Color-changing shirt tracks your heath and monitors the environment

Remember Generra Hypercolor tshirts that would change color in response to heat? Tufts University engineers have created a similar fabric integrated with a variety of chemical sensors. For example, your clothing could monitor your health or detect environmental contaminants. The key, says, biomedical engineer Fiorenzo Omenetto, is their special ink is based on silk, material that can "act like a protective 'cocoon' for biological materials" so the various sensing and color-changing compounds can be mixed in and still function. From Scientific American:

The team made the ink by breaking down raw silk fibers into constituent proteins, which the researchers suspended in water. Next they mixed in various reactive molecules and analyzed how the resulting products changed color when exposed to alterations in their environment. When printed on fabric and worn, pH indicators, for example, could convey information about skin health or dehydration; lactate oxidase could measure a wearer's fatigue levels. The changes are visible to the naked eye, but the researchers also used a camera-imaging analysis to continuously monitor the color variations and create a database of values.

"In the case of a T-shirt, the wearer 'paints' the shirt [through] exercise—with colors correlating to the acidity distribution of their sweat," Omenetto says. The ink could also be adapted to track environmental changes in a room, he says, or to respond to bacteria and follow disease progression.