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Negative Temperature Coefficient of Resistance in Aligned CNT Networks: Influence of the Underlying Phenomena. Polymers (Basel) 2023; 15:polym15030678. [PMID: 36771980 PMCID: PMC9921551 DOI: 10.3390/polym15030678] [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: 11/30/2022] [Revised: 01/18/2023] [Accepted: 01/19/2023] [Indexed: 02/03/2023] Open
Abstract
Temperature dependence of electrical conductivity/resistivity of CNT networks (dry or impregnated), which is characterised by a temperature coefficient of resistance (TCR), is experimentally observed to be negative, especially for the case of aligned CNT (A-CNT). The paper investigates the role of three phenomena defining the TCR, temperature dependence of the intrinsic conductivity of CNTs, of the tunnelling resistance of their contacts, and thermal expansion of the network, in the temperature range 300-400 K. A-CNT films, created by rolling down A-CNT forests of different length and described in Lee et al., Appl Phys Lett, 2015, 106: 053110, are investigated as an example. The modelling of the electrical conductivity is performed by the nodal analysis of resistance networks, coupled with the finite-element thermomechanical modelling of network thermal expansion. The calculated TCR for the film is about -0.002 1/K and is close to the experimentally observed values. Comparative analysis of the influence of the TCR defining phenomena is performed on the case of dry and impregnated films. The analysis shows that in both cases, for an A-CNT film at the studied temperature interval, the main factor affecting a network's TCR is the TCR of the CNTs themselves. The TCR of the tunnelling contacts plays the secondary role; influence of the film thermal expansion is marginal. The prevailing impact of the intrinsic conductivity TCR on the TCR of the film is explained by long inter-contact segments of CNTs in an A-CNT network, which define the homogenised film conductivity.
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2
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Jafarypouria M, Mahato B, Abaimov SG. Separating Curing and Temperature Effects on the Temperature Coefficient of Resistance for a Single-Walled Carbon Nanotube Nanocomposite. Polymers (Basel) 2023; 15:polym15020433. [PMID: 36679312 PMCID: PMC9865132 DOI: 10.3390/polym15020433] [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: 12/05/2022] [Revised: 12/29/2022] [Accepted: 01/09/2023] [Indexed: 01/15/2023] Open
Abstract
The temperature coefficient of resistance (TCR) determines the electrical performance of materials in electronics. For a carbon nanotube (CNT) nanocomposite, change of resistivity with temperature depends on changes in CNT intrinsic conductivity, tunnelling thresholds and distances, matrix' coefficient of thermal expansion, and other factors. In our study, we add one more influencing factor-the degree of cure. Complexities of the curing process cause difficulties to predict, or even measure, the curing state of the polymer matrix while uncertainty in the degree of cure influences TCR measurements leading to biased values. Here we study the influence of the cure state on the TCR of a single-walled CNT/epoxy polymer nanocomposite. For the given degree of cure, TCR measurements are conducted in the temperature range 25-100 °C, followed by the next 24 h of post-curing and a new cycle of measurements, 8 cycles in total. We find that contrary to industry practice to expect a high degree of cure after 3 h at 130 °C, the curing process is far from reaching the steady state of the material and continues at least for the next 72 h at 120 °C, as we observe by changes in the material electrical resistivity. If TCR measurements are conducted in this period, we find them significantly influenced by the post-curing process continuing in parallel, leading in particular to non-monotonic temperature dependence and the appearance of negative values. The unbiased TCR values we observe only when the material reaches the steady state are no longer influenced by the heat input. The dependence becomes steady, monotonically increasing from near zero value at room temperature to 0.001 1/°C at 100 °C.
