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

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 biocom-patibility, 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 carbon-ization. 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 me-chanical stability (3000 compressing cycles), and a quick response/recovery time (120/90 ms). The piezor-esistive 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 degrees C and-196 degrees C). The prepared piezoresistive sensor is expected to have versatile applications in next-generation spatial pressure monitoring, wearable electronics, and sound visualization.