Compressible, Elastic, and Pressure-Sensitive Carbon Aerogels Derived from 2D Titanium Carbide Nanosheets and Bacterial Cellulose for Wearable Sensors

Compressible and elastic carbon aerogels (CECAs) hold great promise for applications in wearable electronics and electronic skins. MXenes, as new two-dimensional materials with extraordinary properties, are promising materials for piezoresistive sensors. However, the lack of sufficient interaction among MXene nanosheets makes it difficult to employ them to fabricate CECAs. Herein, a lightweight CECA is fabricated by using bacterial cellulose fiber as a nanobinder to connect MXene (Ti3C2) nanosheets into continuous and wave-shaped lamellae. The lamellae are highly flexible and elastic, and the oriented alignment of these lamellae results in a CECA with super compressibility and elasticity. Its ultrahigh structural stability can withstand an extremely high strain of 99% for more than 100 cycles and long-term compression at 50% strain for at least 100 000 cycles. Furthermore, it has a high sensitivity that demonstrates not only an ultrahigh linearity but also a broad working pressure range (0-10 kPa). In particular, the CECA has a high linear sensitivity in almost the entire workable strain range (0-95%). In addition, it has very low detection limits for tiny strain and pressure. These features enable the CECA-based sensor to be a flexible wearable device to monitor both subtle and large biosignals of the human body.