High-Efficiency, Self-Healing Elastomer via Dynamic Boronic Ester Bond Density Regulation for Joint Motion Monitoring.

Elastomer-based flexible and stretchable sensors have attracted considerable research interest for promising applications in areas, such as human-machine interfaces, physiological monitoring, and soft robotics. Despite the typical trade-off between transparency, mechanical strength, and self-healing in elastomers, which is rooted in conflicting requirements for molecular chain mobility, impeding this broad application prospects in wearable devices and the conformable electronics field. This work demonstrates a polyborosiloxane/polydimethylsiloxane interpenetrating network (PBS/PDMS IPN) that successfully reconciles these properties. The resulting multifunctional elastomer exhibits both effective self-healing (97.8% recovery of tensile strength in 15 min under 1 psi) and a transmittance up to 93%. The energy dissipation imparted by high-molecular-weight hydroxy-terminated PDMS (PDMS-OH) further enhances adhesion, granting the multifunctional elastomer superior bonding performance. The multifunctional elastomer is integrated with eutectic gallium-indium (EGaIn) to form a stress sensor, which enables high-accuracy human motion monitoring, showcasing its potential for advanced wearable medical sensors.