Zr⁴⁺ Coordination and LiCl Synergistically Enhanced High-Strength Antifreezing Conductive Hydrogels for Wearable Sensing Application

Wearable strain sensors fabricated with ionic conductive hydrogels have broad application prospects in various engineering fields. However, current flexible hydrogel strain sensors still encounter numerous challenges in practical applications, mainly manifested as poor mechanical properties and significant performance degradation at low temperatures. Herein, a multifunctional ionic conductive hydrogel (Glu (Glucan)/P(AM (acrylamide)-co-AA (acrylic acid))-Zr4+/LiCl) was successfully fabricated, which demonstrated outstanding comprehensive performance. Its elongation at break could reach 2213%, the electrical conductivity was 3.086 S/m, and it maintained good flexibility without freezing even at −20 °C. The strain sensor assembled from Glu/P(AM-co-AA)-Zr4+/LiCl hydrogel featured high sensitivity (gauge factor = 7.37), a wide sensing detection range (0% to 500%), and a fast response time (140, 137 ms). Based on these characteristics, the [G1.5/P–Zr0.04]/Li3 hydrogel strain sensor could precisely monitor and distinguish various human physiological activities, including large-scale joint movements (such as elbow flexion and extension and knee joint bending) as well as subtle changes in the throat during speaking. Therefore, the multifunctional performance of the Glu/P(AM-co-AA)-Zr4+/LiCl hydrogel is expected to play a demonstrative role in flexible electronic products.