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Haghgoo M, Ansari R, Hassanzadeh-Aghdam MK, Jamali J. A subbands study on the resistivity of field-effect CNT-based piezoresistive nanocomposites. NANOTECHNOLOGY 2024; 35:325704. [PMID: 38740007 DOI: 10.1088/1361-6528/ad4a7d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/29/2024] [Accepted: 05/13/2024] [Indexed: 05/16/2024]
Abstract
In this paper, an analytical model based on the percolation theory has been developed to predict the subbands effect on the effective electrical resistivity of carbon nanotubes (CNT)-based polymer nanocomposites. The CNTs are considered as randomly distributed or aligned channel material in the polymer transmitting electrons through tunneling. The tunneling effect takes into account the electron transmission between each connected pair of CNTs to evaluate electrical resistivity. The modeling approach contains two steps of primary prediction of resistivity and further calculation of CNTs' displacements and subsequent change of the resistance. A good agreement is found between the analytical model predictions and experimental data when the tunneling behavior was considered in the percolation transition region. The effect of CNT diameter, orientation state, and subbands on the resistivity has been investigated. The results depict that subbands increment is a collateral benefit to the aspect ratio in decreasing the resistivity. The analytical results demonstrate that a random CNT dispersion leads to a decreased piezoresistivity, while an increased strain range depicts a more non-linear behavior.
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Affiliation(s)
- Mojtaba Haghgoo
- Faculty of Mechanical Engineering, University of Guilan, Rasht, Iran
| | - Reza Ansari
- Faculty of Mechanical Engineering, University of Guilan, Rasht, Iran
| | - Mohammad Kazem Hassanzadeh-Aghdam
- Department of Engineering Science, Faculty of Technology and Engineering, East of Guilan, University of Guilan, Rudsar-Vajargah, Iran
| | - Jamaloddin Jamali
- College of Engineering and Technology, American University of the Middle East, Egaila 54200, Kuwait
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2
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Gallet A, Rigby S, Tallman TN, Kong X, Hajirasouliha I, Liew A, Liu D, Chen L, Hauptmann A, Smyl D. Structural engineering from an inverse problems perspective. Proc Math Phys Eng Sci 2022; 478:20210526. [PMID: 35153609 PMCID: PMC8791046 DOI: 10.1098/rspa.2021.0526] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2021] [Accepted: 12/07/2021] [Indexed: 01/16/2023] Open
Abstract
The field of structural engineering is vast, spanning areas from the design of new infrastructure to the assessment of existing infrastructure. From the onset, traditional entry-level university courses teach students to analyse structural responses given data including external forces, geometry, member sizes, restraint, etc.-characterizing a forward problem (structural causalities → structural response). Shortly thereafter, junior engineers are introduced to structural design where they aim to, for example, select an appropriate structural form for members based on design criteria, which is the inverse of what they previously learned. Similar inverse realizations also hold true in structural health monitoring and a number of structural engineering sub-fields (response → structural causalities). In this light, we aim to demonstrate that many structural engineering sub-fields may be fundamentally or partially viewed as inverse problems and thus benefit via the rich and established methodologies from the inverse problems community. To this end, we conclude that the future of inverse problems in structural engineering is inexorably linked to engineering education and machine learning developments.
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Affiliation(s)
- A. Gallet
- Department of Civil and Structural Engineering, University of Sheffield, Sheffield, UK
| | - S. Rigby
- Department of Civil and Structural Engineering, University of Sheffield, Sheffield, UK
| | - T. N. Tallman
- School of Aeronautics and Astronautics, Purdue University, West Lafayette, IN, USA
| | - X. Kong
- Department of Physics and Engineering Science, Coastal Carolina University, Conway, SC, USA
| | - I. Hajirasouliha
- Department of Civil and Structural Engineering, University of Sheffield, Sheffield, UK
| | - A. Liew
- Department of Civil and Structural Engineering, University of Sheffield, Sheffield, UK
| | - D. Liu
- School of Physical Sciences, University of Science and Technology of China, Hefei, People’s Republic of China
| | - L. Chen
- Department of Civil and Structural Engineering, University of Sheffield, Sheffield, UK
| | - A. Hauptmann
- Research Unit of Mathematical Sciences, University of Oulu, Oulu, Finland
- Department of Computer Science, University College London, London, UK
| | - D. Smyl
- Department of Civil, Coastal, and Environmental Engineering, University of South Alabama, Mobile, AL, USA
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Coupette F, Zhang L, Kuttich B, Chumakov A, Roth SV, González-García L, Kraus T, Schilling T. Percolation of rigid fractal carbon black aggregates. J Chem Phys 2021; 155:124902. [PMID: 34598569 DOI: 10.1063/5.0058503] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
We examine network formation and percolation of carbon black by means of Monte Carlo simulations and experiments. In the simulation, we model carbon black by rigid aggregates of impenetrable spheres, which we obtain by diffusion-limited aggregation. To determine the input parameters for the simulation, we experimentally characterize the micro-structure and size distribution of carbon black aggregates. We then simulate suspensions of aggregates and determine the percolation threshold as a function of the aggregate size distribution. We observe a quasi-universal relation between the percolation threshold and a weighted average radius of gyration of the aggregate ensemble. Higher order moments of the size distribution do not have an effect on the percolation threshold. We conclude further that the concentration of large carbon black aggregates has a stronger influence on the percolation threshold than the concentration of small aggregates. In the experiment, we disperse the carbon black in a polymer matrix and measure the conductivity of the composite. We successfully test the hypotheses drawn from simulation by comparing composites prepared with the same type of carbon black before and after ball milling, i.e., on changing only the distribution of aggregate sizes in the composites.
