Flame‐Retardant PEDOT:PSS/LDHs/Leather Flexible Strain Sensor for Human Motion Detection

Flexible piezoresistive sensors have demonstrated great potential in human-motion-detection applications. However, it still remains a challenge to fabricate strain sensors with high sensitivity, broad sensing range, and good linear response to strain. In this report, a simple and scalable fabrication strategy is developed to construct high performance strain sensors by using leather as the substrates to filtrate poly(3,4-ethylenedioxythiophene): poly(4-styrenesulfonate) (PEDOT:PSS) modified layered double hydroxides (LDHs) suspensions. The naturally aligned collagen fibers in leather enable size selection for the 2D conductive materials and as such dual-conductive pathways are effectively formed on the surface and in the matrix of leather. Due to the unique design of conductive networks, the prepared sensor possesses high gauge factor (maximum value of 2326.84), tunable strain range (0-70%), fast tensile response time (160 ms), and good stability in 1000 stretching-relaxing/compression-relaxing cycles, making it suitable for various human motion detections including coughing and large-scale motions of joint bending. In addition, the incorporated LDHs is a non-toxic flame retardant, which is helpful to reduce electronic fire risk and can bring added value to the sensor.