All materials react to heat in some way. But this new shape-changing polymer reacts to temperatures as small as the touch of human skin to contract — in the process lifting as much as 1000 times its own weight. The polymer, developed by researchers from the University of Rochester, is a new material that reacts to mechanical forces by becoming increasingly crystalline. As the number of crystals increases, it becomes fixed into a temporarily deformed shape. That's achieved by including a complex mixture of molecular linkers to connect the individual polymer strands in just the right way.
In fact, the researchers have combined them in such a way that heating the polymer to just above 37C causes its to contract back to its original shape. Because it's fairly strong, the process of returning to shape also allows its to lift objects that weigh 1000 times more than its own weight. You can see that happening in this gif, where a heater causes a fine ribbon of polymer to lift a chunk of K'Nex.
Now, the team is working out how it could be used in real-world applications — from body-heat assisted medical devices to, of all things, self-fitting apparel. Right.
Image by University of Rochester
Top image: Multiple-exposure image of the new shape-memory polymer reverting to its original shape.