Skin-like mechanoresponsive self-healing ionic elastomer from supramolecular zwitterionic network

Stretchable ionic skins are intriguing in mimicking the versatile sensations of natural skins. However, for their applications in advanced electronics, good elastic recovery, self-healing, and more importantly, skin-like nonlinear mechanoresponse (strain-stiffening) are essential but can be rarely met in one material. Here we demonstrate a robust proton-conductive ionic skin design via introducing an entropy-driven supramolecular zwitterionic reorganizable network to the hydrogen-bonded polycarboxylic acid network. The design allows two dynamic networks with distinct interacting strength to sequentially debond with stretch, and the conflict among elasticity, self-healing, and strain-stiffening can be thus defeated. The representative polyacrylic acid/betaine elastomer exhibits high stretchability (1600% elongation), immense strain-stiffening (24-fold modulus enhancement), similar to 100% self-healing, excellent elasticity (97.9 +/- 1.1% recovery ratio, <14% hysteresis), high transparency (99.7 +/- 0.1%), moisture-preserving, anti-freezing (elastic at -40 degrees C), water reprocessibility, as well as easy-to-peel adhesion. The combined advantages make the present ionic elastomer very promising in wearable iontronic sensors for human-machine interfacing.

Automated summary

The stretchable ionic elastomer demonstrated in the study exhibits high stretchability, immense strain-stiffening, good self-healing ability, excellent elasticity, high transparency, anti-freezing properties, water reprocessibility, and easy-to-peel adhesion, making it very promising for use in wearable electronic sensors for human-machine interfacing.