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Elseady AAE, Lee I, Zhuge Y, Ma X, Chow CWK, Gorjian N. Piezoresistivity and AC Impedance Spectroscopy of Cement-Based Sensors: Basic Concepts, Interpretation, and Perspective. MATERIALS (BASEL, SWITZERLAND) 2023; 16:768. [PMID: 36676505 PMCID: PMC9865006 DOI: 10.3390/ma16020768] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/05/2022] [Revised: 01/09/2023] [Accepted: 01/10/2023] [Indexed: 06/17/2023]
Abstract
Cement-based sensors include conductive fillers to achieve a sensing capability based on the piezoresistivity phenomenon, in which the electrical resistivity changes with strain. The microstructural characterisation of cement-based sensors can be obtained using a promising non-destructive technique, such as AC impedance spectroscopy (ACIS), which has been recently used by many researchers. This paper reviews the fundamental concepts of piezoresistivity and ACIS in addition to the comparison of equivalent circuit models of cement-based sensors found in the literature. These concepts include piezoresistivity theory, factors affecting piezoresistivity measurement, resistance measurement methodology, strain/damage sensing, causes of piezoresistivity, theories of conduction, AC impedance spectroscopy theory, and the equivalent circuit model. This review aims to provide a comprehensive guide for researchers and practitioners interested in exploring and applying different techniques to self-sensing concrete.
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Affiliation(s)
- Amir A. E. Elseady
- Sustainable Infrastructure and Resource Management (SIRM), UniSA STEM, University of South Australia, Adelaide, SA 5095, Australia
| | - Ivan Lee
- Sustainable Infrastructure and Resource Management (SIRM), UniSA STEM, University of South Australia, Adelaide, SA 5095, Australia
| | - Yan Zhuge
- Sustainable Infrastructure and Resource Management (SIRM), UniSA STEM, University of South Australia, Adelaide, SA 5095, Australia
| | - Xing Ma
- Sustainable Infrastructure and Resource Management (SIRM), UniSA STEM, University of South Australia, Adelaide, SA 5095, Australia
| | - Christopher W. K. Chow
- Sustainable Infrastructure and Resource Management (SIRM), UniSA STEM, University of South Australia, Adelaide, SA 5095, Australia
| | - Nima Gorjian
- South Australian Water Corporation, Adelaide, SA 5095, Australia
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High-Temperature Response Polylactic Acid Composites by Tuning Double-Percolated Structures. Polymers (Basel) 2022; 15:polym15010138. [PMID: 36616486 PMCID: PMC9824055 DOI: 10.3390/polym15010138] [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: 12/02/2022] [Revised: 12/21/2022] [Accepted: 12/24/2022] [Indexed: 12/30/2022] Open
Abstract
Due to the properties of a positive temperature coefficient (PTC) effect and a negative temperature coefficient (NTC) effect, electrically conductive polymer composites (CPCs) have been widely used in polymer thermistors. A dual percolated conductive microstructure was prepared by introducing the polybutylene adipate terephthalate phase (PBAT) into graphene nanoplatelets (GNPs)-filled polylactic acid (PLA) composites, intending to develop a favorable and stable PTC material. To achieve this strategy, GNPs were selectively distributed in the PBAT phase by injection molding. In this study, we investigated the crystallization behavior, electrical conductivity, and temperature response of GNP-filled PLA/PBAT composites. The introduction of GNPs into PLA significantly increased PLA crystallization capacity, where the crystallization onset temperature (To) is raised from 116.7 °C to 134.7 °C, and the crystallization half-time (t1/2) decreases from 35.8 min to 27.3 min. The addition of 5 wt% PBAT increases the electrical conductivity of PLA/PBAT/GNPs composites by almost two orders of magnitude when compared to PLA/GNPs counterparts. The temperature of the heat treatment is also found to play a role in affecting the electrical conductivity of PLA-based composites. Increasing crystallinity is favorable for increasing electrical conductivity. PLA/PBAT/GNPs composites also show a significant positive temperature coefficient, which is reflected in the temperature-electrical resistance cycling tests.
