We all find gels in daily life, from soft and sticky substances that you put in your hair, to gelatin components in several foods. While human skin shares gel characteristics, it has unique qualities that are very difficult to replicate. It combines high rigidity with flexibility, and has notable self -care capabilities, often completely cured within 24 hours after the lesion.
Until now, artificial gels have managed to replicate this high rigidity either Natural skin autocuration properties, but not both. Now, a team of researchers from the University of Aalto and the University of Bayreuth are the first to develop a hydrogel with a unique structure that exceeds the previous limitations, opening the door to applications such as medication administration, wound healing, soft robotics sensors and artificial skin.
In the innovative study, the researchers added exceptionally large and ultrafine clay nanohas to hydrogels, which are typically soft and soft. The result is a highly ordered structure with densely tangled polymers among the nanohas, not only improves the mechanical properties of the hydrogel, but also allows the material to be self -demand.
The research was published in the magazine Nature materials On March 7.
Healing through ‘Entanglement’
The secret of the material is not only in the organized disposition of the nanohjas, but also in the polymers that are entangled between them, and a process that is as simple as baking. Postdoctoral researcher Chen Liang mixed a monomer dust with water containing nanohas. Then, the mixture was placed under a UV lamp, similar to that used to establish gel nail polish. “The UV radiation of the lamp causes individual molecules to join so that everything becomes an elastic solid, a gel,” explains Liang.
“Tangling means that the thin polymer layers begin to twist, such as small wool threads, but in a random order,” adds Hang Zhang, from the University of Aalto. ‘When polymers are completely tangled, they are indistinguishable from each other. They are very dynamic and mobile at the molecular level, and when you cut them, they begin to intertwine again.
Four hours after cutting it with a knife, the material is already at 80 or 90 percent autured. After 24 hours, it is usually completely repaired. In addition, a hydrogel of a millimeter thick contains 10,000 layers of nanohjas, which makes the material as rigid as human skin, and gives it a comparable degree of stretching and flexibility.
‘Rigid, strong and self -colurars 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 bioinseal properties, “says Zhang.
Gaining inspiration of nature
‘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 solid skins and self -care or synthetic tissues that repair freelancer, “says Olli Ikkala, from the University of Aalto. And although there may be some way to go before the application of the real world, the current results represent a fundamental jump.” It is the fundamental type of discovery that could renew the rules of material design. “
The collaboration was directed by Dr. Hang Zhang, Prof. Olli Ikkala and Prof. Josef Breu. The synthetic clay nanohas were designed and manufactured by Professor Josef Breu at the University of Bayreuth in Germany.