Hydrogels That Heal Like Human Skin

Now, a research team from Aalto University and the University of Bayreuth has achieved a major breakthrough: a hydrogel with a highly ordered nanostructure, capable of self-repairing while maintaining mechanical strength and flexibility. Their study, published in Nature Materials demonstrates a material that could revolutionize wound healing, artificial skin, and soft robotic sensors. 

The innovation lies in the addition of ultra-thin clay nanosheets to the hydrogel. These nanosheets form a densely entangled polymer network, strengthening the material while enabling rapid self-healing. 

• The gel is created by mixing monomers with nanosheet-infused water and exposing the solution to UV radiation, similar to the process used for gel nail polish. 

• The polymers intertwine randomly, much like fibers in wool yarn, making them indistinguishable at the molecular level. 

• When cut, these polymers naturally reconnect, allowing the material to heal itself. 

“Stiff, strong, and self-healing hydrogels have long been a challenge. We have discovered a mechanism to strengthen conventionally soft hydrogels. This could revolutionize the development of new materials with bio-inspired properties,” explains Hang Zhang, lead researcher at Aalto University. 

The hydrogel demonstrates remarkable self-repairing capabilities: 

• 80-90 percent healing occurs within four hours after being cut. 

• After 24 hours, the material is fully restored. 

• A one-millimeter-thick hydrogel contains 10,000 nanosheet layers, giving it strength and flexibility similar to human skin. 

“This work is an exciting example of how biological materials inspire us to look for new combinations of properties for synthetic materials. Imagine robots with robust, self-healing skins or synthetic tissues that autonomously repair,” says Olli Ikkala, a professor at Aalto University. 

While real-world applications may still be a few steps away, this discovery reshapes material science. Potential future applications include: 

• Self-healing artificial skin for prosthetics and wearable sensors 

• Soft robotics with damage-resistant exteriors 

• Next-generation wound dressings that accelerate tissue regeneration 

• Drug delivery systems that react dynamically to environmental conditions 

“This is the kind of fundamental discovery that could renew the rules of material design,” Ikkala adds. The research was led by Dr. Hang Zhang, Prof. Olli Ikkala, and Prof. Josef Breu, with the synthetic clay nanosheets developed at the University of Bayreuth. 

MEDICA-tradefair.com; Source: Aalto University