A resilient and lightweight cellulose/graphene oxide/polymer-derived multifunctional carbon aerogel generated from Pickering emulsion toward a wearable pressure sensor

In the new era of competitive smart electronics, the development of compressible multifunctional carbon aerogels is highly needed, but still faces enormous challenges. Here we demonstrate a robust strategy to fabricate multifunctional carbon aerogel via freeze-drying of cellulose nanofibers (CNF) and graphene oxide (GO) co-stabilized Pickering emulsion gel followed by high-temperature annealing. The resulting carbon aerogel exhibits tunable mechanical, hydrophilic and hydrophobic properties due to varying the elemental composition and the pyrolysis of introduced polymers. The carbon aerogel is resilient against high compression strain up to 99 % and has ultralow density (1.82 mg/cm3). The CNF/GO/acrylonitrile butadiene styrene-derived carbon aerogel (CRA)-based sensor has shown desirable sensitivity (17.65 kPa-1), ultralow detection limit of pressure (60 Pa), and fast responsive time (130 ms), which is capable of detecting human activity, identifying spatial pressure distribution, and communicating with smartphones via Wi-Fi. Moreover, the carbon aerogel reveals effective thermal insulation and photothermal conversion performance. These results suggest the great potentials for developing lightweight and compressible carbon aerogels with multiple functions to meet various applications.