Protein from a small mollusc inspired Michigan Technological University’s Bruce P. Lee to invent a new type of hydrogel actuator.
Because of their soft texture, hydrogels have the potential to interact safely with living tissues and have applications in a number of medical areas, including tissue engineering. Lee, an assistant professor of biomedical engineering, wanted to make a hydrogel that could change its shape. “Hydrogels that can change shape on command could be used to deliver pharmaceuticals”, he said. “We’ve taken a hydrogel and made it into an actuator: something that can change shape or move, maybe by opening the door for a drug and letting it out.”
To make his movable hydrogel, Lee borrowed chemistry from proteins that mussels use to anchor themselves to wet rocks. A hydrogel could be programmed to adopt all manner of shapes by changing the placement of the ions, the composition of the hydrogel and the voltage. You can also remove the ions and reintroduce them in a different pattern, so that the same hydrogel can be reprogrammed to transform into a different shape.
Other scientists have used metal ions to make hydrogel actuators, but no one has used chemistry found in mussel adhesive proteins. Lee hopes to follow up on his initial discovery.
