Hydrogels are gelatin-like polymer materials. The material can be stretched and is highly absorbent. A hydrogel is a so-called “smart material” that can change its structure in response to salt concentration, pH and temperature. Hydrogels also very flexible and many types exhibit the phenomenon of thixotropy (here they become fluid when agitated and re-solidify when rested). The basis of the materials is polymers.
To prevent hydrogels from running out, Massachusetts Institute of Technology (MIT) scientists have developed a method that strongly links hydrogels to elastomers (such as silicone), which makes them impervious to water. The elastomer functions as a type of water-trapping barrier. This keeps the hydrogel moist and flexible, and maintaining its original flexibility. With the new research the elastomer benzophenone was used to coat a hydrogel.
Hydrogels are highly absorbent (they can contain over 99.9 percent water), formed from natural or synthetic polymers. The elastomer enhances this absorbent quality. While there could be alternative means of preventing moisture loss, the reason for coating the hydrogels is so they remain compatible with biological applications.
Further details are shown in this video:
Applications of hydrogels include contact lenses, stretchy microfluidic devices, flexible bioelectronics, and artificial skin. The lead researcher, Xuanhe Zhao, the Robert N. Noyce Career Development Associate Professor in MIT’s Department of Mechanical Engineering, is most interested in using the new development for the creation of artificial skin.
Interviewed by Controlled Environments magazine, Professor Zhao said: “We hope this work will pave the way to synthetic skin, or even robots with very soft, flexible skin with biological functions.”
For this, the research group are a developing a technique to create tiny channels into the hybrid material that are similar to blood vessels. In addition, they are also working on embedding complex ionic circuits into the hydrogel material in order to mimic nerve networks.
The new development is published in the journal Nature Communications. The research paper is titled “Skin-inspired hydrogel–elastomer hybrids with robust interfaces and functional microstructures.”
In related news, medical scientists are working on photothermal therapy using hydrogels to deliver anti-cancer medications, targeted at cancerous tumors. A range of hydrogel innovations are currently trending on Twitter.
