain, pressure, light, temperature, and gas, which are fabricated from low-dimensional materials. The material characteristics, device architecture, transmission mechanisms, and sensing functions are comprehensively and systematically introduced. Besides multiple sensing functions, the integrated potential ability of supplying energy and expressing and storing information are also demonstrated. Some new process technologies and emerging research areas are highlighted. It is presented that optimization of device structures, appropriate material selection for synergy effect, and application of piezotronics and piezo-phototronics are effective approaches for constructing and improving the performance of multifunctional sensors. Finally, the current challenges and direction of future development are proposed.
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13
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Zhang F, Ma PC, Wang J, Zhang Q, Feng W, Zhu Y, Zheng Q. Anisotropic conductive networks for multidimensional sensing. MATERIALS HORIZONS 2021; 8:2615-2653. [PMID: 34617540 DOI: 10.1039/d1mh00615k] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
In the past decade, flexible physical sensors have attracted great attention due to their wide applications in many emerging areas including health-monitoring, human-machine interfaces, smart robots, and entertainment. However, conventional sensors are typically designed to respond to a specific stimulus or a deformation along only one single axis, while directional tracking and accurate monitoring of complex multi-axis stimuli is more critical in practical applications. Multidimensional sensors with distinguishable signals for simultaneous detection of complex postures and movements in multiple directions are highly demanded for the development of wearable electronics. Recently, many efforts have been devoted to the design and fabrication of multidimensional sensors that are capable of distinguishing stimuli from different directions accurately. Benefiting from their unique decoupling mechanisms, anisotropic architectures have been proved to be promising structures for multidimensional sensing. This review summarizes the present state and advances of the design and preparation strategies for fabricating multidimensional sensors based on anisotropic conducting networks. The fabrication strategies of different anisotropic structures, the working mechanism of various types of multidimensional sensing and their corresponding unique applications are presented and discussed. The potential challenges faced by multidimensional sensors are revealed to provide an insightful outlook for the future development.
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Affiliation(s)
- Fei Zhang
- School of Science and Engineering, The Chinese University of Hong Kong, Shenzhen, Shenzhen, Guangdong, 518172, P. R. China.
- Department of Materials Science and Engineering, University of Science and Technology of China, Hefei, Anhui, 230026, P. R. China.
| | - Peng-Cheng Ma
- Laboratory of Environmental Science and Technology, The Xinjiang Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Urumqi, 830011, P. R. China
| | - Jiangxin Wang
- School of Science and Engineering, The Chinese University of Hong Kong, Shenzhen, Shenzhen, Guangdong, 518172, P. R. China.
| | - Qi Zhang
- School of Science and Engineering, The Chinese University of Hong Kong, Shenzhen, Shenzhen, Guangdong, 518172, P. R. China.
| | - Wei Feng
- School of Materials Science and Engineering, Tianjin University, Tianjin, 300072, P. R. China.
- Key Laboratory of Materials Processing and Mold, Ministry of Education, Zhengzhou University, Zhengzhou, 450002, P. R. China
| | - Yanwu Zhu
- Department of Materials Science and Engineering, University of Science and Technology of China, Hefei, Anhui, 230026, P. R. China.
| | - Qingbin Zheng
- School of Science and Engineering, The Chinese University of Hong Kong, Shenzhen, Shenzhen, Guangdong, 518172, P. R. China.
