"We stumbled into these interesting materials," he says, when NCSU researcher Meixiang Wang was experimenting with ionogels, materials made of a polymer swollen with an ionic liquid that conducts electricity. Wang was trying to make stretchable, wearable devices that might be used in a pressure sensor, other medical devices or robotics. Altering the composition, Wang produced a gel that looked at first like a "mundane piece of transparent, flexible plastic" before testing showed it was very hard ?" but not brittle like other common plastics.