Adhesive, stretchable and antibacterial hydrogel with external/self-power for flexible sensitive sensor used as human motion detection

Conductive, flexible and stretchable hydrogel sensors have attracted a lot of interest in human-machine interfaces, medical monitoring, and soft robotics. However, there are still have great challenges in the preparation of conductive hydrogels with self-adhesive, self-power and antibacterial properties. In order to meet the requirements of high sensitivity, convenient carrying and anti-allergic, so as to overcome the problems of traditional sensors, such as non-stickiness, absolute dependence on external power supply and skin irritation, the prepared poly(vinylalcohol)/poly(acrylamide-co-[2-(methacryloyloxy) ethyl] dimethyl-(3-sulfo-propyl) ammonium hydroxide) (PVA/P(AM-co-SBMA), PPS) hydrogel was obtained by UV crosslinking and freeze-thaw cycles. The PPS hydrogel has good mechanical properties (the elongation was 700% and the breaking strength was 370 kPa), high adhesion to various substrates, antibacterial properties (similar to 99%) and wide sensory sensitivity. And the self-power sensor can be achieved by using hydrogel as the conductive medium to assemble primary battery with zinc foil and copper foil, the open circuit voltage of this self-powered system can reach 0.86 V. Furthermore, the assembled strain sensor can also convert chemical energy into electrical energy, and transform the resistance changes caused by stretching or compression into voltage signals for output. It can be used as effective wearable power supply for human motion detection. This kind of self-adhesive and antibacterial self-powered strain sensor was expected to play a great role in flexible bioelectronics.