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Affiliation(s)
- Fabian Coupette
- Institute of Physics, University of Freiburg, Hermann-Herder-Straße 3, 79104 Freiburg, Germany
| | - Long Zhang
- INM-Leibniz Institute for New Materials, Campus D2 2, 66123 Saarbrücken, Germany
| | - Björn Kuttich
- INM-Leibniz Institute for New Materials, Campus D2 2, 66123 Saarbrücken, Germany
| | - Andrei Chumakov
- Deutsches Elektronen-Synchrotron DESY, Notkestr. 85, D-22607 Hamburg, Germany
| | - Stephan V Roth
- Deutsches Elektronen-Synchrotron DESY, Notkestr. 85, D-22607 Hamburg, Germany
| | - Lola González-García
- INM-Leibniz Institute for New Materials, Campus D2 2, 66123 Saarbrücken, Germany
| | - Tobias Kraus
- INM-Leibniz Institute for New Materials, Campus D2 2, 66123 Saarbrücken, Germany
| | - Tanja Schilling
- Institute of Physics, University of Freiburg, Hermann-Herder-Straße 3, 79104 Freiburg, Germany
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Rosenburg F, Balke B, Nicoloso N, Riedel R, Ionescu E. Effect of the Content and Ordering of the sp 2 Free Carbon Phase on the Charge Carrier Transport in Polymer-Derived Silicon Oxycarbides. Molecules 2020; 25:E5919. [PMID: 33327541 PMCID: PMC7765033 DOI: 10.3390/molecules25245919] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2020] [Revised: 12/09/2020] [Accepted: 12/11/2020] [Indexed: 11/16/2022] Open
Abstract
The present work elaborates on the correlation between the amount and ordering of the free carbon phase in silicon oxycarbides and their charge carrier transport behavior. Thus, silicon oxycarbides possessing free carbon contents from 0 to ca. 58 vol.% (SiOC/C) were synthesized and exposed to temperatures from 1100 to 1800 °C. The prepared samples were extensively analyzed concerning the thermal evolution of the sp2 carbon phase by means of Raman spectroscopy. Additionally, electrical conductivity and Hall measurements were performed and correlated with the structural information obtained from the Raman spectroscopic investigation. It is shown that the percolation threshold in SiOC/C samples depends on the temperature of their thermal treatment, varying from ca. 20 vol.% in the samples prepared at 1100 °C to ca. 6 vol.% for the samples annealed at 1600 °C. Moreover, three different conduction regimes are identified in SiOC/C, depending on its sp2 carbon content: (i) at low carbon contents (i.e., <1 vol.%), the silicon oxycarbide glassy matrix dominates the charge carrier transport, which exhibits an activation energy of ca. 1 eV and occurs within localized states, presumably dangling bonds; (ii) near the percolation threshold, tunneling or hopping of charge carriers between spatially separated sp2 carbon precipitates appear to be responsible for the electrical conductivity; (iii) whereas above the percolation threshold, the charge carrier transport is only weakly activated (Ea = 0.03 eV) and is realized through the (continuous) carbon phase. Hall measurements on SiOC/C samples above the percolation threshold indicate p-type carriers mainly contributing to conduction. Their density is shown to vary with the sp2 carbon content in the range from 1014 to 1019 cm-3; whereas their mobility (ca. 3 cm2/V) seems to not depend on the sp2 carbon content.
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Affiliation(s)
- Felix Rosenburg
- Institut für Material- und Geowissenschaften, Technische Universität Darmstadt, Otto-Berndt-Straße 3, 64287 Darmstadt, Germany; (F.R.); (N.N.); (R.R.)
| | - Benjamin Balke
- Institut für Anorganische Chemie und Analytische Chemie, Johannes-Gutenberg-Universität Mainz, Duesbergweg 10-14, 55128 Mainz, Germany;
- Fraunhofer Research Institution for Materials Recycling and Resource Strategies IWKS, Rodenbacher Chaussee 4, 63457 Hanau, Germany
| | - Norbert Nicoloso
- Institut für Material- und Geowissenschaften, Technische Universität Darmstadt, Otto-Berndt-Straße 3, 64287 Darmstadt, Germany; (F.R.); (N.N.); (R.R.)
| | - Ralf Riedel
- Institut für Material- und Geowissenschaften, Technische Universität Darmstadt, Otto-Berndt-Straße 3, 64287 Darmstadt, Germany; (F.R.); (N.N.); (R.R.)
| | - Emanuel Ionescu
- Institut für Material- und Geowissenschaften, Technische Universität Darmstadt, Otto-Berndt-Straße 3, 64287 Darmstadt, Germany; (F.R.); (N.N.); (R.R.)
