70. [Chemical Engineering Journal] Robust and flexible strain sensors based on dual physically cross-linked double network hydrogels for monitoring human-motion
writer：Shan Xia, Shixin Song, Guanghui Gao
keywords：Wearable strain sensors Dual physically cross-linked Double network hydrogels Tough Self-recovery
source：期刊
Issue time：2018年
Soft, stretchable, and elastic hydrogels have recently attracted immense interest due to their potential applications
in wearable strain sensors. However, most of hydrogel-based sensors exhibit poor mechanical properties.
Here, a robust, flexible and strain-sensitive conductive wearable sensor is prepared based on dual physically
cross-linked double network hydrogels consisting of core-shell hybrid nanoparticles cross-linked polyacrylamide
as first network and Ca2+ cross-linked alginate as second network. Dynamic physical cross-linking as sacrifice
bonds can effectively dissipate energy and reconstruct the network structure, endowing hydrogels with high
strength, toughness, stretchability and excellent self-recovery properties. Moreover, the hydrogels exhibit outstanding
strain sensitive behavior with repeatable, stable, and precise changes in resistance signals. Based on the
excellent strain sensitivity, the hydrogel can be assembled as a wearable strain sensor to monitor joint motions
such as finger, wrist, elbow, neck, and knee joints, and even the slight motions including breathing and speaking.
Thus, the tough, anti-fatigue, self-recovery and conductive hydrogels have promising potential as soft, highperformance
and flexible wearable strain sensor for soft robots, biomimetic prostheses, human activity monitoring
and health-monitoring systems.