Reversible Wet‐Adhesive and Self‐Healing Conductive Composite Elastomer of Liquid Metal

Abstract Stretchable conductors with the combination of high elasticity and electric conductivity have long been pursued in soft electronics. Liquid metals (LMs), whose mechanical properties match well with the elastomeric matrix, have been successfully applied in soft robotics, electronic skins and wearable devices. But it remains challenging to develop conductive composite elastomers of LMs with reversible adhesion and self‐healing. Herein, EGaIn droplets are uniformly dispersed into elastomer, which contain dynamic disulfide to endow the composite elastomer with thermal processability, recyclability, reversible wet adhesion, and self‐healing. With the EGaIn content of ≥40 vol.%, the resultant composite elastomer shows the electric conductivity of 1.3 × 104 S m −1 , self‐healing in 8.0 h, and reversible wet adhesion strength up to 670 kPa after curing for 2.0 h. When serving as conductive adhesive, it can easily adhere to the metal electrode to light up the LED even when stretched to 50%. When serving as self‐adhesive bioelectrode, it can also detect human electromyography signals. Thus, not only may this study provide a new platform of designing self‐adhesive, self‐healing, and conductive composite elastomers of liquid metals, but their reversible wet adhesion and self‐healing also promise the facileness of building damage‐endurable soft electronics and applying to human–machine interfaces.