Magneto-Responsive, Hyperelastic and Self-Healing Ionoelastomers

Magneto-responsive soft materials with self-healing properties are highly desirable for wearable electronics and soft robotics. However, traditional magnetic materials using metal particles always limit transparency and elasticity despite offering high magnetization. We present a novel Magneto-IoNo-Elastomer (MINE) that overcomes these limitations. MINE combines exceptional magnetization with hyperelasticity and self-healability, while possessing ionic conductivity and transparency. This is achieved through a unique polymer design with urethane groups that effectively confines magnetic anions from magnetic ionic liquids (MILs) <i>via</i> potential hydrogen bonds and metal-coordination bonds. The strong interactions between polymer chains and magnetic anions allow for high MIL loading (up to 80 wt%) while maintaining the material's structural integrity. The versatility of MINE, stemming from multiple reversible bonds, holds great promise for wearable strain sensors, contactless magneto-responsive electronics, and see-through touch panels. The discovery of MINEs will shed new light on applications bridging optics, electricity, magnetism, and stretchability.