A Recyclable, Ecofriendly, and Biofriendly Biomass-Based Elastomer via the Nanoactivation Effect of Liquid Metal for Electronic Skin

The integration of liquid-metal (LM) droplets within the soft polymer presents an attractive material for developing electronic skin (E-skin) with diverse and fascinating properties. However, enhancing its friendly performances (the recyclable, ecofriendliness, and biofriendliness) to enable large-scale applications remains a challenge. Here, we fabricate a natural polymer-based composite through embedding LM nanodroplets into cellulose film extracted from corn stalks, which exhibits a variety of friendly performances including eco-degradability, recyclability, biocell compatibility, biotissue compatibility, and high-value utilization of agricultural waste. Under the nanoactivation effect of LM, the crystalline region in film undergoes structure upgrading, opening the cellulose molecular chains to an amorphous state and inducing a spontaneously formed dynamic network through physical cross-links of interchain hydrogen bonds. Consequently, the composite is conferred with outstanding softness and resilience (modulus of 0.64 MPa, stretchability of 827.1%, and toughness of 14.55 MJ m^-3), breaking the conventional perception of cellulose film as rigid and inelastic. Finally, the piezocapacitive sensor array manufactured from our composite has been implemented in an intelligent sensing system to recognize sitting postures and letter graphics with high accuracy, becoming an important milestone toward advancing the next-generation of friendly E-skin.