Eutectic Solvent Gel for Flexible Wearable Sensors

Aiming at the problem of poor stability of traditional hydrogels in flexible sensing applications, in this paper, a ternary eutectic solvent is successfully constructed by using choline chloride, acrylic acid, and ethylene glycol. By introducing α‐methacrylic acid (MAA) monomer and N , N ′‐methylene diacrylamide crosslinking agent, a new type of eutectic solvent gel is prepared by ultraviolet light‐initiated polymerization. The influence of MAA content on the mechanical properties of the gel is systematically studied. When the MAA content is 25 wt%, the comprehensive performance of the gel is the best, the fracture strain reaches 404%, the compressive strength is 1.38 MPa, and the elastic modulus (122 kPa) matched that of human skin. Differential scanning calorimetry confirmes that it still have no crystallization peak from room temperature to −80 °C and have excellent frost resistance. The maximum shear adhesion strength to nine substrates such as metals and plastics reached 343.4 kPa. The sensing test showes that the gel have a significant sensitivity (gauge factor = 1.64–4.06) within the strain range of 0%–320%, and could stably monitor human joint movements. This work provides a new strategy for developing high‐performance flexible wearable sensors suitable for extreme environments.