A biomimetic polyimide aerogel applied in capacitive sensors with potential for high-temperature sensing application

With the rapid development of aerospace engineering, geological exploration and intelligent fire protection, increasing attention has been directed toward sensing technologies for high temperature environments. In this case, flexible mechanical sensors still face challenges such as high temperature resistance and temperature drift. In this study, a novel biomimetic material was proposed to improve thermal resistance and solve the problem of high temperature drifting of sensors. Drawing inspiration from the structure of cuttlebone, a bioinspired anisotropic polyimide aerogel (BA-PA) using polyimide has been developed with bidirectional freezing method. The BA-PA exhibits excellent thermal stability and good fatigue resistance, making it an ideal dielectric layer for capacitive sensors. BA-PA sensor demonstrates stable force-electrical response and an ultrafast response time (∼10 ms). Meanwhile, the sensor operates stably with wide range from 20°C to 340 °C. Finally, the BA-PA sensor was demonstrated to possess the capability of achieving both tactile and gesture sensing. This work expands the application scope of polyimide aerogels and provides a new strategy for sensing under high-temperature environment.