Flexible pressure sensor with a wide pressure measurement range and an agile response based on multiscale carbon fibers/carbon nanotubes composite

Abstract

As an important branch of wearable electronics, flexible pressure sensors have aroused extensive concern owing to their wide range of applications, such as human health monitoring, human–machine interfaces, and artificial intelligence. Therefore, higher requirements are put forward for the dominating performances of sensitivity, pressure measurement range and response time about flexible pressure sensors. Here, we present a flexible piezoresistive pressure sensor (FPPS) based on carbon fibers (CFs)/carbon nanotubes (CNTs)-polydimethylsiloxane (PDMS) composite and interdigital electrode, which displays a wide measurement range of stress and an agile response at loading and unloading forces. Due to the cooperating advantages of the multiscale carbon fillers, the microstructures on the surface of the piezoresistive film and the interdigital electrode, the FPPS reveals a wide measurement range (from 0 kPa to 185.9 kPa) and a high sensitivity (2.02 kPa‐1 at pressures between 36 Pa and 50.2 kPa). Meanwhile, owing to the carefully designed trilateral double-sided adhesive structure, the FPPS exhibits an agile response (response time of 43 ms) and a stable output (test time of 9000 s). Moreover, the FPPS is capable of identifying clapping and trampling motions, demonstrating its effectiveness as a flexible sensing unit. The novel pressure sensor was integrated with additional software and hardware to realize a real-time pressure acquisition and display system, providing a potential use of the device in an intelligent industry application.