Synthesis of UV-Filtering, Self-Healing, and Self-Adhesion Multifunctional Ionogel for Multimodal Sensation Ionic Skins by Electron Beam Irradiation

As an ion-conductive material, multifunctional ionogels are crucial for the development of i-skin materials. However, current designs face significant challenges in simultaneously achieving mechanical properties, along with self-healing capabilities, multimodal sensing, and high sensory precision. In this work, we propose a strategy for the in situ electron beam irradiation-induced copolymerization of highly soluble acrylic acid (AA) and poor-solubility 4-allyloxy-2-hydroxybenzophenone (AHBP) to prepare phase-separated ionogels. AHBP not only enables tunable transparency by adjusting the degree of phase separation but also improves the mechanical properties of the ionogel by modulating the soft/hard domains caused by the solvent-rich and polymer-rich phases. Additionally, AHBP efficiently absorbs UV light through conformational changes. Combined with its excellent conductivity, high thermal stability, and outstanding self-healing and self-adhesive properties, the ionogel-based i-skin demonstrates multimodal sensing capabilities for strain, temperature, and pressure, showing great potential for applications in wearable strain sensors and multisignal sensing arrays.