Inspired by earthworms, which use peristaltic locomotion to wriggle, an engineering student at the University of Cincinnati's College of Engineering and Applied Science used a worm’s contracting and expanding motion to provide a way for gels to freely swim in liquids.
While peristaltic motion has previously been used by the student’s research team as a mechanism for gels to move in frictional environments, such as on solid ground or inside a tube, now soft materials can move freely without requiring outside friction, by using shrinking and swelling to move the center of gravity of an object in water. He says that this vastly expands the potential applications of soft materials and even soft robot locomotion.
Using a hand-held laser, the team was able to selectively and quickly shrink the hydrogel in desired areas. Then, by inducing a shrinking/swelling cycle down the length of a hydrogel, they were able to successfully mimic peristaltic, or earthworm-inspired, locomotion in water.
Since hydrogels can be equipped to detect bacteria, carry cargo, and deliver medicine, this new method of mobility expands the hydrogel’s use as an environmental and biotechnological tool by allowing them to explore new areas such as cavities within the human body.