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Pan C, Ohm Y, Wang J, Ford MJ, Kumar K, Kumar S, Majidi C. Silver-Coated Poly(dimethylsiloxane) Beads for Soft, Stretchable, and Thermally Stable Conductive Elastomer Composites. ACS APPLIED MATERIALS & INTERFACES 2019; 11:42561-42570. [PMID: 31638761 DOI: 10.1021/acsami.9b13266] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
We introduce an elastomer composite filled with silver (Ag) flakes and Ag-coated poly(dimethylsiloxane) (PDMS) beads that exhibits electrical conductivity that is 2 orders of magnitude greater than that of elastomers in which the same concentration of Ag filler is uniformly dispersed. In addition to the dramatic enhancement in conductivity, these composites exhibit high mechanical compliance (strain limit, >100%) and robust thermal stability (conductivity change, <10% at 150 °C). The incorporation of Ag-coated PDMS beads introduces an effective phase segregation in which Ag flakes are confined to the "grain boundaries" between the embedded beads. This morphological control aids in the percolation of the Ag flakes and the formation of conductive bridges between neighboring Ag shells. The confinement of Ag flakes also suppresses thermal expansion and changes in electrical conductivity of the percolating networks when the composite is heated. We demonstrate potential applications of thermally stable elastic conductors in wearable devices and soft robotics by fabricating a highly stretchable antenna for a "smart" furnace glove and a strain sensor for soft gripper operation in hot water.
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Zhao L, Qiang F, Dai SW, Shen SC, Huang YZ, Huang NJ, Zhang GD, Guan LZ, Gao JF, Song YH, Tang LC. Construction of sandwich-like porous structure of graphene-coated foam composites for ultrasensitive and flexible pressure sensors. NANOSCALE 2019; 11:10229-10238. [PMID: 31049502 DOI: 10.1039/c9nr02672j] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
Ultrasensitive and flexible pressure sensors that can perceive and respond to environmental stimuli have attracted considerable attention due to their potential applications in wearable electronics and electronic skin devices. Here, we report a simple and low-cost strategy to fabricate high-performance pressure sensors via constructing a unique conductive/insulating/conductive sandwich-like porous structure (SPS). Interpenetration of the conductive graphene network throughout the porous insulating interlayer produces a highly efficient transition from the non-conductive to the conductive state. Consequently, the SPS sensors exhibit an extreme resistance-switching behavior (resistance change of >105 at 30 kPa), high sensitivity (∼0.67 kPa-1, <1.5 kPa), fast response/recovery time (∼10 and ∼16 ms) and outstanding mechanical stability. Such SPS pressure sensors are applicable for detecting various mechanical deformation modes (press, bend and torsion) and different stress/strain levels (from gait feature, finger/wrist/elbow movement to breathing monitoring and real-time pulse wave), providing a new concept of device design for wearable electronic applications.
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Affiliation(s)
- Li Zhao
- Key Laboratory of Organosilicon Chemistry and Material Technology of Ministry of Education, Hangzhou Normal University, Hangzhou 311121, PR China.
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Kar E, Bose N, Dutta B, Mukherjee N, Mukherjee S. Ultraviolet- and Microwave-Protecting, Self-Cleaning e-Skin for Efficient Energy Harvesting and Tactile Mechanosensing. ACS APPLIED MATERIALS & INTERFACES 2019; 11:17501-17512. [PMID: 31007019 DOI: 10.1021/acsami.9b06452] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
Smart, self-powered, and wearable e-skin that mimics the pressure sensing property of the human skin is indispensable to boost up cutting edge robotics, artificial intelligence, prosthesis, and health-care monitoring technologies. Here, fabrication of a facile and flexible hybrid piezoelectric e-skin (HPES) with multifunctions of tactile mechanosensing, energy harvesting, self-cleaning, ultraviolet (UV)-protecting, and microwave shielding properties is reported. The principal block of the HPES is an SnO2 nanosheets@SiO2 (silica-encapsulated tin oxide nanosheets)/poly(vinylidene fluoride) (PVDF) nanocomposite (SS)-based PES acting as a single unit for simultaneous energy harvesting and tactile mechanosensing. Gentle human finger imparting onto the PES showed outstanding energy conversion efficiency (16.7%) with high power density (550 W·m-3) and current density (0.40 μA·cm-2). This device can generate high enough electrical power to directly drive portable electronics like a light-emitting diode (LED) panel (consisting of 85 commercial LEDs) and to charge up capacitors very rapidly. Thin PES mechanosensors demonstrated promising performance for quantitatively detecting static and dynamic pressure stimuli with a high sensitivity of 0.99 V·kPa-1 and a short response time of 1 ms. PES was also integrated to a health-data glove for precisely monitoring and discriminating fine motions of proximal interphalangeal, metacarpophalangeal, and distal interphalangeal joints of a human finger and bending motion of different human fingers. A (4 × 4) sensing matrix of PES was successfully employed to detect the spatial distribution of static pressure stimuli. The sensing matrix can precisely record the shape and size of an object placed onto it. PES was encapsulated with a nanocomposite film for providing self-cleaning and UV and microwave protection capability to the HPES. The hydrophobic SS film wrapping (water drop contact angle ∼85.6°) of the HPES enables the self-cleaning feature and makes HPES resistive against water and dirt. The HPES was integrated with in-house-made robotic hands, and the responses of the sensors due to grabbing of an object were evaluated. This work explores new prospects for UV- and microwave-protective, self-cleaning e-skin for energy harvesting and mechanosensation, which can eventually boost up the self-powered electronics, robotics, real-time health-care monitoring, and artificial intelligence technologies.
