Toughening self-healable and recyclable PDMS supramolecular elastomers through an end-capping agent and a metallic crosslinker

Abstract

Elastomers are indispensable in wearable electronics due to their elasticity and flexibility. Among them, poly(dimethylsiloxane) (PDMS) is particularly valued for its nontoxicity and chemical stability. However, conventional PDMS materials lack recyclability and self-healing properties, while most self-healable PDMS materials reported in the literature suffer from insufficient mechanical performance, making it challenging to simultaneously achieve high toughness and efficient self-healing in a single material. To address this, we developed a high-toughness, self-healing, and recyclable PDMS elastomer by introducing 2,4-pentanedione (Hacac) as a capping agent and coordination site, simplifying the synthesis process and enhancing coordination tunability. By incorporating coordination bonds between aluminum metal ions and molecular chain segments, along with the synergistic effect of introducing counter ions, the resulting PUIP-Hac-AlOTf elastomer achieved remarkable mechanical properties (toughness: 48.73 MJ m⁻³) and self-healing efficiency (>95% in 12 hours). Beyond its outstanding mechanical performance, this material demonstrates versatility in wearable applications such as electrocardiogram (ECG) monitoring, hand motion detection, and voice signal sensing. Compared to commercial hydrogel-based electrodes, PUIP-Hac-AlOTf-based patches offer enhanced durability, reusability, and resistance to drying, ensuring stable signal quality over extended use. Its self-healing and recyclable properties, coupled with biocompatibility, make it a groundbreaking solution for intelligent and sustainable healthcare systems.