Scientists have developed a hydrogel that mimics the flexibility, strength, and self-healing properties of human skin. This new material could transform applications in wound healing, soft robotics, and drug delivery.
Hydrogels are common in everyday life, found in hair gels and food products. Yet, replicating the unique qualities of human skin—its toughness, flexibility, and ability to heal—has been a major challenge. Until now, artificial gels could achieve either high stiffness or self-healing but not both.
Researchers from Aalto University and the University of Bayreuth have created a hydrogel with a unique nanosheet structure. They have overcome previous limitations. This achievement paves the way for revolutionary applications.
SELF-HEALING THROUGH MOLECULAR ENTANGLEMENT
The key to this hydrogel’s properties lies in its nanosheets and polymer entanglement. Scientists added ultra-thin clay nanosheets to hydrogels, creating an organized, densely entangled polymer structure. This not only strengthens the gel but also enables rapid self-repair.
Postdoctoral researcher Chen Liang developed the material by mixing monomer powder with water containing nanosheets. The mixture was exposed to UV light, which triggered polymerization, turning it into an elastic gel.
“When fully entangled, the polymer chains twist together like wool yarns,” explained researcher Hang Zhang. “At the molecular level, they are highly dynamic. When cut, they naturally begin to intertwine and repair themselves.”
Within four hours, the material heals up to 90%. After 24 hours, it fully restores itself. A one-millimeter-thick hydrogel contains 10,000 nanosheet layers, giving it stiffness, flexibility, and self-repair abilities comparable to human skin.
POTENTIAL FOR FUTURE INNOVATIONS
“This discovery solves a long-standing challenge in hydrogel research,” said Zhang. “Our method strengthens soft hydrogels, making them suitable for bio-inspired applications.”
Biological materials often inspire new synthetic materials. “Imagine robots with self-healing skins or synthetic tissues that repair themselves,” said Prof. Olli Ikkala from Aalto University.
While real-world applications are still in development, this breakthrough marks a major step forward in material science. “This fundamental discovery could reshape how we design future materials,” added Ikkala.
The study was led by Dr. Hang Zhang, Prof. Olli Ikkala, and Prof. Josef Breu. The synthetic clay nanosheets were designed by Prof. Breu at the University of Bayreuth. The research was published in Nature Materials on March 7.
