Transparent and Skin-Attachable Silver Nanowire Electrodes Embedded on Dissolvable Polyurethane for Highly Conformable Wearable Electronics

Abstract

Conformal contact with skin is a critical requirement for wearable electronics in medical healthcare, artificial electronics, and human-computer interfaces. Tattoo-like electronics exploiting water-dissolvable polymers have been introduced to directly transfer electronics to the skin increasing conformality and adhesion. However, water-dissolvable polymers cannot be anchored on the skin while maintaining electrical properties because water-based sweat can destroy the polymer substrate. In this study, we present a transparent and skin-attachable electrode (TSE) composed of highly conductive silver nanowires and biocompatible polyurethane composite using surface redissolution by ethanol. The TSE can be fabricated into various patterns by a simple fabrication method and firmly mounted on the skin. There was no reddishness or residue on the attached spot after detachment. Additionally, the TSE showed low mechanical modulus of 225 kPa and an optical transmittance of approximate to 70% at 550 nm. Stable and conformal contact with the skin leads to effective body motion sensing and sensitive electrophysiological signal acquisition due to the low electrical interfacial impedance.