Ionotronic Tough Adhesives with Intrinsic Multifunctionality.

Ionotronic hydrogels find wide applications in flexible electronics, wearable/implantable devices, soft robotics, and human-machine interfaces. Their performance and practical translation have been bottlenecked by poor adhesiveness, limited mechanical properties, and the lack of biological functions. The remedies are often associated with complex formulations and sophisticated processing. Here, we report a rational design and facile synthesis of ionotronic tough adhesives (i-TAs), which have excellent mechanical, physical, electrical, and biological properties and promise high scalability and translational potential. They consist of an interpenetrating network with high-density amine groups and highly mobile chains, which enable intrinsic adhesiveness, self-healing, ionic stability, cytocompatibility, and antimicrobial functions. The i-TAs in both pristine and swollen states possess high toughness, stretchability, and strong adhesion to diverse substrates such as tissues and elastomers. The superior mechanical performance is achieved simultaneously with high ionic conductivity and stability in electrolyte solutions. We further demonstrate the use of i-TAs as wearable devices, strain sensors, and sensory sealants. This work is expected to open avenues for new ionotronics with novel functions and stimulate the development and translation of ionotronics.