On Mar. 7, 2025, a team of researchers from Aalto University and the University of Bayreuth announced that they are the first to develop a hydrogel with a unique structure that overcomes earlier limitations, opening the door to applications such as drug delivery, wound healing, soft robotics sensors and artificial skin. 

In the breakthrough study, the researchers added exceptionally large and ultra-thin specific clay nanosheets to hydrogels, which are typically soft and squishy. The result is a highly ordered structure with densely entangled polymers between nanosheets, not only improving the mechanical properties of the hydrogel but also allowing the material to self-heal. 

The secret of the material lies not only in the organised arrangement of the nanosheets, but also in the polymers that are entangled between them – and a process that’s as simple as baking. Postdoctoral researcher Chen Liang mixed a powder of monomers with water that contains nanosheets. The mixture was then placed under a UV lamp – similar to that used to set gel nail polish. ‘The UV-radiation from the lamp causes the individual molecules to bind together so that everything becomes an elastic solid – a gel,’ Liang explains.

Four hours after cutting it with a knife, the material is already 80 or 90 percent self-healed. After 24 hours, it is typically completely repaired. Furthermore, a one-millimetre-thick hydrogel contains 10,000 layers of nanosheets, which makes the material as stiff as human skin, and gives it a comparable degree of stretch and flexibility.

The research was published in prestigious journal Nature Materials.