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5
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Asymmetrically functionalized CNTs: preparation of polymer nanocomposites and investigation of interfacial properties. JOURNAL OF POLYMER RESEARCH 2022. [DOI: 10.1007/s10965-022-03269-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
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6
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Shin G, Lee S, Park YL. Selective Patterning of Conductive Elastomers Embedded With Silver Powders and Carbon Nanotubes for Stretchable Electronics. IEEE Robot Autom Lett 2022. [DOI: 10.1109/lra.2022.3153707] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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7
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Inferring the energy sensitivity and band gap of electronic transport in a network of carbon nanotubes. Sci Rep 2022; 12:2060. [PMID: 35136140 PMCID: PMC8826413 DOI: 10.1038/s41598-022-06078-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2021] [Accepted: 01/11/2022] [Indexed: 12/05/2022] Open
Abstract
Since the industrialization of single-phase nanomaterial-based devices is still challenging, intensive research focus has been given to complex materials consisting of multiple nanoscale entities, including networks and matrices of nanowires, nanotubes, nanoribbons, or other large molecules; among these complex materials, networks of carbon nanotubes are a typical example. Detailed knowledge of the energy sensitivity and band gap of electronic transport in such a material system is difficult to detect, despite its importance in electronic, energetic and sensing applications. Here, we propose a new methodology to obtain these quantities using the measured Seebeck coefficient at a certain temperature but different Fermi levels. We discover that the network consisting of semiconducting (11,10)-carbon nanotubes actually exhibits metallic transport at room temperature. It is also interesting to verify that intrananotube ballistic transport is dominant over diffusive scattering by long-range disorder, as well as the quantum hopping resistance at the contact points. The transport asymmetry ratio between the holes and electrons (1.75) is similar to the value observed in pristine graphene samples (1.50).
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Yulianti R, Irmawati Y, Destyorini F, Ghozali M, Suhandi A, Kartolo S, Hardiansyah A, Byun JH, Fauzi MH, Yudianti R. Highly Stretchable and Sensitive Single-Walled Carbon Nanotube-Based Sensor Decorated on a Polyether Ester Urethane Substrate by a Low Hydrothermal Process. ACS OMEGA 2021; 6:34866-34875. [PMID: 34963970 PMCID: PMC8697591 DOI: 10.1021/acsomega.1c05543] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/05/2021] [Accepted: 11/23/2021] [Indexed: 06/14/2023]
Abstract
We report a highly stretchable sensor with low-concentration (1.5 wt %) single-walled carbon nanotubes (SWCNTs) on flexible polyether ester urethane (PEEU) yarn, fabricated using a low hydrothermal process at 90 °C. Although SWCNTs restrict the PEEU polymer chain mobility, the resulting ductility of our nanocomposites reduces only by 16.5% on average, initially from 667.3% elongation at break to 557.2%. The resulting electrical resistivity of our nanocomposites can be controlled systematically by the number of hydrothermal cycles. A high gauge factor value of 4.84 is achieved at a tensile strain below 100%, and it increases up to 28.5 with applying a tensile strain above 450%. We find that the piezoresistivity of our nanocomposite is sensitive to temperature variations of 25-85 °C due to the hopping effect, which promotes more charge transport at elevated temperatures. Our nanocomposites offer both a high sensitivity and a large strain sensing range, which is achieved with a relatively simple fabrication technique and low concentration of SWCNTs.
