Engineering Robust Conductive Hydrogel Sensors with Enhanced Mechanical Properties and Practical Applicability

Conductive hydrogel represents an important component in the modern electronic industry. However, huge challenges still remain because general hydrogels fail to satisfy simultaneous high mechanical properties, excellent conductivity, and real-world tasks, which severely restrain their practical applications. To overcome the challenge, herein, a robust hydrogel PVA/PEI/SG poly(vinyl alcohol)/polyethylenimine/sodium glycinate has been successfully engineered using multiple physical bond networks including the microphase areas of PVA alone and hydrogen bonds among PVA, PEI, and SG. Besides its robust mechanical properties, the hydrogel also exhibits excellent conductivity, sensitivity, and stable signal output capability. Moreover, upon use as a sensor, it can smoothly accomplish real-time tasks like completing an operation of a smartphone to make a call, writing "haust" on a smartphone screen, detecting human joint bending motions, and to-and-fro movement of a mechanical arm. The successful synergy of the attractive high performance enables the hydrogel as a potential conductive device for flexible electronics.