Stretchable conductive nanocomposite based on alginate hydrogel and silver nanowires for wearable electronics

Wearable electronic devices are used to perform various electronic functions on the human skin, and their mechanical softness while maintaining high performances is critical. Therefore, there is a need to develop novel materials with outstanding softness and high electrical and ionic conductivity for wearable electronics. Here, we present an intrinsically stretchable and conductive nanocomposite based on alginate hydrogels and silver nanowires (AgNWs). The developed nanocomposite was applied to highly conductive soft electrodes that can be used in various wearable electronic devices. The nanocomposite electrode was prepared by cross-linking alginate molecules in the presence of AgNWs, exhibiting higher electrical, ionic conductivity, higher stretchability, and lower modulus than conventional conducting rubbers. By forming a bilayer structure with the nanocomposite and the ultrasoft hydrogel layer, the mechanical properties of the nanocomposite device could be matched to that of the human skin. We used the nanocomposite electrode for fabricating key device components of wearable electronics, such as a wearable antenna and a skin-mountable supercapacitor. Such demonstrations successfully proved the effectiveness of the proposed nanocomposite as a soft conducting material for wearable electronics.