Ultrastretchable and Wireless Bioelectronics Based on All‐Hydrogel Microfluidics

Hydrogel bioelectronics that can interface biological tissues and flexible electronics is at the core of the growing field of healthcare monitoring, smart drug systems, and wearable and implantable devices. Here, a simple strategy is demonstrated to prototype all‐hydrogel bioelectronics with embedded arbitrary conductive networks using tough hydrogels and liquid metal. Due to their excellent stretchability, the resultant all‐hydrogel bioelectronics exhibits stable electrochemical properties at large tensile stretch and various modes of deformation. The potential of fabricated all‐hydrogel bioelectronics is demonstrated as wearable strain sensors, cardiac patches, and near‐field communication (NFC) devices for monitoring various physiological conditions wirelessly. The presented simple platform paves the way of implantable hydrogel electronics for Internet‐of‐Things and tissue–machine interfacing applications. Stretchable and wireless bioelectronics based on all‐hydrogel microfluidics and liquid metal are fabricated by combining a two‐step crosslinking mechanism and a laser‐engraving method. The perfused liquid metal in hydrogel microchannels form tailor‐designed conductive networks of hydrogel bioelectronics. The applications of all‐hydrogel‐based bioelectronics are demonstrated as wearable and potentially implantable sensors for monitoring physiologically relevant signals wirelessly.