Anisotropic Layered Cellulose Nanofiber-Based Carbon Aerogels for High-Performance Pressure Sensing

Flexible piezoresistive sensors have broad application prospects in fields such as health monitoring and human-machine interaction. To address the challenges of traditional aerogel sensors, including weak mechanical properties, low sensitivity, and poor fatigue resistance, this study constructed a hierarchical biomass-based carbon aerogel (CNF/rGO/CS-B). The material was fabricated using cellulose nanofibers (CNF) as the matrix, graphene oxide (GO) as the precursor for the conductive component, and chitosan (CS) as a reinforcing component through bidirectional freezing, chemical cross-linking, and high-temperature carbonization. The effects of CS addition and freezing modes on the mechanical and sensing properties of the aerogels were systematically investigated. The results indicate that, owing to the synergistic effects of the ordered lamellar structure formed by bidirectional freezing and the stable cross-linked network constructed with the participation of CS, the aerogel exhibits excellent mechanical properties, including a compressive strength of 198.8 kPa at 60% strain and outstanding fatigue resistance, with 90% stress retention after 500 cycles at 40% strain. When used as a pressure sensor, it demonstrates high sensitivity (3.06 kPa −1 ) and excellent durability, with signal attenuation of less than 5% over 1500 compression cycles. The sensor can accurately monitor various human motions, such as finger bending and swallowing, providing a promising strategy for the development of high-performance wearable electronic devices.