Conductive and superhydrophobic F-rGO@CNTs/chitosan aerogel for piezoresistive pressure sensor

Piezoresistive pressure sensors with high sensitivity, fast response, and simplified signal collection play an important role in a wide variety of fields. However, most of them are water-sensitive and easily attacked by water, leading to serious signal distortion in practical application. Herein, we fabricated a conductive and superhydrophobic 1H,1H,2H,2H-perfluorooctyltriethoxysilane (FAS) modified reduced graphene oxide@carbon nanotubes/chitosan (F-rGO@CNTs/CS) aerogel for piezoresistive pressure sensor. Benefiting from the porous structure of aerogel and the synergy of CNTs and rGO, the aerogel sensor achieved high sensitivity and fast response. Moreover, the sensor maintained a stable electrical resistance response after 1000 loading-unloading cycles. Importantly, owing to the rough structure constructed by CNTs and multi-pores and the low surface energy of FAS, the sensor possessed superhydrophobic property with a high water contact angle of 154 degrees, and exhibited remarkable water repellency even during compression process. In addition, the sensor was successfully applied for detecting human behaviors from small-scale muscle movements to large-scale body motions. Our findings provide a new direction to fabricate functional and high-performance piezoresistive pressure sensor for various applications even under water or wet environment.