A class of self-healing supramolecular gels and their hybrids with conductive polymer gels for energy and electronic applications
Physical Sciences : Materials and Compounds
Available for licensing
- Guihua Yu, Ph.D. , Mechanical Engineering
- Ye Shi, M.S. , Texas Materials Institute
- Xiaopeng Li , Texas State University
Self-healing materials with conductive properties have attracted growing interest in both academia and industry due to their potential applications in a broad range of technologies, such as self-healing electronics, medical devices, artificial skins, and soft robotics. For practical applications, these materials should demonstrate good conductivity and repeatable mechanical and electrical self-healing properties at room temperature, as well as decent mechanical strength and flexibility, to meet the requirements for fabrication of flexible devices.
Great efforts have been dedicated to developing conductive self-healing materials. Recently, micro-capsules containing liquid precursor healing agents for structural healing were developed. In these systems, the local healing agent is depleted after capsule rupture. One group demonstrated an alternative approach by combining a supra-molecular organic polymer and nickel micro-particles, resulting in a composite with mechanical and electrical self-healing properties at ambient conditions; however, a large number of inorganic particles are needed for the preparation of composite. Most recently, a conductive and self-healing hydrogel by polymerization of pyrrole within agarose matrix was synthesized. The self-healing behavior of the resultant composite, however, can only be excited under external thermal or optical stimuli. Therefore, the development of self-healing, highly conductive, mechanically strong, and lightweight materials remains a critical challenge.
Researchers at The University of Texas at Austin have invented a hybrid gel material synthesized by introducing self-assembled supramolecular gel into conductive polymer gel template. The supramolecular gel consists of organic ligands and metal ions while conductive polymer gels are nanostructured conductive polymers. This hybrid gel shows features of high conductivity, appealing mechanical and electrical self-healing property without any external stimuli and enhanced mechanical strength and flexibility. The "host-guest" synthetic method could be applied for other multi-functional polymeric hybrid materials. Self-healing devices, flexible and printable electronics, artificial skins, durable medical devices, and energy devices could be developed based on this hybrid gel system.
To demonstrate its potential for practical applications, thin films of the hybrid gel were fabricated on flexible substrates to test their self-healing electrical properties. It was shown that the conductivity of the hybrid gel developed is among the highest values of conductive gels, and most importantly, the conductivity can be maintained after extensive bending and stretching tests due to their good self-healing property. Lastly, electrical self-healing properties were demonstrated with a simple electrical circuit made of the hybrid gel; after being cut, it only takes about a minute for the circuit to self-heal and recover its original conductivity.
- Room temperature self-healing without external stimuli
- Scalable and cost-effective fabrication method
- Facile and general method to synthesize a new class of polymeric materials
- High conductivity
- Decent mechanical strength and flexibility
- Room-temperature self-healing behavior without any external stimuli
Self-healing devices, flexible & printable electronics, wearable technologies, artificial skins, durable medical devices, robotics, and energy devices.
- 1 U.S. patent application filed