3D printable eutectogels with good swelling resistance and electrochemical stability for underwater sensing

In recent years, gel-based ionic conductors have been widely used in wearable flexible sensors due to their superior flexibility and electrical conductivity. However, adapting the gel for use in underwater and extreme conditions, as well as fabricating gel-based flexible devices with intricate structures, presents significant challenges. This study exploits the synergistic effects of hydrophobic/hydrophilic networks and metal coordination to develop an anti-swelling and photocurable eutectogel. The prepolymer composition primarily consists of 2,2,2-trifluoroethyl acrylate (TFEA), hydroxyethyl methacrylate (HEMA), acrylic acid (AA), zirconium oxychloride, and DES solvent. After photocuring, the eutectogel exhibits good mechanical properties, anti-swelling characteristics, environmental stability, electrical conductivity, and sensitivity. Utilizing digital light processing (DLP) 3D printing technology, the eutectogel can be manufactured into a variety of flexible sensors with complex structures, which are capable of recognizing underwater Morse code transmissions for communication applications. In summary, the design of gels presents new opportunities to develop flexible wearable sensor devices suitable for underwater and extreme environments.