A wearable ionic hydrogel strain sensor with double cross-linked network for human machine interface

Zijian Wu*, Liying Zhang, Meng Wang, Defeng Zang, Haiyong Long, Ling Weng*, Ning Guo, Junguo Gao*, Yonghong Liu, Ben Bin Xu*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

Abstract

Wearable strain sensor prepared with ionic conductive hydrogel holds great promises in a variety of engineering fields. In this work, we introduce sodium casein (SC) into a dual network hydrogel system made of polyvinyl alcohol (PVA) and polyacrylamide (PAM), to prepare an ionic hydrogel sensor. Compared to the PAM/PVA dual network hydrogel, the introduction of SC plays a significant synergistic role. Such dual network PAM/PVA/SC hydrogels exhibit excellent mechanical properties (a maximum strain of 719%, a maximum stress of 444.3 kPa), low hysteresis and rapid recovery after uni-axial stretching. Since SC drives a large number of free ions, PAM/PVA/SC hydrogels present good conductivity while maintaining high physical stability, to enable an excellent sensitivity in a comparatively large strain range (Gauge factor, GF=2.17 under 400% strain). The unique properties allow the generation of stable and accurate electrical signals transduced from different locations of human body. As such, the PAM/PVA/SC hydrogel has the potential to be used as human machine interface for continuous, real-time physiological monitoring.
Original languageEnglish
JournalAdvanced Composites and Hybrid Materials
Publication statusAccepted/In press - 23 Nov 2024

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