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14
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Zhang W, Liu Q, Chao S, Liu R, Cui X, Sun Y, Ouyang H, Li Z. Ultrathin Stretchable Triboelectric Nanogenerators Improved by Postcharging Electrode Material. ACS APPLIED MATERIALS & INTERFACES 2021; 13:42966-42976. [PMID: 34473476 DOI: 10.1021/acsami.1c13840] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Sustainable ultrathin stretchable power sources have emerged with the development of wearable electronics. They obtain energy from living organisms and the environment to drive these wearable electronics. Here, an ultrathin stretchable and triboelectric nanogenerator (TENG) improved by chargeable carbon black (CB)/thermoplastic polyurethane (TPU) composite material (CT-TENG) is proposed for mechanical energy harvesting and physiological signal sensing. The CB/TPU composite can act as both a stretchable electrode and a triboelectric layer due to the coexistence of conductive CB and dielectric TPU. The CT-TENG demonstrates good stretchability (≈646%), ultrathin thickness (≈50 μm), and a lightweight (≈62 mg). The triboelectric electrode material can be improved by postcharging treatment. With the corona charging process, the output performance of the CT-TENG was improved eightfold and reached 41 V. Moreover, the CT-TENG with a self-powered sensing capability can inspect the amplitude and frequency of different physiological movements. Consequently, the CT-TENG is promising in promoting the development of electronic skins, wearable systems of self-powered sensors, human-machine interactions, soft robotics, and artificial intelligence applications.
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Affiliation(s)
- Weiyi Zhang
- School of Microelectronics, Tianjin University, No. 92 Weijin Road, Tianjin 300072, People's Republic of China
- CAS Center for Excellence in Nanoscience, Beijing Key Laboratory of Micro-Nano Energy and Sensor, Beijing Institute of Nanoenergy and Nanosystems, Chinese Academy of Sciences, No. 8 Yangyandongyi Road, Beijing 101400, People's Republic of China
| | - Qiang Liu
- School of Microelectronics, Tianjin University, No. 92 Weijin Road, Tianjin 300072, People's Republic of China
| | - Shengyu Chao
- CAS Center for Excellence in Nanoscience, Beijing Key Laboratory of Micro-Nano Energy and Sensor, Beijing Institute of Nanoenergy and Nanosystems, Chinese Academy of Sciences, No. 8 Yangyandongyi Road, Beijing 101400, People's Republic of China
- School of Nanoscience and Technology, University of Chinese Academy of Sciences, No.19(A) Yuquan Road, Shijingshan District, Beijing 100049, People's Republic of China
| | - Ruping Liu
- Beijing Institute of Graphic Communication, No.1 (Band-2) Xinghua Street, Daxing District, Beijing 102600, People's Republic of China
| | - Xi Cui
- CAS Center for Excellence in Nanoscience, Beijing Key Laboratory of Micro-Nano Energy and Sensor, Beijing Institute of Nanoenergy and Nanosystems, Chinese Academy of Sciences, No. 8 Yangyandongyi Road, Beijing 101400, People's Republic of China
- School of Nanoscience and Technology, University of Chinese Academy of Sciences, No.19(A) Yuquan Road, Shijingshan District, Beijing 100049, People's Republic of China
| | - Yu Sun
- CAS Center for Excellence in Nanoscience, Beijing Key Laboratory of Micro-Nano Energy and Sensor, Beijing Institute of Nanoenergy and Nanosystems, Chinese Academy of Sciences, No. 8 Yangyandongyi Road, Beijing 101400, People's Republic of China
| | - Han Ouyang
- School of Nanoscience and Technology, University of Chinese Academy of Sciences, No.19(A) Yuquan Road, Shijingshan District, Beijing 100049, People's Republic of China
- Key Laboratory for Biomechanics and Mechanobiology of Chinese Education Ministry, Beijing Advanced Innovation Centre for Biomedical Engineering, School of Biological Science and Medical Engineering, Beihang University, No. 37 Xueyuan Road, Haidian District, Beijing 100083, People's Republic of China
| | - Zhou Li
- CAS Center for Excellence in Nanoscience, Beijing Key Laboratory of Micro-Nano Energy and Sensor, Beijing Institute of Nanoenergy and Nanosystems, Chinese Academy of Sciences, No. 8 Yangyandongyi Road, Beijing 101400, People's Republic of China
- School of Nanoscience and Technology, University of Chinese Academy of Sciences, No.19(A) Yuquan Road, Shijingshan District, Beijing 100049, People's Republic of China
- Center on Nanoenergy Research School of Physical Science and Technology, Guangxi University, No. 100, East University Road, Nanning 530004, People's Republic of China
