A highly conductive and stretchable wearable liquid metal electronic skin for long-term conformable health monitoring

Conventional rigid electronics are usually unconformable with soft skins and tend to fail in accurate physiological monitoring and precise treatment. Electronic skins (e-Skins) made by conductive and stretchable materials offer mechanical compliance for fabricating flexible and conformable wearables. Compared to common organic or inorganic conductive materials, gallium-based liquid metals alone own superior conductivity and compliance. Here, we demonstrate a highly conductive and stretchable electronic skin with liquid metal circuits (LMCs) embedded in silicone rubber film, which are functionalized for physiological signals monitoring. Through the designs of serpentine structure, LMCs maintained good electrical conductivity and functionality under over 100% strain. Also, a wearable electrocardiogram (ECG) recording device was fabricated and tested. The device was able to acquire steady signals during real-time measurement of physical activities. The proposed liquid metal e-Skin can be further extended to conformable bio-integrated healthcare devices and intelligent health monitoring networks.