Preparation of conductive self-healing hydrogels via an interpenetrating polymer network method

Conductive self-healing hydrogels and related soft sensor devices are gaining extensive attention from academia to industry because of their impacts on the lifetime and ergonomic design of artificial skins and soft robotics, as well as health monitoring systems. However, so far the development of such a material has been limited considering performance and availability. In this work, we developed composite hydrogels of acrylamide, polyacrylamide, dialdehyde-functionalized poly(ethylene glycol) and conductive carbon black through an interpenetrating polymer network strategy. After optimizing the composition ratio, the resultant hydrogel exhibited self-healing reversibility mechanically and electrically when cut and self-healed. We used H-1 NMR and FT-IR spectroscopy to determine the self-healing mechanism of the system, thus demonstrating that the cooperative effect of the dynamic covalent and noncovalent interactions contributes to the self-healing capability of the gel. Rheology, scanning electron microscopy and light-emitting diode circuits were carried out to examine its macroscopic and microscopic properties, making it possible to apply in soft and conformable electronics.

Automated summary

This study developed a novel conductive self-healing hydrogel through an interpenetrating polymer network strategy, showing reversible self-healing in both mechanical and electrical properties. The self-healing mechanism was determined using H-1 NMR and FT-IR spectroscopy, demonstrating the cooperative effect of dynamic covalent and noncovalent interactions for its self-healing capability. The hydrogel's macroscopic and microscopic properties were examined through rheology, scanning electron microscopy, and light-emitting diode circuits, showing potential for applications in soft and conformable electronics.