When stress is applied to the above polymers, they change colors - in this case from orange to green, or from green to blue.

This chameleon-like property could make these materials useful in packaging, as a way to identify tampering.

Researchers at Case Western Reserve University have added small amounts of fluorescent dyes to ordinary polymers.  The blends emit light, but the color changes when they are stretched or twisted.

Besides the potential application in inexpensive anti-tampering sensors, this technology could be used for early detection of machine failures.

The researchers have already developed a "smart" fishing line, which alerts a fisherman when there has been too much strain on his or her line.

-- LiveScience Staff

Credit: Case Western Reserve University