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

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.