Flexible piezoresistive sensors based on porous PDMS/CB composite materials prepared by the solvothermal method

Flexible piezoresistive sensors (FPS) have drawn great attention in electronic skin, wearable electronics and real-time health monitoring. In this work, the porous polydimethylsiloxane (PDMS)-carbon black (CB) (abbreviated as PDMS/CB) composite materials were prepared by a solvothermal method using spherulite NaCl(s) templates as pore-forming agents. The porosity of porous PDMS/CB composite materials was tuned by changing the NaCl(s) from 0 wt% to 20 wt%. FPS based on porous PDMS/CB was designed and prepared. The electrical and mechanical properties of porous PDMS/CB composite materials as well as performance of FPS were studied. With 18 wt% NaCl, PDMS/CB sensor exhibits a large sensitivity of 0.52 kPa −1 in the pressure ranges of 0.026–100 kPa, a high gauge factor of 346.1, a fast response of 46 ms, a low detection limit of 26 Pa as well as superior cyclic stability over 7500 cycles. In addition, PDMS/CB sensor was used for human motion monitoring to verify its sensing functionality.