Coaxially spinning spiral coils into concentric microtubes to synchronize motion and temperature sensing for stretchable and wearable device

Abstract

Wearable electronical sensors with the combination of multi-mode sensing, stretchability and stability have long been in pursuit for various applications, such as the strain and temperature sensing for health assessment and disease diagnosis. To design endurable dual-mode sensor without signal interference, in this study, a coaxial wet spinning process were suggested to spin helical fibers into concentric double-layer microtubes to synchronize motion and temperature sensing with negligible signal interference. The inner helical fiber showed a high temperature-dependent ionic conductivity for the sensitivity of 5.76 % °C−1 and detection limit of 0.1 °C. Its helical geometry ensured large stretchability and minimal strain-induced interference. The outer coating shell could serve as the strain sensor with a high gauge factor of 11.36–1512 (up to 300 % strain) and response time of 120 ms. When filling the microtubes with polydimethylsiloxane, the multi-mode sensos could stay stable sensing abilities up to 104 stretching-release cycles. Thus, this study not only offers a coaxial spinning approach for production of stretchable multicomponent fibers, but also shows an unprecedented alternative of dual-mode sensor for healthcare, rehabilitation, and sleep monitoring.