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Affiliation(s)
| | - Navonil Bose
- Department of Physics , Supreme Knowledge Foundation Group of Institutions , Hooghly 712139 West Bengal , India
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8
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Kim SJ, Mondal S, Min BK, Choi CG. Highly Sensitive and Flexible Strain-Pressure Sensors with Cracked Paddy-Shaped MoS 2/Graphene Foam/Ecoflex Hybrid Nanostructures. ACS APPLIED MATERIALS & INTERFACES 2018; 10:36377-36384. [PMID: 30259730 DOI: 10.1021/acsami.8b11233] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
Three-dimensional graphene porous networks (GPNs) have received considerable attention as a nanomaterial for wearable touch sensor applications because of their outstanding electrical conductivity and mechanical stability. Herein, we demonstrate a strain-pressure sensor with high sensitivity and durability by combining molybdenum disulfide (MoS2) and Ecoflex with a GPN. The planar sheets of MoS2 bonded to the GPN were conformally arranged with a cracked paddy shape, and the MoS2 nanoflakes were formed on the planar sheet. The size and density of the MoS2 nanoflakes were gradually increased by raising the concentration of (NH4)2MoS4. We found that this conformal nanostructure of MoS2 on the GPN surface can produce improved resistance variation against external strain and pressure. Consequently, our MoS2/GPN/Ecoflex sensors exhibited noticeably improved sensitivity compared to previously reported GPN/polydimethylsiloxane sensors in a pressure test because of the existence of the conformal planar sheet of MoS2. In particular, the MoS2/GPN/Ecoflex sensor showed a high sensitivity of 6.06 kPa-1 at a (NH4)2MoS4 content of 1.25 wt %. At the same time, it displayed excellent durability even under repeated loading-unloading pressure and bending over 4000 cycles. When the sensor was attached on a human temple and neck, it worked correctly as a drowsiness detector in response to motion signals such as neck bending and eye blinking. Finally, a 3 × 3 tactile sensor array showed precise touch sensing capability with complete isolation of electrodes from each other for application to touch electronic applications.
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Affiliation(s)
- Seong Jun Kim
- Graphene Research Lab., Emerging Devices Research Group , Electronics and Telecommunications Research Institute (ETRI) , Daejeon 34129 , Republic of Korea
| | - Shuvra Mondal
- Graphene Research Lab., Emerging Devices Research Group , Electronics and Telecommunications Research Institute (ETRI) , Daejeon 34129 , Republic of Korea
- School of ETRI (ICT-Advanced Device Technology) , University of Science and Technology (UST) , Daejeon 34113 , Republic of Korea
| | - Bok Ki Min
- Graphene Research Lab., Emerging Devices Research Group , Electronics and Telecommunications Research Institute (ETRI) , Daejeon 34129 , Republic of Korea
| | - Choon-Gi Choi
- Graphene Research Lab., Emerging Devices Research Group , Electronics and Telecommunications Research Institute (ETRI) , Daejeon 34129 , Republic of Korea
- School of ETRI (ICT-Advanced Device Technology) , University of Science and Technology (UST) , Daejeon 34113 , Republic of Korea
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Paredes-Madrid L, Matute A, Bareño JO, Parra Vargas CA, Gutierrez Velásquez EI. Underlying Physics of Conductive Polymer Composites and Force Sensing Resistors (FSRs). A Study on Creep Response and Dynamic Loading. MATERIALS 2017; 10:ma10111334. [PMID: 29160834 PMCID: PMC5706281 DOI: 10.3390/ma10111334] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/26/2017] [Revised: 11/09/2017] [Accepted: 11/15/2017] [Indexed: 11/16/2022]
Abstract
Force Sensing Resistors (FSRs) are manufactured by sandwiching a Conductive Polymer Composite (CPC) between metal electrodes. The piezoresistive property of FSRs has been exploited to perform stress and strain measurements, but the rheological property of polymers has undermined the repeatability of measurements causing creep in the electrical resistance of FSRs. With the aim of understanding the creep phenomenon, the drift response of thirty two specimens of FSRs was studied using a statistical approach. Similarly, a theoretical model for the creep response was developed by combining the Burger's rheological model with the equations for the quantum tunneling conduction through thin insulating films. The proposed model and the experimental observations showed that the sourcing voltage has a strong influence on the creep response; this observation-and the corresponding model-is an important contribution that has not been previously accounted. The phenomenon of sensitivity degradation was also studied. It was found that sensitivity degradation is a voltage-related phenomenon that can be avoided by choosing an appropriate sourcing voltage in the driving circuit. The models and experimental observations from this study are key aspects to enhance the repeatability of measurements and the accuracy of FSRs.
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Affiliation(s)
- Leonel Paredes-Madrid
- Faculty of Electronic and Biomedical Engineering, Universidad Antonio Nariño, Tunja 150001, Colombia.
| | - Arnaldo Matute
- Faculty of Electronic and Biomedical Engineering, Universidad Antonio Nariño, Tunja 150001, Colombia.
| | - Jorge O Bareño
- Faculty of Electronic and Biomedical Engineering, Universidad Antonio Nariño, Tunja 150001, Colombia.
| | - Carlos A Parra Vargas
- Grupo de Física de Materiales (GFM), Universidad Pedagógica y Tecnológica de Colombia, Tunja 150003, Colombia.
