Hydrogel Hybrid Inspired From Skin Wouldn’t Dry Out Under Any Conditions

As you know, hydrogels are stretchy and strong water-based polymers that are used in a large variety of applications such as smart bandages and contact lenses. The biggest challenge faced with these objects is that these are gel-like substances that dry out after some time, as expected from something that is 90 percent water. Nevertheless, a team of engineers working at MIT recently developed a new kind of hydrogel hybrid that wouldn’t dry out under any conditions.

The human skin is formed of an external epidermis that is closely bonded with rest of the dermis layers beneath it. This epidermis keeps the dermis safe along with its blood vessels, muscles, and everything else that is there. The team working on this project imitated the bond between dermis and epidermis that protects the hydrogels beneath them. But the real question is, which material would actually take up the role of the epidermis? This team finalized that substance to be elastomers that are elastic and rubbery. But these too had their own challenges.

Hyunwoo yuk, an engineer by profession, explains, “Most elastomers are hydrophobic, meaning they do not like water. But hydrogels are a modified version of water. So these materials don’t like each other much and usually, can’t form good adhesion.” Thus, the crux of this research was finding out a suitable and practical method for putting a bond in place between elastomers and hydrogels. Finally, they found an organic substance called benzophenome that can be used for this purpose.

The technology is a pretty direct one. You start the process with a very thin sheet of elastomer. It is then submerged in a benzophenome solution. Once the elastomer is treated, you can wrap it across a hydrogel sheet and then expose this hybrid to ultraviolet rays of light. A strong bond is formed within next 48 hours. The team claims that the bond formed here is a stronger one as compared to epidermis and dermis. The two materials bonded with each other needed some 1000 Joules energy per square meter to separate from each other.