Iron-Adjustable Compressible Elastic Chitosan-Derived Carbon Aerogel with Wide-Range Linear Sensitivity and Super Sensing Performances for Wearable Piezoresistive Sensors

Ultra-light elastic carbon aerogels with high compressibility have broad application prospects in wearable devices. Especially, they are ideal materials for fabricating flexible piezoresistive sensors. In this paper, an ultra-light carbon aerogel was successfully fabricated using freeze-drying and carbonization of the solution containing chitosan (CS), polyimide (PI), and FeCl3·6H2O. Owing to the interplay interaction between CS and PI and the adjustment of the FeCl3 concentration, this carbon aerogel with compact, continuous, ordered, layered structure shows a wide range of excellent sensing properties (10.28 kPa–1 and 0–6 kPa), remarkable long-term stability (1000 cycles), and outstanding mechanical properties (withstand up to 95% compression strain and 1000 cycles compression under 50% strain without deformation). In addition, the carbon aerogel can be bent to detect different angular changes. These advantages mentioned above allow carbon aerogel to be wildly used to detect human movement and biological signals.