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

Abstract

With the growing attention given to 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 these sensors. By employing a fully hydrophobic structure, this work achieves a significant breakthrough in underwater applications. The hydrophobic design imparts the ionogel with exceptional water resistance, strong wet adhesion, and remarkable stability in underwater environments. These remarkable advantages make ionogels stand out as strain sensors. The ionogels exhibit extraordinary signal sensing abilities. Specifically, 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% °C⁻¹), high resolution (0.1 °C) 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 using a smart cellphone. This work demonstrates the great potential of ionogels in marine exploitation and wearable health monitoring.