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Affiliation(s)
- Riyani
Tri Yulianti
- Research
Center for Physics, Indonesian Institute of Sciences, Kawasan Puspiptek, South Tangerang 15314, Indonesia
| | - Yuyun Irmawati
- Research
Center for Physics, Indonesian Institute of Sciences, Kawasan Puspiptek, South Tangerang 15314, Indonesia
| | - Fredina Destyorini
- Research
Center for Physics, Indonesian Institute of Sciences, Kawasan Puspiptek, South Tangerang 15314, Indonesia
| | - Muhammad Ghozali
- Research
Center for Chemistry, Indonesian Institute of Sciences, Kawasan Puspiptek, South Tangerang 15314, Indonesia
| | - Andi Suhandi
- Research
Center for Physics, Indonesian Institute of Sciences, Kawasan Puspiptek, South Tangerang 15314, Indonesia
| | - Surip Kartolo
- Research
Center for Physics, Indonesian Institute of Sciences, Kawasan Puspiptek, South Tangerang 15314, Indonesia
| | - Andri Hardiansyah
- Research
Center for Physics, Indonesian Institute of Sciences, Kawasan Puspiptek, South Tangerang 15314, Indonesia
| | - Joon-Hyun Byun
- Korea
Institute of Materials Science, 797 Changwondaero, Changwon 642-831, South Korea
| | - Mohammad Hamzah Fauzi
- Research
Center for Physics, Indonesian Institute of Sciences, Kawasan Puspiptek, South Tangerang 15314, Indonesia
| | - Rike Yudianti
- Research
Center for Physics, Indonesian Institute of Sciences, Kawasan Puspiptek, South Tangerang 15314, Indonesia
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9
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Qi XD, Yang JH, Zhang N, Huang T, Zhou ZW, Kühnert I, Pötschke P, Wang Y. Selective localization of carbon nanotubes and its effect on the structure and properties of polymer blends. Prog Polym Sci 2021. [DOI: 10.1016/j.progpolymsci.2021.101471] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
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10
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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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11
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Multilayered Composites with Modulus Gradient for Enhanced Pressure-Temperature Sensing Performance. SENSORS 2021; 21:s21144752. [PMID: 34300493 PMCID: PMC8309777 DOI: 10.3390/s21144752] [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: 06/07/2021] [Revised: 07/01/2021] [Accepted: 07/05/2021] [Indexed: 11/16/2022]
Abstract
Highly sensitive and flexible composite sensors with pressure and temperature sensing abilities are of great importance in human motion monitoring, robotic skins, and automobile seats when checking the boarding status. Several studies have been conducted to improve the temperature-pressure sensitivity; however, they require a complex fabrication process for micro-nanostructures, which are material-dependent. Therefore, there is a need to develop the structural designs to improve the sensing abilities. Herein, we demonstrate a flexible composite with an enhanced pressure and temperature sensing performance. Its structural design consists of a multilayered composite construction with an elastic modulus gradient. Controlled stress concentration and distribution induced by a micropatterned structure between the layers improves its pressure and temperature sensing performance. The proposed composite sensor can monitor a wide range of pressure and temperature stimuli and also has potential applications as an automotive seat sensor for simultaneous human temperature detection and occupant weight sensing.
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12
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Gogurla N, Kim Y, Cho S, Kim J, Kim S. Multifunctional and Ultrathin Electronic Tattoo for On-Skin Diagnostic and Therapeutic Applications. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2021; 33:e2008308. [PMID: 33955069 DOI: 10.1002/adma.202008308] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/09/2020] [Revised: 03/10/2021] [Indexed: 05/02/2023]
Abstract
Epidermal electronic systems for detecting electrophysiological signals, sensing, therapy, and drug delivery are at the frontier in man-machine interfacing for healthcare. However, it is still a challenge to develop multifunctional bioapplications with minimal invasiveness, biocompatibility, and stable electrical performance under various mechanical deformations of biological tissues. In this study, a natural silk protein with carbon nanotubes (CNTs) is utilized to realize an epidermal electronic tattoo (E-tattoo) system for multifunctional applications that address these challenging issues through dispersing highly conductive CNTs onto the biocompatible silk nanofibrous networks with porous nature to construct skin-adhesive ultrathin electronic patches. Individual components that incorporate electrically and optically active heaters, a temperature sensor (temperature coefficient of resistance of 5.2 × 10-3 °C-1 ), a stimulator for drug delivery (>500 µm penetration depth in skin), and real-time electrophysiological signal detectors are described. This strategy of E-tattoos integrated onto human skin can open a new route to a next-generation electronic platform for wearable and epidermal bioapplications.
