A Biomimetic Lotus Root-Inspired Dual-Network Hydrogel Wearable Strain Sensor for Human Motion and Intelligent Traffic Monitoring

In this study, we developed a novel strain-sensing polyacrylamide (PAM) and sodium alginate (SA)/Cellulose/Pectin-Ca2+ (PSCP-Ca2+) composite hydrogel by integrating cellulose-pectin reinforcing networks into a dual-network matrix composed of PAM and SA, with Ca2+ ions serving as both structural cross-linkers and charge carriers. The PSCP-Ca2+ hydrogel demonstrated excellent mechanical properties (630 kPa stress, 1700% strain, and 5.8 MJ/m3 toughness), good self-healing properties, and high electrical conductivity (0.89 S/m). When employed as a flexible strain sensor, it exhibited a high gauge factor in both tension (GF = 3.74) and compression (GF = 6.48), a broad response range (0–1000% strain), and excellent fatigue resistance (2000+ tensile cycles and 500+ compressive cycles). This work provides valuable insights for designing high-performance hydrogel sensors and advances the practical implementation of flexible electronics in smart wearable devices and intelligent transportation systems.