Stretchable conductive hydrogel with super resistance-strain stability and ultrahigh durability enabled by specificity crosslinking strategy for high-performance flexible electronics

Abstract

Stretchable ionic conductive hydrogels (SICHs) are regarded as one of the indispensable components for flexible electronics desirable to provide stable signal transmission and functional reproducibility. However, the state-of-the-art SICHs demonstrate a narrow resistance-stability range and poor cyclical fatigue reliability due to ion migration limitations and the absence of the molecular design regime. Herein, we present a novel synthetic strategy that utilizes the dynamic Zn-carboxyl physical bonding, adjacent to B-hydroxyl chemical bonding, to realize the “specificity” cross-linking in pectin polymeric networks. This approach significantly extends the resistance-stability range of SICHs, while also providing remarkable longevity. Via “specificity” crosslinking design, the Zn-carboxyl physical bonding, bearing thermodynamically stable and dynamic exchange character, can break the resistance-strain dependence of ionic conductive hydrogel, offering an unprecedented resistance-stability under largely applied strain (300%). Moreover, the B-hydroxyl chemical bonding effectively overcomes the conductivity and mechanical strength trade-off dilemma due to its strong but dynamic feature, realizing the high durability of SICHs. In addition, the extraordinary tolerate harsh environment capacity was achieved by introducing glycerin to form rich hydrogen bonds in the SICHs network, which is crucial for the avoidance of congelation at subzero temperatures and dehydration resulting from the circuit heat. As a stretchable conductive component of deformable electronic devices, the SICH demonstrates extraordinary long life and stable operation. These observations reveal fresh stretchable conductive materials.