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15
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Han F, Li M, Ye H, Zhang G. Materials, Electrical Performance, Mechanisms, Applications, and Manufacturing Approaches for Flexible Strain Sensors. NANOMATERIALS (BASEL, SWITZERLAND) 2021; 11:1220. [PMID: 34063165 PMCID: PMC8148098 DOI: 10.3390/nano11051220] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/19/2021] [Revised: 04/30/2021] [Accepted: 05/01/2021] [Indexed: 12/13/2022]
Abstract
With the recent great progress made in flexible and wearable electronic materials, the upcoming next generation of skin-mountable and implantable smart devices holds extensive potential applications for the lifestyle modifying, including personalized health monitoring, human-machine interfaces, soft robots, and implantable biomedical devices. As a core member within the wearable electronics family, flexible strain sensors play an essential role in the structure design and functional optimization. To further enhance the stretchability, flexibility, sensitivity, and electricity performances of the flexible strain sensors, enormous efforts have been done covering the materials design, manufacturing approaches and various applications. Thus, this review summarizes the latest advances in flexible strain sensors over recent years from the material, application, and manufacturing strategies. Firstly, the critical parameters measuring the performances of flexible strain sensors and materials development contains different flexible substrates, new nano- and hybrid- materials are introduced. Then, the developed working mechanisms, theoretical analysis, and computational simulation are presented. Next, based on different material design, diverse applications including human motion detection and health monitoring, soft robotics and human-machine interface, implantable devices, and biomedical applications are highlighted. Finally, synthesis consideration of the massive production industry of flexible strain sensors in the future; different fabrication approaches that are fully expected are classified and discussed.
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Affiliation(s)
- Fei Han
- Institute of Future Lighting, Academy for Engineering and Technology, Fudan University, Shanghai 200433, China; (F.H.); (M.L.)
- Shenzhen Institute of Wide-Bandgap Semiconductors, Shenzhen 518055, China
| | - Min Li
- Institute of Future Lighting, Academy for Engineering and Technology, Fudan University, Shanghai 200433, China; (F.H.); (M.L.)
| | - Huaiyu Ye
- Shenzhen Institute of Wide-Bandgap Semiconductors, Shenzhen 518055, China
| | - Guoqi Zhang
- Institute of Future Lighting, Academy for Engineering and Technology, Fudan University, Shanghai 200433, China; (F.H.); (M.L.)
- Shenzhen Institute of Wide-Bandgap Semiconductors, Shenzhen 518055, China
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16
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Aslanidis E, Skotadis E, Tsoukalas D. Resistive crack-based nanoparticle strain sensors with extreme sensitivity and adjustable gauge factor, made on flexible substrates. NANOSCALE 2021; 13:3263-3274. [PMID: 33533788 DOI: 10.1039/d0nr07002e] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
In this paper, we report the demonstration of highly sensitive flexible strain sensors formed by a network of metallic nanoparticles (NPs) grown under vacuum on top of a cracked thin alumina film which has been deposited by atomic layer deposition. It is shown that the sensor sensitivity depends on the surface density of NPs as well as on the thickness of alumina thin films that can both be well controlled via the deposition techniques. This method allows reaching a record strain sensitivity value of 2.6 × 108 at 7.2% strain, while exhibiting high sensitivity in a large strain range from 0.1% to 7.2%. The demonstration is followed by a discussion enlightening the physical understanding of sensor operation, which enables the tuning of its performance according to the above process parameters.
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Affiliation(s)
- Evangelos Aslanidis
- Department of Applied Physics, National Technical University of Athens, Athens, 15780, Greece.
| | - Evangelos Skotadis
- Department of Applied Physics, National Technical University of Athens, Athens, 15780, Greece.
| | - Dimitris Tsoukalas
- Department of Applied Physics, National Technical University of Athens, Athens, 15780, Greece.
