Self-Healing Ionogels for Flexible Electronics: Mechanisms, Design, and Device Integration
Ionogels, which integrate the flexibility and ionic conductivity of ionic liquids with the mechanical robustness of polymer networks, have emerged as pivotal materials for flexible electronics. Their tissue-like biomechanical characteristics enable applications in health monitoring, smart wearables, and human-machine interfaces. However, ionogels are susceptible to mechanical damage under large deformations and continuous loading, leading to structural failure and device degradation. Self-healing capability, imparted through dynamic non-covalent bonds (hydrogen bonds, ionic interactions) and reversible covalent bonds, can significantly enhance device reliability, service life, and safety. This review systematically examines the latest progress in self-healing ionogels (SHIGs), covering self-healing mechanisms, design strategies, and preparation methods. Key applications are analyzed, including wearable strain sensors, flexible triboelectric nanogenerators, supercapacitors, flexible displays, and soft robots. The review highlights recent breakthroughs, such as rapid self-healing (within minutes) and superior toughness (fracture energy exceeding 10 kJ m⁻²) in ionically crosslinked polymer ionogels, and record-breaking mechanical properties in room-temperature self-healing ionogels inspired by sea cucumber dermis. Despite these advances, challenges persist in balancing self-healing efficiency with mechanical strength, achieving cost-effective scalability, and ensuring long-term stability under extreme conditions. Perspectives on future development are provided, emphasizing the need for multifunctional integration and standardized testing protocols to accelerate the commercialization of self-healing ionogels in next-generation flexible electronics.