Multifunctional breathable electronic devices for smart wearable healthcare applications

Although multifunctional electronic devices have been widely investigated for wearable healthcare applications, it is still challenging to simultaneously achieve high stretchability, gas permeability, chemical stability, and robust sensitivity without signal interference. Here, we develop a multifunctional breathable electronic device by using porous polystyrene-b-poly(ethylene-r-butylene)-b-polystyrene (pSEBS) films, and two types of gold hollow nanowires (AuHNWs) and Ag@Au core–shell nanowires (Ag@AuNWs) for smart wearable healthcare applications. The porous film enables high breathability (2428.9 ± 9.1 g/m2/d) with a low elastic modulus (0.3 MPa), providing high skin compatibility. AuHNWs and Ag@AuNWs exhibit distinctive electrical properties with high chemical stability (ΔR/R0 ≈ 5 % under 30 % of H2O2) and stretchability (AuHNWs = 80 %, Ag@AuNWs = 100 %). The strain sensor using AuHNWs shows high strain sensitivity (ΔR/R0 = 19.07 at 80 %) with low temperature sensitivity (0.000951 °C−1), whereas the temperature sensor and the on-demand heater using Ag@AuNWs show high temperature sensitivity (0.001457 °C−1) with low strain sensitivity (ΔR/R0 = 0.02 at 80 %). In combination, the stretchable sensors show high strain and temperature sensitivity to monitor body motion and skin temperature without signal interference. Furthermore, the on-demand heating system can be used to control the skin temperature precisely. Taken together, this skin friendly wearable device would be harnessed as a promising platform for futuristic smart wearable healthcare application.