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Wu J, Wang H, Su Z, Zhang M, Hu X, Wang Y, Wang Z, Zhong B, Zhou W, Liu J, Xing SG. Highly Flexible and Sensitive Wearable E-Skin Based on Graphite Nanoplatelet and Polyurethane Nanocomposite Films in Mass Industry Production Available. ACS APPLIED MATERIALS & INTERFACES 2017; 9:38745-38754. [PMID: 29037040 DOI: 10.1021/acsami.7b10316] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
Graphene and nanomaterials based flexible pressure sensors R&D activities are becoming hot topics due to the huge marketing demand on wearable devices and electronic skin (E-Skin) to monitor the human body's actions for dedicated healthcare. Herein, we report a facile and efficient fabrication strategy to construct a new type of highly flexible and sensitive wearable E-Skin based on graphite nanoplates (GNP) and polyurethane (PU) nanocomposite films. The developed GNP/PU E-Skin sensors are highly flexible with good electrical conductivity due to their unique binary microstructures with synergistic interfacial characteristics, which are sensitive to both static and dynamic pressure variation, and can even accurately and quickly detect the pressure as low as 0.005 N/50 Pa and momentum as low as 1.9 mN·s with a gauge factor of 0.9 at the strain variation of up to 30%. Importantly, our GNP/PU E-Skin is also highly sensitive to finger bending and stretching with a linear correlation between the relative resistance change and the corresponding bending angles or elongation percentage. In addition, our E-Skin shows excellent sensitivity to voice vibration when exposed to a volunteer's voice vibration testing. Notably, the entire E-Skin fabrication process is scalable, low cost, and industrially available. Our complementary experiments with comprehensive results demonstrate that the developed GNP/PU E-Skin is impressively promising for practical healthcare applications in wearable devices, and enables us to monitor the real-world force signals in real-time and in-situ mode from pressing, hitting, bending, stretching, and voice vibration.
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Affiliation(s)
- Jianfeng Wu
- School of Materials Science and Engineering, Harbin Institute of Technology at Weihai , 2 West Wenhua Road, Weihai 264209, China
| | - Huatao Wang
- School of Materials Science and Engineering, Harbin Institute of Technology at Weihai , 2 West Wenhua Road, Weihai 264209, China
| | - Zhiwei Su
- School of Materials Science and Engineering, Harbin Institute of Technology at Weihai , 2 West Wenhua Road, Weihai 264209, China
| | - Minghao Zhang
- School of Materials Science and Engineering, Harbin Institute of Technology at Weihai , 2 West Wenhua Road, Weihai 264209, China
| | - Xiaodong Hu
- School of Materials Science and Engineering, Harbin Institute of Technology at Weihai , 2 West Wenhua Road, Weihai 264209, China
| | - Yijie Wang
- School of Materials Science and Engineering, Harbin Institute of Technology at Weihai , 2 West Wenhua Road, Weihai 264209, China
| | - Ziao Wang
- School of Materials Science and Engineering, Harbin Institute of Technology at Weihai , 2 West Wenhua Road, Weihai 264209, China
| | - Bo Zhong
- School of Materials Science and Engineering, Harbin Institute of Technology at Weihai , 2 West Wenhua Road, Weihai 264209, China
| | - Weiwei Zhou
- School of Materials Science and Engineering, Harbin Institute of Technology at Weihai , 2 West Wenhua Road, Weihai 264209, China
| | - Junpeng Liu
- Department of Mechanical, Materials and Manufacturing Engineering, University of Nottingham , Nottingham NG7 2RD, U.K
| | - Scott Guozhong Xing
- United Microelect Corp. Ltd. , 3 Pasir Ris Dr 12, Singapore 519528, Singapore
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11
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Ke K, Pötschke P, Gao S, Voit B. An Ionic Liquid as Interface Linker for Tuning Piezoresistive Sensitivity and Toughness in Poly(vinylidene fluoride)/Carbon Nanotube Composites. ACS APPLIED MATERIALS & INTERFACES 2017; 9:5437-5446. [PMID: 28080021 DOI: 10.1021/acsami.6b13454] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Conductive polymer nanocomposites (CPNCs) have emerged as potential alternatives for metallic foil sensors and semiconductor strain gauges. The simultaneous achievement of high piezoresistive sensitivity and large strain ranges for CPNCs currently presents a great challenge and solving this challenge may extend the applications of CPNCs with self-diagnosis capabilities to many structural health-monitoring (SHM) systems. This paper reports a facile strategy for fabricating highly piezoresistive and tough poly(vinylidene fluoride) (PVDF) based CPNCs by tuning the interactions between the polymer matrix and multiwalled carbon nanotubes (CNT) using an ionic liquid (IL) as an interface linker/modifier. As a result, the presence of IL achieves homogeneous dispersion of CNTs in PVDF but causes a reduced number of CNT-CNT ohmic contacts with higher electrical contact resistance. According to the lower initial resistivity, piezoresistive sensitivity is greatly improved, and the gauge factor (GF) varies from 7 to 60 upon the addition of IL. It is also shown that IL tunes PVDF-CNT interfacial bonding and, as an effective interface linker/modifier, achieves significantly improved sensing strain ranges (increased from ca. 6 to 21%) and toughness (elongation at break increases from 6 to 130%) of CPNCs. These results substantially advance the understanding of the missing relationship between polymer-filler interface interactions and piezoresistive properties and have important implications for future studies of tuning polymer-filler interface bonding properties and piezoresistive sensitivity.
