Nanocomposite material gets stronger when stressed

Nanocomposite material gets stronger when stressed: "If someone does a lot of arm curls at the gym, the typical result is that the bones and muscles in their arms will get stronger. Recently, researchers at Houston's Rice University inadvertently created a nanocomposite that behaves in the same way. Although the material doesn't respond to static stress, repeated mechanical stress will cause it to become stiffer."