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17
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Nag A, Alahi MEE, Mukhopadhyay SC, Liu Z. Multi-Walled Carbon Nanotubes-Based Sensors for Strain Sensing Applications. SENSORS (BASEL, SWITZERLAND) 2021; 21:1261. [PMID: 33578782 PMCID: PMC7916448 DOI: 10.3390/s21041261] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/10/2021] [Revised: 01/22/2021] [Accepted: 02/03/2021] [Indexed: 12/28/2022]
Abstract
The use of multi-walled carbon nanotube (MWCNT)-based sensors for strain-strain applications is showcased in this paper. Extensive use of MWCNTs has been done for the fabrication and implementation of flexible sensors due to their enhanced electrical, mechanical, and thermal properties. These nanotubes have been deployed both in pure and composite forms for obtaining highly efficient sensors in terms of sensitivity, robustness, and longevity. Among the wide range of applications that MWCNTs have been exploited for, strain-sensing has been one of the most popular ones due to the high mechanical flexibility of these carbon allotropes. The MWCNT-based sensors have been able to deduce a broad spectrum of macro- and micro-scaled tensions through structural changes. This paper highlights some of the well-approved conjugations of MWCNTs with different kinds of polymers and other conductive nanomaterials to form the electrodes of the strain sensors. It also underlines some of the measures that can be taken in the future to improve the quality of these MWCNT-based sensors for strain-related applications.
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Affiliation(s)
- Anindya Nag
- School of Information Science and Engineering, Shandong University, Jinan 251600, China;
| | - Md. Eshrat E Alahi
- The Institute of Biomedical and Health Engineering, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055, China;
| | | | - Zhi Liu
- School of Information Science and Engineering, Shandong University, Jinan 251600, China;
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18
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Abstract
The development of wearable sensors is aimed at enabling continuous real-time health monitoring, which leads to timely and precise diagnosis anytime and anywhere. Unlike conventional wearable sensors that are somewhat bulky, rigid, and planar, research for next-generation wearable sensors has been focused on establishing fully-wearable systems. To attain such excellent wearability while providing accurate and reliable measurements, fabrication strategies should include (1) proper choices of materials and structural designs, (2) constructing efficient wireless power and data transmission systems, and (3) developing highly-integrated sensing systems. Herein, we discuss recent advances in wearable devices for non-invasive sensing, with focuses on materials design, nano/microfabrication, sensors, wireless technologies, and the integration of those.
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19
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Kanoun O, Bouhamed A, Ramalingame R, Bautista-Quijano JR, Rajendran D, Al-Hamry A. Review on Conductive Polymer/CNTs Nanocomposites Based Flexible and Stretchable Strain and Pressure Sensors. SENSORS (BASEL, SWITZERLAND) 2021; 21:E341. [PMID: 33419047 PMCID: PMC7825437 DOI: 10.3390/s21020341] [Citation(s) in RCA: 47] [Impact Index Per Article: 15.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/25/2020] [Revised: 12/20/2020] [Accepted: 01/01/2021] [Indexed: 01/15/2023]
Abstract
In the last decade, significant developments of flexible and stretchable force sensors have been witnessed in order to satisfy the demand of several applications in robotic, prosthetics, wearables and structural health monitoring bringing decisive advantages due to their manifold customizability, easy integration and outstanding performance in terms of sensor properties and low-cost realization. In this paper, we review current advances in this field with a special focus on polymer/carbon nanotubes (CNTs) based sensors. Based on the electrical properties of polymer/CNTs nanocomposite, we explain underlying principles for pressure and strain sensors. We highlight the influence of the manufacturing processes on the achieved sensing properties and the manifold possibilities to realize sensors using different shapes, dimensions and measurement procedures. After an intensive review of the realized sensor performances in terms of sensitivity, stretchability, stability and durability, we describe perspectives and provide novel trends for future developments in this intriguing field.
