US – If we let a cube of gelatin on the kitchen counter containing water, water eventually evaporates, leaving it becoming a hardened and shrunken mass, which no longer will be appetizing as before. The same goes for hydrogels. Made mostly of water, these gelatin-like polymer materials are elastic and absorbent until it dries up inevitably.

Now, Xuanhe Zhao team, a professor of mechanical engineering and materials science at the Massachusetts Institute of Technology (MIT), has found a way to prevent hydrogels from dehydrating, with a technique that it could lead to the development of contact lenses making them more durable, elastic microfluidic devices, flexible, bioelectronics and even artificial skin.

Zhao and colleagues devised a method for attaching hydrogels to elastomer (elastic polymers such as rubber and silicone, which are the as hydrogels but at the same time are waterproof). They found that hydrogels coated with a thin elastomer layer provides a barrier that retains the water and keeps the moist, flexible and robust.

The group was inspired to design human skin, which is composed of an outer layer called the epidermis, bonded to a layer (dermis) located underneath. The epidermis acts as a shield, protecting the dermis and network of nerves and capillaries, and the rest of muscles and organs, preventing drying up.

This work was published in the journal Nature Materials.