Anisotropic Carbon Aerogel from Cellulose Nanofibers Featuring Highly Effective Compression Stress Transfer and Pressure Sensing

Carbon aerogels with excellent compressibility and resilience are attracting considerable attention in broad application prospects for their reversible resilience and resistance to damage from external stress. It is of great interest to explore green and low-cost carbon aerogels from sustainable resources but remains challenging because of the brittleness of carbon blocks. Herein, inspired by the anisotropic architectures in nature, we propose a bottom-up approach for fabricating an anisotropic carbon aerogel with a 3D lamellar structure from cellulose nanofibers. The aligned and continuous lamellar texture with desirable thickness (142 nm) can effectively transfer stress throughout the 3D network and resist the destruction at high compression, and thus, the carbon aerogel exhibits shape recovery from high compression strain and excellent fatigue resistance. The carbon aerogel can withstand extremely high compression strain (95%) for at least 50 cycles or 50,000 cycles at 50% strain with 84% height retention. Moreover, the excellent mechanical performance, stable 3D lamellar architecture, and high conductivity endow the carbon aerogel with rapid current response and high sensitivity in a wide pressure range (0.002-7 kPa). This study introduces the carbon aerogel as an excellent choice for fabricating the 3D tactile sensor to capture various signals of human motions.