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Affiliation(s)
- Olfa Kanoun
- Professorship of Measurement and Sensor Technology, Chemnitz University of Technology, 09111 Chemnitz, Germany; (R.R.); (J.R.B.-Q.); (D.R.); (A.A.-H.)
| | - Ayda Bouhamed
- Professorship of Measurement and Sensor Technology, Chemnitz University of Technology, 09111 Chemnitz, Germany; (R.R.); (J.R.B.-Q.); (D.R.); (A.A.-H.)
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20
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Printability of the Screen-Printed Strain Sensor with Carbon Black/Silver Paste for Sensitive Wearable Electronics. APPLIED SCIENCES-BASEL 2020. [DOI: 10.3390/app10196983] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Printing technology enables not only high-volume, multipurpose, low-impact, low-cost manufacturing, but also the introduction of flexible electronic devices, such as displays, actuators, and sensors, to a wide range of consumer markets. Consequently, in the past few decades, printed electronic products have attracted considerable interest. Although flexible printed electronic products are attracting increasing attention from the scientific and industrial communities, a systematic study on their sensing performance based on printability has not been reported so far. In this study, carbon black/Ag nanocomposites were utilized as pastes for a flexible wearable strain sensor. The effects of the rheological property of the pastes and the pattern dimensions of the printed electrodes on the sensor’s performance were investigated. Consequently, the printed sensor demonstrated a high gauge factor of 444.5 for an applied strain of 0.6% to 1.4% with a durability of 1000 cycles and a linearity of R2 = 0.9974. The sensor was also stable under tough environmental conditions.
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21
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Losaria PM, Yim J. Enhancement of Strain‐Sensing Performance through Gas Phase Incorporation of Siloxane into Thermoplastic Polyurethane‐Conducting Polymer Composite. MACROMOL CHEM PHYS 2020. [DOI: 10.1002/macp.202000155] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Affiliation(s)
- Pauline May Losaria
- Division of Advanced Materials EngineeringKongju National University Budaedong 275, Seobuk‐gu Cheonan‐si Chungnam 31080 South Korea
| | - Jin‐Heong Yim
- Division of Advanced Materials EngineeringKongju National University Budaedong 275, Seobuk‐gu Cheonan‐si Chungnam 31080 South Korea
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22
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Forró C, Ihle SJ, Reichmuth AM, Han H, Stauffer F, Weaver S, Bonnin A, Stampanoni M, Tybrandt K, Vörös J. Visualizing and Analyzing 3D Metal Nanowire Networks for Stretchable Electronics. ADVANCED THEORY AND SIMULATIONS 2020. [DOI: 10.1002/adts.202000038] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Affiliation(s)
- Csaba Forró
- Institute for Biomedical EngineeringUniversity and ETH ZurichZurich 8092 Switzerland
| | - Stephan J. Ihle
- Institute for Biomedical EngineeringUniversity and ETH ZurichZurich 8092 Switzerland
| | - Andreas M. Reichmuth
- Institute for Biomedical EngineeringUniversity and ETH ZurichZurich 8092 Switzerland
| | - Hana Han
- Institute for Biomedical EngineeringUniversity and ETH ZurichZurich 8092 Switzerland
| | - Flurin Stauffer
- Institute for Biomedical EngineeringUniversity and ETH ZurichZurich 8092 Switzerland
| | - Sean Weaver
- Institute for Biomedical EngineeringUniversity and ETH ZurichZurich 8092 Switzerland
| | - Anne Bonnin
- Paul Scherrer Inst, Swiss Light SourceVilligen CH‐5232 Switzerland
| | - Marco Stampanoni
- Institute for Biomedical EngineeringUniversity and ETH ZurichZurich 8092 Switzerland
- Paul Scherrer Inst, Swiss Light SourceVilligen CH‐5232 Switzerland
| | - Klas Tybrandt
- Laboratory of Organic ElectronicsDepartment of Science and TechnologyLinköping UniversityNorrköping 601 74 Sweden
| | - János Vörös
- Institute for Biomedical EngineeringUniversity and ETH ZurichZurich 8092 Switzerland
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23
