Animal skins often possess both functions of sensing and actuating to detect external stimulations and change shapes when needed, respectively. Furthermore, many animals, such as jellyfish and leptocephalus (eel larvae) have tissues that are transparent and ultra-stretchable, which are difficult to build in synthetic sensors and actuators. Moreover, all these living skins have self-healing properties, i.e. to restore their critical functions after being damaged. On the contrary, artificial electronic systems are often brittle and non-transparent. As such, biomimetic, skin-like materials have been widely investigated in recent years for potential applications in wearable systems. In the emerging field of flexible and stretchable electronic devices, unexpected mechanical damage is a main cause for device failures. One approach to address this mechanical failure issue is to learn and emulate living things in nature – such as the skin of jellyfish for the self-healing property to extend the service life of electronics.
We report a biomimetic self-healing and ion-conducting hydrogel for applications in sensors and actuators. Compared to the state-of-art, this material has the following features: (1) high transparency with ~85% transmittance within the visible light range; (2) ultra-stretchable without failure under more than 1100% applied strain; (3) excellent self-healing capability with broken pieces fully amended visually in 24 hours; (4) highly adhesive for self-bonding. Applications of healable supercapacitors, Li-ion batteries, strain sensing and mechanical actuator were shown, demonstrating potential for various applications.
In the future, we would like to (1) improve the self-healing capability of the materials or develop other self-healing materials which are suitable for other application situations; (2) realize the application of self-healing materials in other energy harvesting such as thermoelectrics, triboelectrics and so on; (3) integrate with other self-healing materials such as liquid metal composites for self-healable wireless system.
Project ended: 13 Feb 2024