Textile-Integrated Liquid Metal Electrodes for Electrophysiological Monitoring

Next generation textile-based wearable sensing systems will require flexibility and strength to maintain capabilities over a wide range of deformations. However, current material sets used for textile-based skin contacting electrodes lack these key properties, which hinder applications such as electrophysiological sensing. In this work, a facile spray coating approach to integrate liquid metal nanoparticle systems into textile form factors for conformal, flexible, and robust electrodes is presented. The liquid metal system employs functionalized liquid metal nanoparticles that provide a simple peel-off to activate means of imparting conductivity. The spray coating approach combined with the functionalized liquid metal system enables the creation of long-term reusable textile-integrated liquid metal electrodes (TILEs). Although the TILEs are dry electrodes by nature, they show equal skin-electrode impedances and sensing capabilities with improved wearability compared to commercial wet electrodes. Biocompatibility of TILEs in an in vivo skin environment is demonstrated, while providing improved sensing performance compared to previously reported textile-based dry electrodes. The spray on dry-behave like wet characteristics of TILEs opens opportunities for textile-based wearable health monitoring, haptics, and augmented/virtual reality applications that require the use of flexible and conformable dry electrodes.

Automated summary

This study presents a method of spray coating liquid metal nanoparticle systems onto textiles to create flexible and robust electrodes. The resulting electrodes, known as TILEs, exhibit comparable sensing capabilities and skin-electrode impedance to commercial wet electrodes, while also providing improved wearability. The biocompatibility of TILEs in a skin environment is demonstrated, and they outperform previously reported textile-based dry electrodes in terms of sensing performance.