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Aslanidis E, Skotadis E, Moutoulas E, Tsoukalas D. Thin Film Protected Flexible Nanoparticle Strain Sensors: Experiments and Modeling. SENSORS (BASEL, SWITZERLAND) 2020; 20:s20092584. [PMID: 32370042 PMCID: PMC7248731 DOI: 10.3390/s20092584] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/21/2020] [Revised: 04/25/2020] [Accepted: 04/29/2020] [Indexed: 06/11/2023]
Abstract
In this work, the working performance of Platinum (Pt), solvent-free nanoparticle (NP)-based strain sensors made on a flexible substrate has been studied. First, a new model has been developed in order to explain sensor behaviour under strain in a more effective manner than what has been previously reported. The proposed model also highlights the difference between sensors based on solvent-free and solvent-based NPs. As a second step, the ability of atomic layer deposition (ALD) developed Al2O3 (alumina) thin films to act as protective coatings against humidity while in adverse conditions (i.e., variations in relative humidity and repeated mechanical stress) has been evaluated. Two different alumina thicknesses (5 and 11 nm) have been tested and their effect on protection against humidity is studied by monitoring sensor resistance. Even in the case of adverse working conditions and for increased mechanical strain (up to 1.2%), it is found that an alumina layer of 11 nm provides sufficient sensor protection, while the proposed model remains valid. This certifies the appropriateness of the proposed strain-sensing technology for demanding applications, such as e-skin and pressure or flow sensing, as well as the possibility of developing a comprehensive computational tool for NP-based devices.
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Affiliation(s)
- Evangelos Aslanidis
- Department of Applied Physics, National Technical University of Athens, 15780 Athens, Greece; (E.S.); (E.M.); (D.T.)
| | - Evangelos Skotadis
- Department of Applied Physics, National Technical University of Athens, 15780 Athens, Greece; (E.S.); (E.M.); (D.T.)
| | - Evangelos Moutoulas
- Department of Applied Physics, National Technical University of Athens, 15780 Athens, Greece; (E.S.); (E.M.); (D.T.)
- Centre for Electronics Frontiers Zepler, Institute for Photonics and Nanoelectronics, University of Southampton Highfield Campus, University Road, Building 53 (Mountbatten), Southampton SO17 1BJ, UK
| | - Dimitris Tsoukalas
- Department of Applied Physics, National Technical University of Athens, 15780 Athens, Greece; (E.S.); (E.M.); (D.T.)
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24
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Gao Y, Yu L, Yeo JC, Lim CT. Flexible Hybrid Sensors for Health Monitoring: Materials and Mechanisms to Render Wearability. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2020; 32:e1902133. [PMID: 31339200 DOI: 10.1002/adma.201902133] [Citation(s) in RCA: 114] [Impact Index Per Article: 28.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/03/2019] [Revised: 05/03/2019] [Indexed: 05/19/2023]
Abstract
Wearable electronics have revolutionized the way physiological parameters are sensed, detected, and monitored. In recent years, advances in flexible and stretchable hybrid electronics have created emergent properties that enhance the compliance of devices to our skin. With their unobtrusive attributes, skin conformable sensors enable applications toward real-time disease diagnosis and continuous healthcare monitoring. Herein, critical perspectives of flexible hybrid electronics toward the future of digital health monitoring are provided, emphasizing its role in physiological sensing. In particular, the strategies within the sensor composition to render flexibility and stretchability while maintaining excellent sensing performance are considered. Next, novel approaches to the functionalization of the sensor for physical or biochemical stimuli are extensively covered. Subsequently, wearable sensors measuring physical parameters such as strain, pressure, temperature, as well as biological changes in metabolites and electrolytes are reported. Finally, their implications toward early disease detection and monitoring are discussed, concluding with a future perspective into the challenges and opportunities in emerging wearable sensor designs for the next few years.
