Facile Preparation of Polymerizable Deep Eutectic Solvents Under Mild Conditions for Multisensory Ionic Skins

Polymerizable deep eutectic solvents (PDESs) have emerged as promising building blocks for next-generation eutectic gels, offering new opportunities for the development of advanced electronic devices. Traditional PDES fabrication typically involves heating and extended processing time. In this study, a facile method where a solid-solid mixture of lithium bis(trifluoromethane) sulfonimide (LiTFSI) and acrylamide (AAm) rapidly forms a PDES at room temperature, significantly simplifying the ionogel preparation is presented. By combining this PDES with another system, comprising 3-[dimethyl-[2-(2-methylprop-2-enoyloxy)ethyl]azaniumyl]propane-1-sulfonate (SBMA) and ethylene glycol (EG), an eutectic gel is successfully fabricated with exceptional mechanical and conductive properties. This gel exhibits a fracture stress of 0.8 MPa, fracture energy of 3.7 kJ m^-2, adhesion strength of 60 kPa, transmittance over 90%, high conductivity (0.113 S m^-1), and an outstanding temperature tolerance ranged from -50 to 50 °C. Notably, the absence of chemical crosslinkers and the presence of reversible interactions such as hydrogen bonding and ion-dipole electrostatic forces impart excellent self-healing capabilities. These combined features position the gel a promising candidate for multisensory ionic skins, capable of detecting pressure, temperature, humidity, and sweat. This work pioneers the rapid, mild-condition synthesis of PDESs, paving the way for new techniques in ionic skin development.