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Affiliation(s)
- Narendar Gogurla
- Basic Science Research Center, Department of Physics, and Department of Energy Systems Research, Ajou University, Suwon, 16499, Republic of Korea
| | - Yisub Kim
- Panoptics Corporation, Seongnam, 13516, Republic of Korea
| | - Suyoung Cho
- Panoptics Corporation, Seongnam, 13516, Republic of Korea
| | - Jangsun Kim
- Panoptics Corporation, Seongnam, 13516, Republic of Korea
| | - Sunghwan Kim
- Basic Science Research Center, Department of Physics, and Department of Energy Systems Research, Ajou University, Suwon, 16499, Republic of Korea
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13
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Meng Q, Araby S, Oh J, Chand A, Zhang X, Kenelak V, Ma J, Liu T, Ma J. Accurate self‐damage detection by electrically conductive epoxy/graphene nanocomposite film. J Appl Polym Sci 2021. [DOI: 10.1002/app.50452] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Affiliation(s)
- Qingshi Meng
- College of Aerospace Engineering Shenyang Aerospace University Shenyang China
| | - Sherif Araby
- School of Engineering and Digital Sciences Nazarbayev University Nur‐Sultan Kazakhstan
- Department of Mechanical Engineering, Benha Faculty of Engineering Benha University Benha Egypt
| | - Jeong‐A Oh
- University of South Australia UniSA STEM and Future Industries Institute Mawson Lakes South Australia Australia
| | - Aron Chand
- College of Aerospace Engineering Shenyang Aerospace University Shenyang China
| | - Xuming Zhang
- College of Aerospace Engineering Shenyang Aerospace University Shenyang China
| | - Vincent Kenelak
- College of Aerospace Engineering Shenyang Aerospace University Shenyang China
| | - Jian Ma
- Administrative Department Shenyang Aerospace University Shenyang China
| | - Tianqing Liu
- NICM Health Research Institute Western Sydney University Sydney New South Wales Australia
| | - Jun Ma
- University of South Australia UniSA STEM and Future Industries Institute Mawson Lakes South Australia Australia
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14
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Abdulhameed A, Halin IA, Mohtar MN, Hamidon MN. Airflow-assisted dielectrophoresis to reduce the resistance mismatch in carbon nanotube-based temperature sensors. RSC Adv 2021; 11:39311-39318. [PMID: 35492445 PMCID: PMC9044456 DOI: 10.1039/d1ra08250g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2021] [Accepted: 11/30/2021] [Indexed: 11/21/2022] Open
Abstract
Airflow-assisted dielectrophoresis (AA-DEP) is a novel dielectrophoresis (DEP) setup used to fabricate sensor devices with minimum resistance variation by assembling and aligning carbon nanotubes (CNTs) across electrode structures.
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Affiliation(s)
- Abdullah Abdulhameed
- Department of Electronic Engineering, Faculty of Engineering, Hadhramout University, Mukalla, Yemen
- Department of Electrical and Electronic Engineering, Faculty of Engineering, Universiti Putra Malaysia, Serdang, 43400, Malaysia
| | - Izhal Abdul Halin
- Department of Electrical and Electronic Engineering, Faculty of Engineering, Universiti Putra Malaysia, Serdang, 43400, Malaysia
| | - Mohd Nazim Mohtar
- Department of Electrical and Electronic Engineering, Faculty of Engineering, Universiti Putra Malaysia, Serdang, 43400, Malaysia
- Institute of Advanced Technology (ITMA), Universiti Putra Malaysia, Serdang, 43400, Malaysia
| | - Mohd Nizar Hamidon
- Department of Electrical and Electronic Engineering, Faculty of Engineering, Universiti Putra Malaysia, Serdang, 43400, Malaysia
- Institute of Advanced Technology (ITMA), Universiti Putra Malaysia, Serdang, 43400, Malaysia
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15
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Guo J, Zhang K, Dai R, Nie M, Li Y, Wang Q. Flexible Sensor for Invisible Respiratory Monitoring via Construction of a 2D Stacked Micronetwork. ACS OMEGA 2020; 5:32806-32813. [PMID: 33376919 PMCID: PMC7758983 DOI: 10.1021/acsomega.0c05367] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/03/2020] [Accepted: 12/02/2020] [Indexed: 06/12/2023]
Abstract
With the advent of 5G and the Internet of Things era, sensitive and stable sensors have begun to develop rapidly, which are important substantial fundaments of smart medical care. In this study, based on the positive temperature coefficient (PTC) in conductive polymer composites (CPC), a novel polyolefin elastomer (POE)/carbon fiber (CF) composite was prepared. By regulating the rheological behavior of the polymer matrix, we realized its controllable thermal expansion in the temperature field and finally realized the reversible construction-destruction of the conductive CF network. Under optimal molecular weight conditions, the POE/CF PTC sensor showed a high sensitivity of 0.11 °C-1 and stability. It was also demonstrated that the heat transfer efficiency of the composite material played an essential role in the sensitivity of the as-prepared PTC sensor. Most impressively, we have assembled an invisible respiratory monitoring device based on the POE/CF composite to achieve real-time monitoring of human breathing, which displayed wide potential prospects in thermal monitoring and provided good prospects for micron-scale functional composites.
