Scientists create gel that changes color

CAMBRIDGE, Mass., Oct. 22 (UPI) -- U.S. scientists have created a structured gel that rapidly changes color in response to a variety of stimuli, including temperature, pressure and humidity.

Structured gels are those that feature an internal pattern such as layers. A critical component of the structured gel developed at the Massachusetts Institute of Technology is a material that expands or contracts when exposed to certain stimuli. Those changes in the thickness of the gel cause it to change color, through the entire range of the visible spectrum of light.

MIT researchers said their new gel, among many applications, could serve as a fast and inexpensive chemical sensor. Professor Edwin Thomas, senior author of the research, said the gel might also be useful at a food processing plant, where it could indicate whether food that must remain dry had been overly exposed to humidity.

The team is also working on a gel that changes color in response to applied voltages.

The research that included former MIT postdoctoral associate Youngjong Kang and graduate students Joseph Walish and Taras Gorishnyy, appears in the online edition of the journal Nature Materials.