Human soft tissues-like PVA/cellulose hydrogels with multifunctional properties towards flexible electronics applications

Abstract

Conductive hydrogels have attracted significant attention due to their exceptional flexibility, biocompatibility, and promising applications in flexible electronics. Inspired by human soft tissues, robust ionic conductive hydrogels were developed via constructing cellulose-reinforced polyvinyl alcohol networks and precise modulation of zinc ions. The hydrogel exhibits impressive mechanical behaviors (σ = 4.55 MPa, ε = 1293 %) and ionic conductivity as high as 1.17 S/m, ascribed from the multiscale interaction mechanism. These mechanisms include the formation of dense nanofiber networks and nanocrystalline domains, the effects of multiple metal coordination and hydrogen bonds, and the reinforcement of nanocellulose. Moreover, the hydrogel demonstrates a low strain detection limit of 1 % and shows great potential for applications in human health monitoring. Interestingly, based on the principle of Morse code, the hydrogel can be used for information transmission in hazardous environments for emergency signaling. More importantly, when used as an electrolyte in flexible zinc-ion battery, it significantly inhibits zinc dendrite growth and supports stable charge-discharge cycles, making it ideal for small flexible electronic devices. This work presents a biomimetic and sustainable strategy for the rapid fabrication of robust ionic conductive hydrogels, offering advanced applications in flexible electronics.