We all encounter gels in everyday life – soft and sticky substances that you put in your hair, to jelly components in various foodstuffs. Although human skin shares gel type characteristics, it has unique qualities that are very difficult to reproduce. He combines high rigidity with flexibility, and he has remarkable self-healing capacities, often healing completely within 24 hours of the injury.
So far, artificial gels have managed to reproduce this strong stiffness Or The self-healing properties of natural skin, 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 overcomes previous limits, opening the door to applications such as drug administration, wound healing, soft robotics and artificial skin sensors.
In the revolutionary study, the researchers added exceptionally important and ultra-thin clay nanofeuilles to hydrogels, which are generally soft and located. The result is a highly ordered structure with densely tangled polymers between nanofeuilles, not only improving the mechanical properties of hydrogel but also allowing the material to hide.
Research was published in the journal Nature materials March 7.
Heal via “tangle”
The secret of the equipment lies not only in the organized arrangement of nanofeuilles, but also in the polymers which are tangled between them – and a process as simple as cooking. Postdoctoral researcher Chen Liang mixed monomers powder with water that contains nanofeuilles. The mixture was then placed under a UV lamp – similar to that used to adjust the gel nail polish. “The UV radiation of the lamp makes the individual molecules bind so that everything becomes a solid elastic – a gel,” explains Liang.
“The tangle means that the slim polymer layers are starting to twist each other like tiny wool threads, but in random order,” added Hang Zhang, of Aalto University. “When the polymers are fully tangled, they are not distinguished from each other. They are very dynamic and mobile on the molecular level, and when you cut them, they start to intertwine again.
Four hours after cutting it with a knife, the material is already 80 or 90% of guarantee. After 24 hours, it is usually completely repaired. In addition, a thickness hydrogel of one millimeter contains 10,000 layers of nanofeuilles, which makes the material as rigid as human skin, and gives it a comparable degree of stretching and flexibility.
“Rigid, strong and self-careful 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 Zhang.
Befriend nature
“This work is an exciting example of how biological materials inspire us to seek new combinations of properties for synthetic materials. Imagine robots with robust and self-specific skins or synthetic fabrics that are repaired independently, “explains Olli Ikkala, from Aalto University. And even if there can be a way to pass before the real world, the current results represent a pivot jump.” It is the type of fundamental discovery that could renew the rules for the design of materials. “”
The collaboration was led by Dr. Hang Zhang, Professor Olli Ikkala and Professor Josef Breu. The synthetic clay nanofeuilles were designed and manufactured by Professor Josef Breu at the University of Bayreuth in Germany.
(tagstranslate) skin care; Injuries and healing; Beauty products; Psoriasis; Materials science; Nanotechnology; Engineering and construction; Chemistry