Super-Stretchable, Elastic and Recoverable Ionic Conductive Hydrogel for Wireless Wearable Stretchable Sensor

Stretchable ionic conductive hydrogel based sensor has been considered as one of the best candidates for real-time monitoring of human body motion as a wearable health-care detection electronic device, due to its outstanding flexibility and high sensitivity. In the detection of body motion, the ionic conductive hydrogel is sensitive to its deformation. However, the fatigue of currently reported hydrogels makes them difficult to recover to their initial shape after numbers of repeatedly stretching cycles, leading to their response insensitivity and service life degradation. In this work, a super-stretchable and recoverable ionic conductive hydrogel (double network polymer hydrogel (SA-Zn): ZnSO4/sodium alginate/poly acrylic-acrylamide) was designed as a stretchable sensor for human body motion detection. The SA-Zn hydrogel exhibits outstanding stretchability (up to 4000% tensile strain) and excellent shape self-recovery ability (20 mins recovery time). After self-recovery for 50 cycles, the hydrogel still can keep good flexibility, stable self-recovery ability and high conductivity. Importantly, when combined with WiFi transmitter, the assembled wireless wearable stretchable sensor (SA-Zn-W) can transform human body motion into visual electrical signal, revealing excellent sensitivity, fast response, effective identification and stable electromechanical repeatability. The superior performances offer the SA-Zn-W a great potential for detecting human body motion effectively and remotely.