Bioinspired micro-robots use light to swim
Pictured above are two microrobots swimming in Petri dishes
Inspired by the movement of water striders cruising on the surface of water, a research group led by Professor Hamed Shahsavan have designed smart, soft microrobots whose movements can be controlled by light, offering exciting possibilities in environmental remediation and biomedical applications.
Imagine autonomous robots deployed to clean up microplastics in bodies of water. The research also has potential in biomedical applications. Microrobots could be guided inside the human body to conduct medical procedures.
“We’re moving toward smart swimming robots with more autonomous behaviour, by making them respond to external cues like light, or magnetic fields,” said Shahsavan, a professor in the Department of Chemical Engineering.
Watch the response to light
The research team used the movement strategy of Gerridae insects (water striders). These insects secrete low surface tension chemicals through their bodies to water (high surface tension), creating a differential surface tension that propels them onto water. They then manipulate the water’s surface using the change in the shape of their legs to steer.
The research team replicates the propulsion by the release of low surface tension fuels stored in proteins extracted from suction cups of squid. Then proteins are integrated into swimmers made from photo-responsive materials. When exposed to light, the swimmers' flexible legs bend upward or downward, allowing them to move on the surface of the water.
This research builds upon previous work and was conducted using two-dimensional sheets. The next step for the research group is to create 3D robots capable of navigating both at the surface and underwater environments. They are also exploring other propulsion methods, such as magnetic fields, to expand the robots' capabilities.
This research was led by graduate students, Chuqi Huang of the University of Michigan Ann-Arbor and Natalie Pinchin of the University of Waterloo, supervised by Professor Abdon Pena-Francesch and Prof. Hamed Shahsavan, respectively.
The study is now published in the Journal of Advanced Functional Materials.