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Sethy S, Samantara L, Satapathy BK. Phase‐selective micro‐structural effects on rheological‐networks, segmental relaxation, and electrical conductivity behavior of melt‐mixed polyamide‐12/polypropylene‐multi walled carbon nanotubes ternary nanocomposites. POLYM ENG SCI 2020. [DOI: 10.1002/pen.25381] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Sucharita Sethy
- Department of Materials Science and EngineeringIndian Institute of Technology Delhi Hauz Khas New Delhi India
| | | | - Bhabani K. Satapathy
- Department of Materials Science and EngineeringIndian Institute of Technology Delhi Hauz Khas New Delhi India
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17
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Jeong Y, Park J, Lee J, Kim K, Park I. Ultrathin, Biocompatible, and Flexible Pressure Sensor with a Wide Pressure Range and Its Biomedical Application. ACS Sens 2020; 5:481-489. [PMID: 32020796 DOI: 10.1021/acssensors.9b02260] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
In this research, an ultrathin, biocompatible, and flexible pressure sensor with a wide pressure range has been developed and applied in biomedical applications. The pressure sensing mechanism is based on the variation of contact resistance between an electrode and a three-dimensional microstructured polyimide/carbon nanotube composite film. The sensor has a thickness of about 31.3 μm, a maximum sensitivity of 41.0 MPa-1, and a sensing range of 10-500 kPa. Moreover, in situ temperature measurement by an integrated resistive temperature detector enables data correction for varying temperature conditions. In order to show the advantages of the fabricated sensor, it is attached to the human body and integrated with the surface of a radiofrequency ablation (RFA) needle with small radius of curvature. In the experiments, the proposed pressure sensor measured subtle pressure levels (pulse pressure) and high pressure levels (fingertip pressure) without losing conformal contact with the skin. In addition, when the pressure-sensor-integrated RFA needle was inserted into a bovine liver, successful detection of steam popping phenomenon was observed.
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Affiliation(s)
- Yongrok Jeong
- Department of Mechanical Engineering, Korea Advanced Institute of Science and Technology, 291, Daehak-ro, Yuseong-gu, Daejeon 34141, Republic of Korea
| | - Jaeho Park
- Department of Mechanical Engineering, Korea Advanced Institute of Science and Technology, 291, Daehak-ro, Yuseong-gu, Daejeon 34141, Republic of Korea
| | - Jinwoo Lee
- RF Medical. Co. Ltd., 254, Beotkkot-ro, Geumcheon-gu, Seoul 08511, Republic of Korea
| | - Kyuyoung Kim
- Department of Mechanical Engineering, Korea Advanced Institute of Science and Technology, 291, Daehak-ro, Yuseong-gu, Daejeon 34141, Republic of Korea
| | - Inkyu Park
- Department of Mechanical Engineering, Korea Advanced Institute of Science and Technology, 291, Daehak-ro, Yuseong-gu, Daejeon 34141, Republic of Korea
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18
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Jang Y, Kim SM, Spinks GM, Kim SJ. Carbon Nanotube Yarn for Fiber-Shaped Electrical Sensors, Actuators, and Energy Storage for Smart Systems. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2020; 32:e1902670. [PMID: 31403227 DOI: 10.1002/adma.201902670] [Citation(s) in RCA: 69] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/26/2019] [Revised: 06/18/2019] [Indexed: 06/10/2023]
Abstract
Smart systems are those that display autonomous or collaborative functionalities, and include the ability to sense multiple inputs, to respond with appropriate operations, and to control a given situation. In certain circumstances, it is also of great interest to retain flexible, stretchable, portable, wearable, and/or implantable attributes in smart electronic systems. Among the promising candidate smart materials, carbon nanotubes (CNTs) exhibit excellent electrical and mechanical properties, and structurally fabricated CNT-based fibers and yarns with coil and twist further introduce flexible and stretchable properties. A number of notable studies have demonstrated various functions of CNT yarns, including sensors, actuators, and energy storage. In particular, CNT yarns can operate as flexible electronic sensors and electrodes to monitor strain, temperature, ionic concentration, and the concentration of target biomolecules. Moreover, a twisted CNT yarn enables strong torsional actuation, and coiled CNT yarns generate large tensile strokes as an artificial muscle. Furthermore, the reversible actuation of CNT yarns can be used as an energy harvester and, when combined with a CNT supercapacitor, has promoted the next-generation of energy storage systems. Here, progressive advances of CNT yarns in electrical sensing, actuation, and energy storage are reported, and the future challenges in smart electronic systems considered.
