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

Abstract

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.

Electrically Conducting Hydrogels for Health care: Concept, Fabrication Methods, and Applications

“…A recent report by Lim et al . confirmed the theory where silver nanowires were chosen as fillers for alginate hydrogel[ 20 ]. A wearable antenna patch was fabricated using the silver nanowire alginate composite with excellent conductivity, tough structural integrity, and stretchability.…”

Stretchable Supercapacitors: From Materials and Structures to Devices

“…[50,74] Metal materials (e.g., gold, silver, and copper) can be first made into metal nanoparticles or metal nanowires and then doped with polymers to fabricate films as highly conductive collectors. [54,55,65,72] Other methods include preparing soft polymer films or nanofiber webs and then sputtering/spraying metal nanoparticles on the surface to make them conductive. [47,78] Conductive polymers (e.g., PPy, PANI, and polythiophene) can be deposited directly on the polymer surface by electrodeposition to form a conductive layer.…”

Advances in Materials for Soft Stretchable Conductors and Their Behavior under Mechanical Deformation

“…Other groups created hydrogel-based wireless antennas. Lim et al fabricate a wireless antenna with a nanocomposite AgNW/alginate hydrogel supported by a PAAm-hydrogel substrate [ 261 ] whereas Xu et al display high-resolution patterning of liquid metal on a PVA hydrogel for near-field communication (NFC) ( Figure 24 a,b) [ 111 ].…”