A robust and adhesive anti-swelling hydrophobic ionogel with prolonged stability for strain and temperature sensors

Abstract

With the growing attention brought by wearable electronic devices, flexible sensors, as a fundamental component, are emerging as the focal point. However, achieving long-term stability and precise sensing underwater remain two significant challenges that urgently need to be addressed for sensors. In this study, we designed a hydrophobic ionogel (MCS) with good stretchability (720%), excellent wet adhesion, prolonged stability and anti-swelling capability. These remarkable advantages make ionogels stand out as strain sensors. The ionogels exhibit extraordinary signal sensing abilities. In specific, they can capture subtle physiological activities of the human body with precision and sensitivity both in air or underwater. Besides, the satisfactory thermosensitivity (-2.02%/ºC), high resolution (0.1 ºC) and fast response (14 s) ensure that the ionogel becomes a qualified temperature sensor. By integrating with a wireless Bluetooth transmission system, the real-time body temperature can be monitored by a smart cellphone. This work demonstrates great potential of MCS ionogel in marine exploitation and wearable health monitoring.