Liquid metal integrated cellulose nanocrystal/polyacrylic acid dual-network hydrogel towards high-performance wearable sensing and electromagnetic interference shielding

Abstract

Simultaneously achieving high electrical conductivity, exceptional mechanical strength, and strong adhesion in hydrogel sensors remains a significant challenge. In this study, a dual-network cellulose nanocrystal/polyacrylic acid (CNC/PAA) conductive hydrogel integrated with liquid metal, Ti₃C₂T_x MXene, and lithium chloride (LiCl) as conductive fillers was developed. With superior electrical conductivity (3.17 S/m), remarkable strain tolerance (1381% strain, strength of 142.8 kPa), and excellent adhesion (24.72 kPa), the conductive hydrogel sensor exhibits high sensitivity (gauge factor = 3.28 across a 1000% strain range) and outstanding response characteristics (response time of 131.5 ms and recovery time of 86.2 ms). Notably, the hydrogel sensor demonstrates impressive stability during 2000 s of cyclic loading at 100% strain and detects subtle strains as low as 1%, enabling accurate recognition of various human movements. The dual-network PAA/CNC structure, coupled with the synergistic conductivity from the multifunctional fillers, further confers excellent electromagnetic interference shielding performance (37.42 dB at 2 mm thickness). This cellulose-based platform integrates high conductivity, mechanical resilience, and multiscale sensing capabilities, offering a sustainable and scalable solution for next-generation wearable electronics and smart devices.