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Affiliation(s)
- Kai Ke
- Leibniz Institute of Polymer Research Dresden (IPF) , Hohe Strasse 6, 01069 Dresden Germany
- Organic Chemistry of Polymers, Technische Universität Dresden , 01062 Dresden, Germany
| | - Petra Pötschke
- Leibniz Institute of Polymer Research Dresden (IPF) , Hohe Strasse 6, 01069 Dresden Germany
| | - Shanglin Gao
- Leibniz Institute of Polymer Research Dresden (IPF) , Hohe Strasse 6, 01069 Dresden Germany
| | - Brigitte Voit
- Leibniz Institute of Polymer Research Dresden (IPF) , Hohe Strasse 6, 01069 Dresden Germany
- Organic Chemistry of Polymers, Technische Universität Dresden , 01062 Dresden, Germany
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Rinaldi A, Tamburrano A, Fortunato M, Sarto MS. A Flexible and Highly Sensitive Pressure Sensor Based on a PDMS Foam Coated with Graphene Nanoplatelets. SENSORS 2016; 16:s16122148. [PMID: 27999251 PMCID: PMC5191128 DOI: 10.3390/s16122148] [Citation(s) in RCA: 128] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/22/2016] [Revised: 11/29/2016] [Accepted: 12/08/2016] [Indexed: 01/23/2023]
Abstract
The demand for high performance multifunctional wearable devices is more and more pushing towards the development of novel low-cost, soft and flexible sensors with high sensitivity. In the present work, we describe the fabrication process and the properties of new polydimethylsiloxane (PDMS) foams loaded with multilayer graphene nanoplatelets (MLGs) for application as high sensitive piezoresistive pressure sensors. The effective DC conductivity of the produced foams is measured as a function of MLG loading. The piezoresistive response of the MLG-PDMS foam-based sensor at different strain rates is assessed through quasi-static pressure tests. The results of the experimental investigations demonstrated that sensor loaded with 0.96 wt.% of MLGs is characterized by a highly repeatable pressure-dependent conductance after a few stabilization cycles and it is suitable for detecting compressive stresses as low as 10 kPa, with a sensitivity of 0.23 kPa−1, corresponding to an applied pressure of 70 kPa. Moreover, it is estimated that the sensor is able to detect pressure variations of ~1 Pa. Therefore, the new graphene-PDMS composite foam is a lightweight cost-effective material, suitable for sensing applications in the subtle or low and medium pressure ranges.
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Affiliation(s)
- Andrea Rinaldi
- Nanotechnology Research Center Applied to Engineering (CNIS), Sapienza University of Rome, 00185 Rome, Italy.
- Department of Astronautics, Electrical and Energy Engineering (DIAEE), Sapienza University of Rome, 00184 Rome, Italy.
| | - Alessio Tamburrano
- Nanotechnology Research Center Applied to Engineering (CNIS), Sapienza University of Rome, 00185 Rome, Italy.
- Department of Astronautics, Electrical and Energy Engineering (DIAEE), Sapienza University of Rome, 00184 Rome, Italy.
| | - Marco Fortunato
- Nanotechnology Research Center Applied to Engineering (CNIS), Sapienza University of Rome, 00185 Rome, Italy.
- Department of Astronautics, Electrical and Energy Engineering (DIAEE), Sapienza University of Rome, 00184 Rome, Italy.
| | - Maria Sabrina Sarto
- Nanotechnology Research Center Applied to Engineering (CNIS), Sapienza University of Rome, 00185 Rome, Italy.
- Department of Astronautics, Electrical and Energy Engineering (DIAEE), Sapienza University of Rome, 00184 Rome, Italy.
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Wu X, Han Y, Zhang X, Lu C. Highly Sensitive, Stretchable, and Wash-Durable Strain Sensor Based on Ultrathin Conductive Layer@Polyurethane Yarn for Tiny Motion Monitoring. ACS APPLIED MATERIALS & INTERFACES 2016; 8:9936-45. [PMID: 27029616 DOI: 10.1021/acsami.6b01174] [Citation(s) in RCA: 92] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Strain sensors play an important role in the next generation of artificially intelligent products. However, it is difficult to achieve a good balance between the desirable performance and the easy-to-produce requirement of strain sensors. In this work, we proposed a simple, cost-efficient, and large-area compliant strategy for fabricating highly sensitive strain sensor by coating a polyurethane (PU) yarn with an ultrathin, elastic, and robust conductive polymer composite (CPC) layer consisting of carbon black and natural rubber. This CPC@PU yarn strain sensor exhibited high sensitivity with a gauge factor of 39 and detection limit of 0.1% strain. The elasticity and robustness of the CPC layer endowed the sensor with good reproducibility over 10,000 cycles and excellent wash- and corrosion-resistance. We confirmed the applicability of our strain sensor in monitoring tiny human motions. The results indicated that tiny normal physiological activities (including pronunciation, pulse, expression, swallowing, coughing, etc.) could be monitored using this CPC@PU sensor in real time. In particular, the pronunciation could be well parsed from the recorded delicate speech patterns, and the emotions of laughing and crying could be detected and distinguished using this sensor. Moreover, this CPC@PU strain-sensitive yarn could be woven into textiles to produce functional electronic fabrics. The high sensitivity and washing durability of this CPC@PU yarn strain sensor, together with its low-cost, simplicity, and environmental friendliness in fabrication, open up new opportunities for cost-efficient fabrication of high performance strain sensing devices.
