Polyimide aerogel-based capacitive pressure sensor with enhanced sensitivity and temperature resistance

The development of intelligent electronic power systems necessitates advanced flexible pressure sensors. Despite improved compressibility through surface micro-structures or bulk pores, conventional capacitive pressure sensors face limitations due to their low dielectric constant and poor temperature tolerance of most elastomers. Herein, we constructed oriented polyimide-based aerogels with mechanical robustness and notable changes in dielectric constant under compression. The enhancement is attributed to the doping of surface-modified dielectric nanoparticles and graphene oxide sheets, which interact with polymer molecular chains. The resulting aerogels, with their excellent temperature resistance, were used to assemble high-performance capacitive pressure sensors. The sensor exhibits a maximum sensitivity of 1.41 kPa−1 over a wide working range of 0-200 kPa. Meanwhile, the sensor can operate in environments up to 150°C during 2000 compression/release cycles. Furthermore, the aerogel-based sensor demonstrates proximity sensing capabilities, showing great potential for applications in non-contact sensing and extreme environment detection.