Robust and superelastic spider web-like polyimide fiber-based conductive composite aerogel for extreme temperature-tolerant linear pressure sensor

Abstract

Pressure sensors represent the cornerstone of artificial tactile sensing. Extensive research has been conducted on high-performance pressure sensors; however, the realization of high sensitivity, wide linear response range, and wide working temperature range remains a tremendous challenge. Here, triethylamine was innovatively applied to achieve the homogeneous dispersion of hydrophobic polyimide fibres (PIFs) in a carbon nanotube (CNT) aqueous dispersion without deteriorating the structure of the fibres, and a robust and superelastic spider web-like PIF/CNT conductive composite aerogel was developed using the freeze-drying and thermal imidization technique for a pressure sensor with a wide linear sensing range (0.01–53.34 kPa), ultralow detection limit (10 Pa), high sensitivity (0.507 kPa−1), fast response/recovery time (85/80 ms), stable fast compression response (500 mm min−1), and excellent cyclic fatigue resistance (5000 times). Finite element analysis indicates that the hierarchical fibrous network induces a significant linear variation in the contact area between adjacent conductive fibres upon external pressure and contributes to the excellent linear sensing capacity. The pressure sensor is demonstrated to be applicable in human physiology and motion signal detection, electronic skin, and intelligence control. Notably, it also exhibits amazing sensing stability and thermal insulation under extreme temperature conditions, demonstrating much promise for emerging applications such as the sensing unit for space suits and inflatable structures for future lunar/Mars habitats. This work provides a simple but powerful strategy for developing next-generation linear pressure sensors.