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Affiliation(s)
- Xiaodong Wu
- State Key Laboratory of Polymer Materials Engineering, Polymer Research Institute of Sichuan University , Chengdu 610065, China
| | - Yangyang Han
- State Key Laboratory of Polymer Materials Engineering, Polymer Research Institute of Sichuan University , Chengdu 610065, China
| | - Xinxing Zhang
- State Key Laboratory of Polymer Materials Engineering, Polymer Research Institute of Sichuan University , Chengdu 610065, China
| | - Canhui Lu
- State Key Laboratory of Polymer Materials Engineering, Polymer Research Institute of Sichuan University , Chengdu 610065, China
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14
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Wei Y, Chen S, Li F, Lin Y, Zhang Y, Liu L. Highly Stable and Sensitive Paper-Based Bending Sensor Using Silver Nanowires/Layered Double Hydroxides Hybrids. ACS APPLIED MATERIALS & INTERFACES 2015; 7:14182-91. [PMID: 26083146 DOI: 10.1021/acsami.5b03824] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Highly sensitive flexible piezoresistive materials using silver nanowires (AgNWs) composites have been widely researched due to their excellent electrical, optical, and mechanical properties. Intrinsically, AgNWs tend to aggregate in polymer matrix because of the intense depletion-induced interactions, which seriously influence the percolation threshold of the composites. In this study, we report a highly stable and sensitive paper-based bending sensor using the AgNWs and layered double hydroxides (LDHs) to construct a hybrid conductive network in waterborne polyurethane that is easy to destruct and reconstruct under bending deformation. The nonconductive 2D LDH nanosheets are embedded into AgNWs network and assist dispersion of AgNWs, which depends on the hydrogen bonding between the two nanostructures. The percolation threshold of the composites decreases from 10.8 vol % (55 wt %) to 3.1 vol % (23.8 wt %), and the composites reaches a very low resistivity (10(-4) Ω·cm) with a small amount of AgNWs (8.3 vol %) due to the dispersion improvement of AgNWs with the effect of LDH nanosheets. The as-prepared conductive composites with low percolation threshold can be manufactured on paper via various methods such as rollerball pen writing, inkjet printing, or screen printing. The bending sensor prepared by manufacturing the composites on paper shows low-cost, excellent conductivity, flexibility (>3000 bending cycles), sensitivity (0.16 rad(-1)), fast response (120 ms) and relaxation time (105 ms), and nontoxicity. Therefore, a simple but efficient wearable sensor is developed to monitor the human motions (such as fingers and elbow joints movements) and presents good repeatability, stability, and responsiveness, making the bending sensor possibly able to meet the needs in numerous applications for robotic systems.
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Affiliation(s)
- Yong Wei
- College of Materials Science and Engineering, Key Lab of Guangdong Province for High Property and Functional Macromolecular Materials, South China University of Technology, Guangzhou 510641, P. R. China
| | - Shilong Chen
- College of Materials Science and Engineering, Key Lab of Guangdong Province for High Property and Functional Macromolecular Materials, South China University of Technology, Guangzhou 510641, P. R. China
| | - Fucheng Li
- College of Materials Science and Engineering, Key Lab of Guangdong Province for High Property and Functional Macromolecular Materials, South China University of Technology, Guangzhou 510641, P. R. China
| | - Yong Lin
- College of Materials Science and Engineering, Key Lab of Guangdong Province for High Property and Functional Macromolecular Materials, South China University of Technology, Guangzhou 510641, P. R. China
| | - Ying Zhang
- College of Materials Science and Engineering, Key Lab of Guangdong Province for High Property and Functional Macromolecular Materials, South China University of Technology, Guangzhou 510641, P. R. China
| | - Lan Liu
- College of Materials Science and Engineering, Key Lab of Guangdong Province for High Property and Functional Macromolecular Materials, South China University of Technology, Guangzhou 510641, P. R. China
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15
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BRODUSCH N, YOURDKHANI M, HUBERT P, GAUVIN R. Efficient cross-section preparation method for high-resolution imaging of hard polymer composites with a scanning electron microscope. J Microsc 2015; 260:117-24. [DOI: 10.1111/jmi.12273] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2015] [Accepted: 05/09/2015] [Indexed: 11/29/2022]
Affiliation(s)
- N. BRODUSCH
- Department of Mining and Materials Engineering; McGill University; Montréal Québec Canada
| | - M. YOURDKHANI
- Department of Mechanical Engineering; McGill University; Montréal Québec Canada
| | - P. HUBERT
- Department of Mechanical Engineering; McGill University; Montréal Québec Canada
| | - R. GAUVIN
- Department of Mining and Materials Engineering; McGill University; Montréal Québec Canada
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Zhao H, Bai J. Highly sensitive piezo-resistive graphite nanoplatelet-carbon nanotube hybrids/polydimethylsilicone composites with improved conductive network construction. ACS APPLIED MATERIALS & INTERFACES 2015; 7:9652-9. [PMID: 25898271 DOI: 10.1021/acsami.5b01413] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
The constructions of internal conductive network are dependent on microstructures of conductive fillers, determining various electrical performances of composites. Here, we present the advanced graphite nanoplatelet-carbon nanotube hybrids/polydimethylsilicone (GCHs/PDMS) composites with high piezo-resistive performance. GCH particles were synthesized by the catalyst chemical vapor deposition approach. The synthesized GCHs can be well dispersed in the matrix through the mechanical blending process. Due to the exfoliated GNP and aligned CNTs coupling structure, the flexible composite shows an ultralow percolation threshold (0.64 vol %) and high piezo-resistive sensitivity (gauge factor ∼ 10(3) and pressure sensitivity ∼ 0.6 kPa(-1)). Slight motions of finger can be detected and distinguished accurately using the composite film as a typical wearable sensor. These results indicate that designing the internal conductive network could be a reasonable strategy to improve the piezo-resistive performance of composites.