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Affiliation(s)
- Yuji Gao
- Department of Biomedical Engineering, National University of Singapore, Singapore, 117583, Singapore
| | - Longteng Yu
- Department of Biomedical Engineering, National University of Singapore, Singapore, 117583, Singapore
| | - Joo Chuan Yeo
- Institute for Health Innovation and Technology (iHealthtech), National University of Singapore, Singapore, 117599, Singapore
| | - Chwee Teck Lim
- Department of Biomedical Engineering, National University of Singapore, Singapore, 117583, Singapore
- Institute for Health Innovation and Technology (iHealthtech), National University of Singapore, Singapore, 117599, Singapore
- Mechanobiology Institute, National University of Singapore, Singapore, 117411, Singapore
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25
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Yu L, Feng Y, S/O M Tamil Selven D, Yao L, Soon RH, Yeo JC, Lim CT. Dual-Core Capacitive Microfiber Sensor for Smart Textile Applications. ACS APPLIED MATERIALS & INTERFACES 2019; 11:33347-33355. [PMID: 31424908 DOI: 10.1021/acsami.9b10937] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Wearable sensors for smart textile applications have garnered tremendous interest in recent years and can have enormous potential for human machine interfaces and digital health monitoring. Here, we report a soft capacitive microfiber sensor that can be woven seamlessly into textiles for strain measurement. Comprising a dual-lumen elastomeric microtube and liquid metallic alloy, the microfiber sensor enables continual strain perception even after being completely severed. In addition, our microfiber sensor is highly stretchable and flexible and exhibits tunable sensitivity, excellent linearity, a fast response, and negligible hysteresis. More importantly, the microfiber sensor is minimally affected by train rate and compression during strain sensing. Even under drastic environmental changes, the microfiber sensor presents good electrical stability. By integrating the microfiber sensor imperceptibly with textiles, we devise smart textile wearables to interpret hand gestures, detect limb motion, and monitor respiration rate. We believe that this sensor presents enormous potential in unobtrusive continuous health monitoring.
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Affiliation(s)
- Longteng Yu
- Department of Biomedical Engineering , National University of Singapore , Singapore 117583 , Singapore
| | - Yuqin Feng
- Department of Biomedical Engineering , National University of Singapore , Singapore 117583 , Singapore
- NUS Graduate School for Integrative Sciences and Engineering , National University of Singapore , Singapore 119077 , Singapore
| | - Dinesh S/O M Tamil Selven
- Department of Biomedical Engineering , National University of Singapore , Singapore 117583 , Singapore
| | - Liangsong Yao
- Department of Materials Science and Engineering , National University of Singapore , Singapore 117575 , Singapore
| | - Ren Hao Soon
- Department of Biomedical Engineering , National University of Singapore , Singapore 117583 , Singapore
| | - Joo Chuan Yeo
- Institute for Health Innovation and Technology , National University of Singapore , Singapore 117599 , Singapore
| | - Chwee Teck Lim
- Department of Biomedical Engineering , National University of Singapore , Singapore 117583 , Singapore
- NUS Graduate School for Integrative Sciences and Engineering , National University of Singapore , Singapore 119077 , Singapore
- Institute for Health Innovation and Technology , National University of Singapore , Singapore 117599 , Singapore
- Mechanobiology Institute , National University of Singapore , Singapore 117411 , Singapore
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26
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Raja IS, Song SJ, Kang MS, Lee YB, Kim B, Hong SW, Jeong SJ, Lee JC, Han DW. Toxicity of Zero- and One-Dimensional Carbon Nanomaterials. NANOMATERIALS (BASEL, SWITZERLAND) 2019; 9:E1214. [PMID: 31466309 PMCID: PMC6780407 DOI: 10.3390/nano9091214] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/05/2019] [Revised: 08/23/2019] [Accepted: 08/23/2019] [Indexed: 12/14/2022]
Abstract
The zero (0-D) and one-dimensional (1-D) carbon nanomaterials have gained attention among researchers because they exhibit a larger surface area to volume ratio, and a smaller size. Furthermore, carbon is ubiquitously present in all living organisms. However, toxicity is a major concern while utilizing carbon nanomaterials for biomedical applications such as drug delivery, biosensing, and tissue regeneration. In the present review, we have summarized some of the recent findings of cellular and animal level toxicity studies of 0-D (carbon quantum dot, graphene quantum dot, nanodiamond, and carbon black) and 1-D (single-walled and multi-walled carbon nanotubes) carbon nanomaterials. The in vitro toxicity of carbon nanomaterials was exemplified in normal and cancer cell lines including fibroblasts, osteoblasts, macrophages, epithelial and endothelial cells of different sources. Similarly, the in vivo studies were illustrated in several animal species such as rats, mice, zebrafish, planktons and, guinea pigs, at various concentrations, route of administrations and exposure of nanoparticles. In addition, we have described the unique properties and commercial usage, as well as the similarities and differences among the nanoparticles. The aim of the current review is not only to signify the importance of studying the toxicity of 0-D and 1-D carbon nanomaterials, but also to emphasize the perspectives, future challenges and possible directions in the field.
