Non-swelling and temperature tolerant organogels toward multi-environment human motion monitoring

Abstract

Swelling-resistant hydrogel-based flexible electronic devices with temperature tolerance have acquired increasing attention on applications in aquatic environments and extreme climatic conditions. Nevertheless, it remains a great challenge for hydrogel sensors to maintain precisely mechanical perception in aquatic and low-temperature environments because of the swelling and freezing of hydrogels. In this work, the isobornyl acrylate (IBOA) hydrophobic monomer combined with N-hydroxymethylacrylamide (NMA) and 2-hydroxyethyl acrylate (HEA) are introduced into the dimethyl sulfoxide solvent to prepare a multifunctional IBOA-NMA-HEA organogel, which presents the superior flexibility, excellent low-temperature adaptability and long-lasting anti-drying property. Particularly, the resulting organogel also exhibits long-term stability for up to 15 days in various aquatic environments, including pure water, seawater and alkali aqueous solution. Based on these merits, an IBOA-NMA-HEA organogel-based environmentally tolerant strain sensor with rapid response, wide strain range and superior cyclic stability has been fabricated to monitor the human body and marine animal movements in air, low-temperature or underwater conditions. Stable and reliable sensing performances ensure the precise and real-time collection of a series of complex motion signals in various environments. This study provides a facile approach to design anti-swelling, anti-freezing and anti-drying organogels and greatly expand the application of organogel-based flexible electronics.