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Kang BC, Park SJ, Ha TJ. Wearable Pressure/Touch Sensors Based on Hybrid Dielectric Composites of Zinc Oxide Nanowires/Poly(dimethylsiloxane) and Flexible Electrodes of Immobilized Carbon Nanotube Random Networks. ACS APPLIED MATERIALS & INTERFACES 2021; 13:42014-42023. [PMID: 34450010 DOI: 10.1021/acsami.1c10961] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Capacitive-type physical sensors based on hybrid dielectric composites of zinc oxide nanowires/poly(dimethylsiloxane) (ZnO NWs@PDMS) and flexible electrodes of immobilized carbon nanotube (CNT) random networks, which are highly sensitive to pressure and touch stimuli, are demonstrated. Immobilized CNT random networks densely entangled in a Nafion matrix improve the electrical stability of wearable pressure sensors against mechanical stress with a bending radius of 5 mm. The effect of ZnO NW incorporation into PDMS on the sensing performance of pressure sensors is investigated, which results in a significantly enhanced sensitivity of 8.77 × 10-4 Pa-1 in low-pressure regions, compared to pristine PDMS (1.32 × 10-4 Pa-1). This improvement is attributed to the increase in the effective dielectric constant (εr) of the hybrid dielectric composites with their piezoelectric properties. In addition, wearable pressure/touch sensor arrays capable of detecting ultralow pressures (down to 20 Pa) and the real-time identification of touch and pressure stimuli via different sensing mechanisms are demonstrated. We believe that the multifunctionality introduced by the proposed sensors can extend the potential of physical sensor applications, while they are suitable for integration with wearable electronics based on hybrid nanocomposites and interfaces.
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Affiliation(s)
- Byeong-Cheol Kang
- Department of Electronic Materials Engineering, Kwangwoon University, Seoul 01897, Republic of Korea
| | - Sang-Joon Park
- Department of Electronic Materials Engineering, Kwangwoon University, Seoul 01897, Republic of Korea
| | - Tae-Jun Ha
- Department of Electronic Materials Engineering, Kwangwoon University, Seoul 01897, Republic of Korea
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Guan F, Xie Y, Wu H, Meng Y, Shi Y, Gao M, Zhang Z, Chen S, Chen Y, Wang H, Pei Q. Silver Nanowire-Bacterial Cellulose Composite Fiber-Based Sensor for Highly Sensitive Detection of Pressure and Proximity. ACS NANO 2020; 14:15428-15439. [PMID: 33030887 DOI: 10.1021/acsnano.0c06063] [Citation(s) in RCA: 57] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Fiber-based sensors are desirable to provide an immersive experience for users in the human-computer interface. We report a hierarchically porous silver nanowire-bacterial cellulose fiber that can be utilized for sensitive detection of both pressure and proximity of human fingers. The conductive fiber was synthesized via continuous wet-spinning at a speed of 20 m/min, with a diameter of 53 μm, the electrical conductivity of 1.3 × 104 S/cm, a tensile strength of 198 MPa, and elongation strain of 3.0% at break. The fibers were coaxially coated with a 10 μm thick poly(dimethylsiloxane) dielectric elastomer to form the fiber sensor element which is thinner than a human hair. Two of the sensor fibers were laid diagonally, and the capacitance changes between the conductive cores were measured in response to pressure and proximity. In the touch mode, a fiber-based sensor experienced monotonic capacitance increase in the pressure range from 0 to 460 kPa, and a linear response with a high sensitivity of 5.49 kPa-1 was obtained in the low-pressure regime (<0.5 kPa). In touchless mode, the sensor is highly sensitive to objects at a distance of up to 30 cm. Also, the fiber can be easily stitched into garments as comfortable and fashionable sensors to detect heartbeat and vocal pulses. A fiber sensor array is able to serve as a touchless piano to play music and accurately determine the proximity of an object. A 2 × 2 array was further shown for two- and three-dimensional location detection of remote objects.
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Affiliation(s)
- Fangyi Guan
- Department of Materials Science and Engineering, Henry Samueli School of Engineering and Applied Science, University of California, Los Angeles, California 90095, United States
- State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, College of Materials Science and Engineering, Donghua University, Shanghai 201620, P.R. China
| | - Yu Xie
- Department of Materials Science and Engineering, Henry Samueli School of Engineering and Applied Science, University of California, Los Angeles, California 90095, United States
| | - Hanxiang Wu
- Department of Materials Science and Engineering, Henry Samueli School of Engineering and Applied Science, University of California, Los Angeles, California 90095, United States
| | - Yuan Meng
- Department of Materials Science and Engineering, Henry Samueli School of Engineering and Applied Science, University of California, Los Angeles, California 90095, United States
| | - Ye Shi
- Department of Materials Science and Engineering, Henry Samueli School of Engineering and Applied Science, University of California, Los Angeles, California 90095, United States
| | - Meng Gao
- Department of Materials Science and Engineering, Henry Samueli School of Engineering and Applied Science, University of California, Los Angeles, California 90095, United States
| | - Ziyang Zhang
- Department of Materials Science and Engineering, Henry Samueli School of Engineering and Applied Science, University of California, Los Angeles, California 90095, United States
| | - Shiyan Chen
- State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, College of Materials Science and Engineering, Donghua University, Shanghai 201620, P.R. China
| | - Ye Chen
- State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, College of Materials Science and Engineering, Donghua University, Shanghai 201620, P.R. China
| | - Huaping Wang
- State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, College of Materials Science and Engineering, Donghua University, Shanghai 201620, P.R. China
| | - Qibing Pei
- Department of Materials Science and Engineering, Henry Samueli School of Engineering and Applied Science, University of California, Los Angeles, California 90095, United States
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