Mechanically Robust, Antifatigue, and Temperature-Tolerant Nanocomposite Ionogels Enabled by Hydrogen Bonding as Wearable Sensors

Abstract

Flexible wearable sensors originating from ionogels have found extensive and significant applications in electronic skins, body-health monitoring, and personal healthcare diagnosis. Developing an ionogel-based sensor with robust mechanics and durable sensing in a wide service temperature range remains challenging. Herein, a high-performance wearable sensor with temperature-tolerant mechanics and durable sensing was constructed by virtue of hydrogen bonding between a poly(vinyl alcohol) (PVA)-incorporated nanocomposite interpenetrating network and an ionic liquid, i.e., 1-butyl-3-methylimidazolium iodide ([C4mim][I]). Through modulation of hydrogen bonding and thus good compatibility between [C4mim][I] and the network, the ionogels exhibited superior mechanics, excellent antifatigue, and durable sensing in a wide working temperature range. The ionogel-based wearable sensor exhibited stable and repeatable sensitivity toward various human motions including finger bending, elbow joint bending, and swallowing. More importantly, the pressure sensing can be completely preserved in a service temperature range of −20 to 80 °C. This work provided a feasible method to construct a mechanically strong, temperature-durable ionogel-based multimode sensor, which would find versatile applications as electronic skins, human-motion detection, and intelligent devices.