Liquid Metal-Based Electronic Textiles Coated with Au Nanoparticles as Stretchable Electrode Materials for Healthcare Monitoring

Liquid metals (LMs) have gained great attention due to their fluidic behavior and metallic characteristics, suggesting the LMs to be an ideal electrode material for stretchable electronic textiles (e-textiles) in real-time healthcare systems. Despite advancements in material design techniques enabling LMs to monitor physiologic conditions on the skin, the low biostability of LMs remains challenging for practical use in e-textile. Here, we introduce a mechanically responsive and conductive gold nanoparticle (Au NP) layer as encapsulation on the LM layer to monitor healthcare systems with stretchable benefits. The Au NP-encapsulated LM-based e-textile (AuLM textile) shows high electrical and mechanical stabilities under stretching deformation. We also demonstrate that Au NPs can maintain bonding to the fluidic LM layer when stretched and after stretching. The AuLM textile is equipped with biocompatibility and high electrochemical performance, resulting in multimodal biomedical applications. The electrochemical performance of the AuLM textile allows for sweat component detection and noninvasive, high sensitivity estimation of blood sugar contents. In addition, electrocardiography and electromyography measurements determined that the stretchable platform provides stable monitoring results under motion, and the Au NP encapsulation solves the biostability issue caused by a bare LM environment. This is the first demonstration of preparing stretchable e-textiles using the LM platform with practical and multimodal benefits. The study will open numerous design opportunities for next-generation stretchable bioelectronic applications.