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Affiliation(s)
| | - Su-Jin Song
- Department of Cogno-Mechatronics Engineering, College of Nanoscience & Nanotechnology, Pusan National University, Busan 46241, Korea
| | - Moon Sung Kang
- Department of Cogno-Mechatronics Engineering, College of Nanoscience & Nanotechnology, Pusan National University, Busan 46241, Korea
| | - Yu Bin Lee
- Department of Cogno-Mechatronics Engineering, College of Nanoscience & Nanotechnology, Pusan National University, Busan 46241, Korea
| | - Bongju Kim
- Dental Life Science Research Institute & Clinical Translational Research Center for Dental Science, Seoul National University Dental Hospital, Seoul 03080, Korea
| | - Suck Won Hong
- Department of Cogno-Mechatronics Engineering, College of Nanoscience & Nanotechnology, Pusan National University, Busan 46241, Korea
| | - Seung Jo Jeong
- GS Medical Co., Ltd., Cheongju-si, Chungcheongbuk-do 28161, Korea
| | - Jae-Chang Lee
- Bio-Based Chemistry Research Center, Korea Research Institute of Chemical Technology, Ulsan 44429, Korea.
| | - Dong-Wook Han
- Department of Cogno-Mechatronics Engineering, College of Nanoscience & Nanotechnology, Pusan National University, Busan 46241, Korea.
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27
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Abstract
A body area network (BAN) comprises a set of devices that sense their surroundings, activate and communicate with each other when an event is detected in its environment. Although BAN technology was developed more than 20 years ago, in recent years, its popularity has greatly increased. The reason is the availability of smaller and more powerful devices, more efficient communication protocols and improved duration of portable batteries. BANs are applied in many fields, healthcare being one of the most important through gathering information about patients and their surroundings. A continuous stream of information may help physicians with making well-informed decisions about a patient’s treatment. Based on recent literature, the authors review BAN architectures, network topologies, energy sources, sensor types, applications, as well as their main challenges. In addition, the paper focuses on the principal requirements of safety, security, and sustainability. In addition, future research and improvements are discussed.
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Efficient reduction of Toluidine Blue O dye using silver nanoparticles synthesized by low molecular weight chitosans. Int J Biol Macromol 2019; 131:682-690. [DOI: 10.1016/j.ijbiomac.2019.03.119] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2018] [Revised: 02/03/2019] [Accepted: 03/18/2019] [Indexed: 11/22/2022]
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29
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Abstract
Flexible sensors have the potential to be seamlessly applied to soft and irregularly shaped surfaces such as the human skin or textile fabrics. This benefits conformability dependant applications including smart tattoos, artificial skins and soft robotics. Consequently, materials and structures for innovative flexible sensors, as well as their integration into systems, continue to be in the spotlight of research. This review outlines the current state of flexible sensor technologies and the impact of material developments on this field. Special attention is given to strain, temperature, chemical, light and electropotential sensors, as well as their respective applications.
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