Bio‐Inspired Conductive Hydrogels with High Toughness and Ultra‐Stability as Wearable Human‐Machine Interfaces for all Climates

Abstract

Abstract Drawing inspiration from Salicornia , a plant with the remarkable ability to thrive in harsh environments, a conductive hydrogel with high toughness and ultra‐stability is reported. Specifically, the strategy of pre‐cross‐linking followed by secondary soaking in saturated salt solutions is introduced to prepare the PAAM‐alginate conductive hydrogel with dual cross‐linked dual network structure. It allows the alginate network to achieve complete cross‐linking, fully leveraging the structural advantages of the PAAM‐alginate conductive hydrogel. The highest tensile strength of the obtained conductive hydrogel is 697.3 kPa and the fracture energy can reach 69.59 kJ m −2 , significantly higher than human cartilage and natural rubbers. Specially, by introducing saturated salt solutions within the hydrogel, the colligative properties endow the PAAM‐alginate conductive hydrogel with excellent water retention and anti‐freezing properties. The prepared conductive hydrogels can work stably in an ambient environment for more than 7 days and still maintain good mechanical behavior and ionic conductivity at −50 °C. Benefiting from the excellent comprehensive performance of conductive hydrogels, wearable human‐machine interfaces that can withstand large joint movements and are adapted for extreme environments are prepared to achieve precise control of robots and prostheses, respectively.