Silver Nanowire–Bacterial Cellulose Composite Fiber-Based Sensor for Highly Sensitive Detection of Pressure and Proximity

• Published in: ACS nano 2020-11, Vol.14 (11), p.15428-15439
• Main Authors: Guan, Fangyi, Xie, Yu, Wu, Hanxiang, Meng, Yuan, Shi, Ye, Gao, Meng, Zhang, Ziyang, Chen, Shiyan, Chen, Ye, Wang, Huaping, Pei, Qibing
• Format: Article
• Language: English
• Subjects: Cellulose; Electric Conductivity; Humans; Nanowires; Silver; Wearable Electronic Devices
• ISSN: 1936-0851; 1936-086X
• DOI: 10.1021/acsnano.0c06063

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 (