Stretchable conductive Janus hydrogel with controllable porous structures for high-performance strain sensing

A stretchable conductive Janus hydrogel with controllable porous structures is developed for highly sensitive monitoring of human motion. The Janus porous structure of the hydrogel is fabricated using patterned single-layer droplets produced by microfluidics as pore-forming templates. The hydrogel possess dual-crosslinked polymeric networks to achieve good stretchability (480%), which allows fully cover the stretching range of human skin (usually <200%). Meanwhile, the hydrogel possess controllable Janus porous structures with local strain/stress enhancement to achieve high sensitivity (GF = 5.2) for strain-sensing. The Janus hydrogel shows fast response for stretching (175 ms) and recovery (170 ms), and good durability (200 cycles at 50% strain). The conductive Janus hydrogel with high sensitivity and good mechanical properties are promising for developing soft wearable sensors in fields such as human health monitoring and human motion detection.