Superelastic bamboo cellulose nanofiber based carbon aerogel with layered network microstructure for high sensitivity piezoresistive sensor.

Carbon aerogels, characterized by their high porosity and superior electrical performance, present significant potential for the development of highly sensitive pressure sensors. However, facile and cost-effective fabrication of biomass-based carbon aerogels that concurrently possess high sensitivity, high elasticity, and excellent fatigue resistance remains a formidable challenge. Herein, a piezoresistive sensor with a layered network microstructure (BCNF-rGO-CS) was successfully fabricated using bamboo nanocellulose fiber (BCNF), chitosan (CS), and graphene oxide (GO) as raw materials. The fabrication process involved directional ice-crystal growth and mild hydrothermal reduction methods where the directional ice-crystal growth technique imparted a stable network-like pore structure, while the mild hydrothermal reduction method ensured electrical conductivity without compromising the original properties of the CNF. Taking advantage of the stress transfer properties of the cross-linked network structure, BCNF-rGO-CS exhibited exceptional reversible compressibility (sustaining 80 % strain), high fatigue resistance (10,000 cycles at 60 % strain), and high stress retention (84.6 %) over long-term cycling. Furthermore, the BCNF-rGO-CS sensor exhibited notable low-pressure sensitivity, excellent response time (66/76 ms), and it was capable of responding to ultra-low pressures of 10 Pa. Based on these favorable characteristics, the piezoresistive sensor holds promising prospects for applications in body motion detection, health monitoring, and flexible electronic-skin.