Colorfully detecting stressed-out polymer films, gels before they break

Stretchy films and squishy gels help make wearable electronics, soft robotics and biocompatible tissues a reality. But too much force can cause these polymers to break apart without warning. To detect stress before it's too late, researchers reporting in the Journal of the American Chemical Society show they have designed a compound with "wings" that makes these materials change color when they are stretched or crushed.