Robust, Self-Healable Siloxane Elastomers Constructed by Multiple Dynamic Bonds for Stretchable Electronics and Microsystems

Abstract

Self-healable siloxane elastomers have recently attracted much interest in research for applications in flexible electronic devices. However, it remains a challenge for self-healable siloxane elastomers to realize good mechanical and rapid high-efficiency self-healable properties at room temperature. Herein, a desirable siloxane polymer elastomer was designed by the synergy of multiple dynamic bonds. In this self-healable system, the disulfide bonds as sacrificial bonds and hydrogen bonds as weak bonds could endow elastomers with rapid self-healability and high stretchability. Whereas, the Fe-coordination bonds could tune the robustness of a siloxane elastomer. Due to the synergy of multiple dynamic bonds, the self-healable PDMS-SS-DOPA1-Fe2 elastomer achieved high stretchability of 1100%, tensile stress of 1.11 MPa, and high self-healable efficiency of 96% (within 3 h). Moreover, after healing for 3 min at room temperature, the damaged siloxane elastomers were able to obtain a breaking strain of 250% and tensile stress of 0.5 MPa. As a proof of concept, based on elastomer films integrated with liquid metal alloy EGaIn (eutectic gallium–indium), stretchable electrodes and strain sensors were subsequently developed, opening the avenue to potential applications in flexible electronics and microsystems.