Flexible Wearable Sensor Based on a Chemically Cross‐Linked PAALi / EG /Zn( CF ₃ SO ₃ ) ₂ Anti‐Freeze Ion‐Conductive Hydrogel

Conductive hydrogels can serve as important carrier materials for flexible strain sensors, demonstrating promising application prospects in the field of flexible wearable sensors. Nevertheless, conventional conductive hydrogels frequently have subpar mechanical, electrical, and freezing resistance qualities, which significantly restricts their usefulness in wearable sensors. Using a free radical polymerization process, ethylene glycol (EG) was added as an antifreeze agent and Zn(CF 3 SO 3 ) 2 as an ionic conductive filler to the polyacrylate lithium (PAALi) hydrogel matrix to create an anti‐freezing ion‐conductive hydrogel with a chemically cross‐linked network of PAALi/EG/Zn(CF 3 SO 3 ) 2 . The PAALi/EG/Zn(CF 3 SO 3 ) 2 (7.5 wt%) hydrogel has an elongation at break of 803%, a tensile strength of 0.499 MPa, and a conductivity of 1.534 S/m at room temperature. It retains outstanding flexibility and a conductivity of 1.084 S/m at −24°C. This hydrogel also exhibits outstanding adhesion, self‐healing qualities, fatigue resistance, moisture retention, and anti‐swelling capabilities. It has a wide detection range, great sensitivity, and very little hysteresis for a wearable strain sensor. In addition to small deformations like frowning and swallowing, this wearable strain sensor can precisely track joint movements like finger and wrist bending. It has encouraging potential for use in wearable sensing applications.