New polymer can retain shape changes, resets with body heat

A team of University of Rochester researchers have developed a new polymer that may play a big part in the medical field in the future. The material is able to maintain a new shape after being stretched or manipulated, something in itself that isn't new, but the incredible part is that it then can be returned to its original shape with just body heat. The researchers say that's only half of their discovery, however, as during shape recovery the polymer is able to release a large amount of stored energy.

"Our shape-memory polymer is like a rubber band that can lock itself into a new shape when stretched. But a simple touch causes it to recoil back to its original shape," said Mitch Anthamatten, a chemical engineering professor and lead researcher on the team. The trigger that causes the return to original shape adjusted to be just below body temperature, so that all it takes is a human touch.

The other unique feature of the polymer is its ability to store as much elastic energy as possible, allowing it to deliver mechanical work during its shape recovery. Because of this, the energy that is released by the material means it can lift something 1,000 times its own weight. As an example, the researchers say shoelace-sized piece of the polymer could lift a liter of soda.

Applying the shape memory polymers to real-world situations would almost always require that the material be pushing or pulling on something. Because of this, they imagine it being used one day for sutures, artificial skin, body-heat assisted medical dispensers, and self-fitting apparel.

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