Researchers from Eindhoven University for Technology created a tiny plastic robot made of responsive polymers that moves under the influence of light and magnetism. The team hopes that one day this robot could be used to clean water and transport cells for analysis in diagnostic devices.

In the future this 'wireless aquatic polyp' should be able to attract and capture contaminant particles from the surrounding liquid or pick up and transport cells for analysis in diagnostic devices. Source: Marina Pilz Da CunhaIn the future this 'wireless aquatic polyp' should be able to attract and capture contaminant particles from the surrounding liquid or pick up and transport cells for analysis in diagnostic devices. Source: Marina Pilz Da Cunha

When developing the new robot, the team was inspired by coral polyp. Coral polyp are small and soft with tentacles that make up corals in the ocean. They have the ability to interact with the environment through self-made currents. A stem of living polyps creates movement in the water that attracts food particles so they can grab food with their tentacles.

The new wireless artificial polyp is one centimeter by one centimeter, with a stem that reacts to magnetism and light-steered tentacles. Different light wavelengths create different tentacle reactions. Under UV light, the tentacles grab, and under blue light they release.

The team also created a material that allows the robot to operate underwater. It is a photomechanical polymermaterial that moves under the influence of light. The material can hold deformation after it is activated by light. It immediately returns to its original shape after the stimuli are removed. Once it returns to the original state, the molecules in the material takes on a new state. This allows for different stable shapes to be maintained for a longer period of time.

The position of the tentacles had an influence on the flow of the surrounding fluid, but the robot operates independently from the composition of the liquid it is in. This is unique from current stimuli responsive materials, which are very sensitive to its environment. But the new robot works the same no matter what liquid it is in.

The team’s next step is to create an array of polyps that can work together for biomedical applications.

A paper on this research was published in PNAS magazine.