Wet-Adhesive Hydrogel with Antiswelling Capacity for Strain Sensing.

The development of functional hydrogels with wet adhesion strength and antiswelling properties is crucial for applications ranging from biomedicine to wearable electronics but remains difficult to realize. Herein, we developed a high-performance TA/PAAc/EMA/C-CNT (TPEC) hydrogel via a solvent displacement process. The TPEC hydrogel showed no observable swelling behavior even after 8 days of immersion in a water bath, demonstrating its excellent antiswelling property. The TPEC hydrogel possesses strong adhesive strength in the underwater environment, allowing it to adhere firmly to rigid substrates and moving fingers, and also acts as a sealing material to prevent liquid leakage underwater. In addition, the TPEC hydrogel also demonstrated improved mechanical properties, good conductivity, and antimicrobial properties. Finally, exploiting its multifunctional properties, the resulting TPEC hydrogel is utilized as a flexible wearable strain sensor for monitoring body motion in both air and water environments. This work is expected to open up new opportunities for developing future generations of high-performance adhesive hydrogels for use in wet environments.