Wearable sensing technology has a broad application prospect in the fields of real-time health monitoring and motion detection. Conductive hydrogel materials are widely studied for wearable sensing because of their good conductivity, biocompatibility and elastic modulus close to human skin. However, it is still a huge challenge to achieve high tensile strength, self-adhesiveness and long-term water retention in the hydrogel system, which limits their application in wearable electronic devices. In addition, traditional manufacturing technologies mainly rely on forming and casting, which greatly limits their application scope and manufacturing scalability. Therefore, the development of a multifunctional 3D printing hydrogel material is of great significance for the development of wearable sensing technology.

In this study, Wang Yifan, assistant professor of Nanyang University of Technology, and others prepared a multifunctional 3D printing hydrogel material by introducing chemical cross-linking network (PAAm/PAAC/PEGDA), physical cross-linking network (PAAm/PAAC/PEGDA/silk fibroin/glycerol/water) and surface microstructure. By introducing negatively charged atoms and lone pair electron polymer chains into the hydrogel, strong adhesion can be formed with the biological substrate because they can form hydrogen bonds with the substrate. By adjusting the content of silk fibroin, the author realized the regulation of the adhesion of hydrogel. By introducing conductive ions into the hydrogel, the conductivity of the hydrogel can be adjusted, so that it has good sensing performance. A strain sensor based on hydrogel was prepared and its sensing performance was tested. The author has prepared an adhesive pressure sensing device with sweat release channel and a 10 channel adhesive strain sensing system for gesture recognition, demonstrating the application potential of hydrogel in the field of wearable sensing.

Source: Sensor Expert Network