Deep eutectic solvent-regulated polyacrylamide/alginate/PEDOT:PSS conductive hydrogels with improved low-temperature performance

Conductive hydrogels for wearable strain sensors usually suffer from water crystallization and polymer network rigidification under subzero conditions, resulting in reduced flexibility and compromised sensing stability. To address this challenge, a deep eutectic solvent (DES)-regulated sodium alginate/polyacrylamide (SA/PAM) double-network hydrogel integrated with PEDOT:PSS was developed to construct a mixed ionic–electronic conductive network. Unlike previously reported single-network PAM-based DES hydrogels, the present SA/PAM double-network architecture combines DES-mediated dynamic interactions with PEDOT:PSS-based electronic conduction, enabling synergistic enhancement of antifreezing capability, mechanical robustness, and electromechanical sensing performance. The optimized 30DES-SPP hydrogel exhibited a tensile strength of 0.38 MPa and an elongation at break of 1767% at room temperature. It also achieved a gauge factor (GF) of 8.51 at 500% strain. After storage at −25 °C, the hydrogel maintained an elongation at break of 1514%, demonstrating excellent low-temperature tolerance and flexibility. In addition, stable and repeatable electrical responses were observed during repeated deformation. The hydrogel was successfully applied to human motion monitoring, Morse code communication, and handwriting pressure recognition. This work presents an effective strategy that integrates DES-regulated double-network reinforcement with conductive network engineering, offering promising potential for wearable sensing devices and flexible human–machine interfaces under subzero conditions. Download: Download high-res image (147KB) Download: Download full-size image