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Affiliation(s)
- Yongwoo Jang
- Center for Self-Powered Actuation, Department of Biomedical Engineering, Hanyang University, Seoul, 04763, South Korea
| | - Sung Min Kim
- Department of Physical Education, Department of Active Aging Industry, Hanyang University, Seoul, 04763, South Korea
| | - Geoffrey M Spinks
- Australian Institute for Innovative Materials, ARC Centre of Excellence for Electromaterials Science, University of Wollongong, Wollongong, NSW, 2522, Australia
| | - Seon Jeong Kim
- Center for Self-Powered Actuation, Department of Biomedical Engineering, Hanyang University, Seoul, 04763, South Korea
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Ramli MR, Ibrahim S, Ahmad Z, Abidin ISZ, Ain MF. Stretchable Conductive Ink Based on Polysiloxane-Silver Composite and Its Application as a Frequency Reconfigurable Patch Antenna for Wearable Electronics. ACS APPLIED MATERIALS & INTERFACES 2019; 11:28033-28042. [PMID: 31314485 DOI: 10.1021/acsami.9b07671] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
The rapid progress in electronic applications for movable devices requires the conductive matrix to be not only flexible but also stretchable. A simple microstrip patch antenna was fabricated based on silver ink polysiloxane composite with a stretchable polysiloxane substrate at a resonance frequency of 2.50 GHz. It is designed at a postpercolation threshold of 35, 45, and 60 vol % conductive filler loading so as to allow a consistent conductivity at an ample range of cyclic stretching. With the presence of coupling agent and additives, the patch antenna displayed an extremely good adhesion between the ink and the substrate, which prevents any local rupture during stretching. Variable range hopping model verified that conductivity occurs through hopping and tunneling mechanisms, giving transient optimum conductivity in the range of 10-70 S/cm at 10-20% strain amplitude range. The fabricated prototype of microstrip patch antenna displayed a decreasing resonant frequency with strain. Of note, the radiation loss S11 and the bandwidth values are proportionally related to the conductivities during stretching. These results verified the proposed mechanisms of construction and destruction of conductivity occurring during the percolation threshold process. The fabricated antenna proved the feasibility for use as a stretchable device at an ultrahigh-frequency band.
