Highly stretchable, conductive, and self-adhesive starch-based hydrogel for high-performance flexible electronic devices

To achieve the green and sustainable development of environment, biocompatible hydrogels with exceptional ionic conductivity and flexibility are highly desired for intelligent and wearable sensors. However, it remains a great challenge to obtain biopolymer hydrogel-based sensors with high transparency, excellent mechanical properties, and good adhesion ability simultaneously. Herein, starch/polyacrylamide double-network hydrogel is achieved to endow the multifunctionality of traditional hydrogel sensor. Specifically, the resultant hydrogel sensor exhibits wide strain detection range of 2580 %, fast response time of 120 ms, high conductivity of 31.9 mS & sdot;m- 1, superior sensitivity, remarkable fatigue resistance of 1350 cycles. In addition, multiple hydrogen bonding endows starch/polyacrylamide hydrogel with high mechanical properties and high transparency. Owing to these merits, the hydrogel sensor is capable of discriminating different human motions. Notably, the ionic conducting hydrogels could be employed as single-electrode TENGs for energy harvesting. The multifunctionality and biocompatibility of starch-based hydrogel sensor may offer an inspiration for the future development of nextgeneration sustainable and wearable electronics.