Engineered structural carbon aerogel based on bacterial Cellulose/Chitosan and graphene Oxide/Graphene for multifunctional piezoresistive sensor

Abstract

Piezoresistive sensors are highly desired in a wide variety of fields in health monitoring, human–machine interaction, robot sensing, and so on. Developing engineering-architected piezoresistive sensors with biocompatibility, high sensitivity, and mechanical robustness is one of the hot research fields. Here, a high-performance hybrid carbon aerogel is constructed from bacterial cellulose, chitosan, graphene oxide, and graphene based on synergistic electrostatic interaction and hydrogen bonding through unidirectional freeze-casting and carbonization. The carbon aerogel, characterized by its unique lamellar and fibrous alternating structure, mirrors the stability of a well-constructed “bridge”. In this analogy, the layer functions as a steady “girder”, while the fiber emulates indispensable “stay cable”. The ordered microstructure contributes to uniform stress transfer, yielding a carbon aerogel-based sensor that exhibits high piezoresistive linear sensitivity (150 kPa−1), outstanding mechanical stability (3000 compressing cycles), and a quick response/recovery time (120/90 ms). The piezoresistive sensor detects real-time human physiological signals and effectively distinguishes subtle and different acoustic signals, enabling sound visualization. Also, it can work well in extreme conditions (200 °C and −196 °C). The prepared piezoresistive sensor is expected to have versatile applications in next-generation spatial pressure monitoring, wearable electronics, and sound visualization.