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20
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Smirnov S, Anoshkin IV, Generalov A, Lioubtchenko DV, Oberhammer J. Wavelength-dependent photoconductivity of single-walled carbon nanotube layers. RSC Adv 2019; 9:14677-14682. [PMID: 35516325 PMCID: PMC9064124 DOI: 10.1039/c9ra01467e] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2019] [Accepted: 04/30/2019] [Indexed: 11/23/2022] Open
Abstract
A number of electronic devices such as phase shifters, polarizers, modulators, and power splitters are based on tunable materials. These materials often do not meet all the requirements namely low losses, fast response time, and technological compatibility. Novel nanomaterials, such as single-walled carbon nanotubes, are therefore widely studied to fill this technological gap. Here we show how the dielectric constant of single-walled carbon nanotube layers can be substantially modified by illuminating them due to unique light–matter interactions. We relate the optical excitation of the nanotube layers to the illumination wavelength and intensity, by resistance and capacitance measurements. The dielectric constant is modified under laser illumination due to the change of material polarization and free carrier generation, and is shown to not be temperature-related. The findings indicate that SWCNT layers are a prospective tunable optoelectronic material for both high and low frequency applications. The optically-tunable dielectric properties of single-walled carbon nanotube layers are wavelength-dependent.![]()
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Affiliation(s)
- Serguei Smirnov
- Department of Micro and Nanosystems
- KTH Royal Institute of Technology
- SE-100 44 Stockholm
- Sweden
| | - Ilya V. Anoshkin
- Department of Photonics and Optical Information Technologies
- ITMO University
- 197101 Saint Petersburg
- Russian Federation
| | - Andrey Generalov
- Department of Electronics and Nanoengineering
- Aalto University
- Finland
| | - Dmitri V. Lioubtchenko
- Department of Micro and Nanosystems
- KTH Royal Institute of Technology
- SE-100 44 Stockholm
- Sweden
- Center for Terahertz Research and Applications (CENTERA)
| | - Joachim Oberhammer
- Department of Micro and Nanosystems
- KTH Royal Institute of Technology
- SE-100 44 Stockholm
- Sweden
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Simulation of contact phenomena in systems based on oligoethers and carbon nanotubes. Polym J 2018. [DOI: 10.15407/polymerj.40.02.113] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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Hoang LT, Leung SN, Zhu ZH. Eliminating common biases in modelling the electrical conductivity of carbon nanotube-polymer nanocomposites. Phys Chem Chem Phys 2018; 20:13118-13121. [PMID: 29721559 DOI: 10.1039/c8cp01715h] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Modelling carbon nanotube-polymer nanocomposites to predict their electrical conductivity demands high computational power. Past research has led to the assumption that conductive networks follow a periodic pattern; however, the impact of the underlying biases had never been investigated. This work provides insights into evaluating such biases and eliminating them to improve simulation accuracy.
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Affiliation(s)
- Linh Trong Hoang
- Department of Physics & Astronomy, York University, Toronto, ON M3J 1P3, Canada
| | - Siu Ning Leung
- Department of Mechanical Engineering, York University, Toronto, ON M3J 1P3, Canada.
| | - Zheng Hong Zhu
- Department of Mechanical Engineering, York University, Toronto, ON M3J 1P3, Canada.
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Transparent Low Electrostatic Charge Films Based on Carbon Nanotubes and Polypropylene. Homopolymer Cast Films. Polymers (Basel) 2018; 10:polym10010055. [PMID: 30966091 PMCID: PMC6415039 DOI: 10.3390/polym10010055] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2017] [Revised: 12/20/2017] [Accepted: 01/03/2018] [Indexed: 11/16/2022] Open
Abstract
Use of multi-wall carbon nanotubes (MWCNTs) in external layers (A-layers) of ABA-trilayer polypropylene films was investigated, with the purpose of determining intrinsic and extrinsic factors that could lead to antistatic behavior of transparent films. The incorporation of 0.01, 0.1, and 1 wt % of MWCTNs in the A-layers was done by dilution through the masterbatch method. Masterbatches were fabricated using isotactic polypropylene (iPP) with different melt flow indexes 2.5, 34, and 1200 g/10 min, and using different ultrasound assist methods. It was found that films containing MWCNTs show surface electrical resistivity of 1012 and 1016 Ω/sq, regardless of the iPP melt flow index (MFI) and masterbatch fabrication method. However, electrostatic charge was found to depend upon the iPP MFI, the ultrasound assist method and MWCNT concentration. A percolation electron transport mechanism was determined most likely responsible for this behavior. Optical properties for films containing MWCNTs do not show significant differences compared to the reference film at MWCNT concentrations below 0.1 wt %. However, an enhancement in brightness was observed, and it was attributed to ordered iPP molecules wrapping the MWCNTs. Bright transparent films with low electrostatic charge were obtained even for MWCNTs concentrations as low as 0.01 wt %.
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