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Affiliation(s)
- Hang Zhao
- Laboratoire de Mécanique des Sols, Structures et Matériaux, Ecole Centrale Paris, CNRS UMR8579, PRES UniverSud, Grande Voie des Vignes, 92295 Châtenay-Malabry Cedex, France
| | - Jinbo Bai
- Laboratoire de Mécanique des Sols, Structures et Matériaux, Ecole Centrale Paris, CNRS UMR8579, PRES UniverSud, Grande Voie des Vignes, 92295 Châtenay-Malabry Cedex, France
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17
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Zheng S, Deng J, Yang L, Ren D, Yang W, Liu Z, Yang M. A highly-deformable piezoresistive film composed of a network of carbon blacks and highly oriented lamellae of high-density polyethylene. RSC Adv 2015. [DOI: 10.1039/c5ra00224a] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
The electrical resistance change of highly extensible films consisting of a network of carbon blacks in high-density polyethylene, with different regularity of stacked lamellae, is investigated.
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Affiliation(s)
- Shaodi Zheng
- College of Polymer Science and Engineering
- Sichuan University
- State Key Laboratory of Polymer Materials Engineering
- Chengdu
- China
| | - Jie Deng
- College of Polymer Science and Engineering
- Sichuan University
- State Key Laboratory of Polymer Materials Engineering
- Chengdu
- China
| | - Luqiong Yang
- College of Polymer Science and Engineering
- Sichuan University
- State Key Laboratory of Polymer Materials Engineering
- Chengdu
- China
| | - Danqi Ren
- College of Polymer Science and Engineering
- Sichuan University
- State Key Laboratory of Polymer Materials Engineering
- Chengdu
- China
| | - Wei Yang
- College of Polymer Science and Engineering
- Sichuan University
- State Key Laboratory of Polymer Materials Engineering
- Chengdu
- China
| | - Zhengying Liu
- College of Polymer Science and Engineering
- Sichuan University
- State Key Laboratory of Polymer Materials Engineering
- Chengdu
- China
| | - Mingbo Yang
- College of Polymer Science and Engineering
- Sichuan University
- State Key Laboratory of Polymer Materials Engineering
- Chengdu
- China
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18
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Sun T, Wu Z, Zhuo Q, Liu X, Wang Z, Fan H. Surface functionalized boehmite sheets filled epoxy composites with enhanced mechanical and thermal properties. POLYM ADVAN TECHNOL 2014. [DOI: 10.1002/pat.3410] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Tao Sun
- School of Aeronautics and Astronautics, Faculty of Vehicle Engineering and Mechanics, State Key Laboratory of Structural Analysis for Industrial Equipment; Dalian University of Technology; Dalian 116024 China
| | - Zhanjun Wu
- School of Aeronautics and Astronautics, Faculty of Vehicle Engineering and Mechanics, State Key Laboratory of Structural Analysis for Industrial Equipment; Dalian University of Technology; Dalian 116024 China
- Department of Civil and Environmental Engineering; University of Illinois at Urbana-Champaign; 205 North Mathews Avenue Urbana IL 61801 USA
| | - Qin Zhuo
- School of Aeronautics and Astronautics, Faculty of Vehicle Engineering and Mechanics, State Key Laboratory of Structural Analysis for Industrial Equipment; Dalian University of Technology; Dalian 116024 China
| | - Xin Liu
- School of Aeronautics and Astronautics, Faculty of Vehicle Engineering and Mechanics, State Key Laboratory of Structural Analysis for Industrial Equipment; Dalian University of Technology; Dalian 116024 China
| | - Zhi Wang
- School of Aeronautics and Astronautics, Faculty of Vehicle Engineering and Mechanics, State Key Laboratory of Structural Analysis for Industrial Equipment; Dalian University of Technology; Dalian 116024 China
| | - Hongyu Fan
- School of Physics and Materials Engineering; Dalian Nationalities University; Dalian 116600 China
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Xu R, Lu Y, Jiang C, Chen J, Mao P, Gao G, Zhang L, Wu S. Facile fabrication of three-dimensional graphene foam/poly(dimethylsiloxane) composites and their potential application as strain sensor. ACS APPLIED MATERIALS & INTERFACES 2014; 6:13455-13460. [PMID: 25070179 DOI: 10.1021/am502208g] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
A three-dimensional (3D) graphene foam (GF)/poly(dimethylsiloxane) (PDMS) composite was fabricated by infiltrating PDMS into 3D GF, which was synthesized by chemical vapor deposition (CVD) with nickel foam as template. The electrical properties of the GF/PDMS composite under bending stress were investigated, indicating the resistance of the GF/PDMS composite was increased with the bending curvature. To improve the bending sensitivity of the GF/PDMS composite, a thin layer of poly(ethylene terephthalate) (PET) was introduced as substrate to form double-layer GF/PDMS-PET composite, whose measurements showed that the resistance of the GF/PDMS-PET composite was still increased when bended to the side of PET, whereas its resistance would be decreased when bended to the side of GF. For both cases, the absolute value of the relative variation of electrical resistance was increased with the bending curvature. More importantly, the relative variation of electrical resistance for double-layer GF/PDMS-PET composite can be up to six times higher than single-layer GF/PDMS composite for the same bending curvature. These observations were further supported by the principle of mechanics of material. The 3D GF/PDMS-PET composite also has higher flexibility and environment stability and can be utilized as a strain sensor with high sensitivity, which can find important applications in real-time monitoring of buildings, such as a bridge, dam, and high-speed railway.
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Affiliation(s)
- Rongqing Xu
- College of Electronic Science and Engineering and ‡School of Optoelectronic Engineering, Nanjing University of Posts and Telecommunications , Nanjing 210046, China
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