Polyimide/Carboxylated Multi-walled Carbon Nanotube Hybrid Aerogel Fibers for Fabric Sensors: Implications for Information Acquisition and Joule Heating in Harsh Environments

Polymeric hybrid sensors have garnered great interest in health monitoring, human–computer interaction, and soft robotics for their lightweight, flexibility, and feasible fabrication process. However, polymeric hybrid sensors suitable for harsh environments remain a considerable challenge, limiting further application. Herein, polyimide (PI)/carboxylated multi-walled carbon nanotube (c-MWCNT) hybrid aerogel fibers with a micro-porous structure were fabricated via wet-spinning and chemical thermal imidization. The fabricated PI/c-MWCNT hybrid aerogel fibers' conductivity and the change of current in response to the bending degree were tested, in which the relative current change achieved 4.78% with a bending degree of 150°. The fibers possessed a density of 0.41 ± 0.06 g/cm3, a conductivity of 17.8 ± 2.9 μS/m, and a tensile strength of 13.0 ± 1.1 MPa. In addition, they exhibited excellent heat/cold durability, whose decomposition temperature, cold resistance, and service life were 367 °C, −196 °C, and 300 cycles, respectively. Furthermore, the fabric sensor woven with PI/c-MWCNT hybrid aerogel fibers demonstrated two sensitivity stages of stage 1 (S1) = 6.04 and stage 2 (S2) = 0.55 under various pressures. Besides, it could be heated to 62 °C at a voltage of 30 V in 90 s with a changing resistance. The above properties demonstrate that the as-prepared fabric sensor exhibited great application potential for information acquisition and joule heating in harsh environments.