Flexible pressure sensor enhanced by polydimethylsiloxane and microstructured conductive networks with positive resistance-pressure response and wide working range

Abstract

Improving the performance of flexible pressure sensors has received increasing attention owing to their numerous applications in advanced technologies. However, many approaches that yield exceptional performance often involve complex manufacturing processes and high costs, which are not conducive to the large-scale production and application of flexible pressure sensors. Therefore, this paper presents a simple and efficient method, combining a pre-strain strategy with polydimethylsiloxane infiltration, for manufacturing flexible pressure sensors with a wide working range, enhanced sensitivity, and good stability. Sensors fabricated using this method exhibit an improved sensitivity of 0.0331 kPa−1 within the broad working range of 0.11–1250 kPa, ultra-fast response time of 8 ms, and good stability as well as repeatability over 2500 cycles of 15% strain loading. The sensing mechanism and resistance model of the sensor were investigated, and a sensing model based on the tunneling effect and resistance model was developed. The coefficient of determination between the model and the experimental data exceeded 0.99, thereby verifying its validity. Finally, a sensor array was tested to locate the pressure and recognize the object shape within a large pressure range, demonstrating its potential applications in engineering fields with high-pressure requirements. This study provides a reference for the simple and cost-effective manufacturing of advanced flexible sensors and offers valuable insights into the large-scale production of flexible sensors.