Bioinspired Ionic Elastomer with Skin-Like Piezo-Ionic Dynamics Enabled by a Self-Confined Multi-Interaction Network

Abstract

Soft ionic elastomers have attracted considerable research interest in mimicking the multiple functions of human skin. However, these ionic elastomers struggle to simultaneously achieve controllable ion dynamics and other essential performance, such as self-healing ability and appropriate mechanical robustness. Herein, bioinspired by Piezo proteins and integrins in human skin, thioctic acid (TA)-derived ionic elastomers with skin-like piezo-ionic dynamics are fabricated via a multi-confined interaction network. This bionic network is constructed by introducing a diene comonomer and lithium salt filler into polysulfides (poly (TA)), generating many dynamic interactions (various hydrogen bonds and lithium bonds). These dynamic interactions can bind ions to the polysulfides and be destroyed under external pressure stimulation, achieving controllable ion pumping behavior. This unique design concept enables these ionic elastomers to selectively respond to pressure (the optimal sample exhibits 152 times signal intensity with a sensitivity of 49.53-1.13 kPa⁻¹), along with leak prevention, recyclability, and degradability. Besides, these interactions also serve as sacrificial bonds and self-healing sites to synergistically enhance all aspects of performance, yielding a high modulus of 2.47 MPa and outstanding self-healing efficiency of 98%. It is believed that this work could create a new approach for utilizing sustainable materials in next-generation “green” flexible sensors.