GEN-ERIC News

MIT researchers have created a new structured gel that can rapidly change color in response to a variety of stimuli, including temperature, pressure, salt concentration and humidity. Among other applications, the structured gel could be used as a fast and inexpensive chemical sensor, said Edwin Thomas, MIT’s Morris Cohen Professor of Materials Science and Engineering. One place where such an environmental sensor could be useful is a food processing plant, where the sensor could indicate whether food that must remain dry has been overly exposed to humidity. Thomas is senior author of a paper on the work to be published in the Oct. 21 online edition of Nature Materials. Structured gels are those that feature an internal pattern such as layers. A critical component of the structured gel developed at MIT 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. Objects that reflect different colors depending on which way you look at them already exist, but once those objects are manufactured, their properties can’t change. The MIT team set out to create a material that would change color in response to external stimuli.