Tiny soft robot could help cleaning contaminated water

If you like diving or enjoy watching documentaries about aquatic life forms, you know that corals in the Ocean are made up of coral polyps. These soft funny creatures are nourishing the corals and clean the water at the same time. Now scientists at the University of Warwick took inspiration from them and created a tiny artificial aquatic polyp, which is also able to remove contaminants from water.

Artificial polyp is affixed to the ground, but moves around under the influence of external magnetic fields. Image credit: University of Warwick

This tiny robot, measuring just 1 by 1 centimetres is completely wireless. This artificial polyp moves under the influence of a magnetic field while its tentacles are triggered by light. While it could remove contaminants from water, scientists say that it could also be used in medicine – it could be used in diagnostic devices, transporting specific cells for analysis.

Artificial poly doesn’t have an internal integrated mobility system. In fact, just like a real polyp, it doesn’t even more around – it stays in place stuck to the ground. It just dances in its place thanks to a rotating magnetic field under the device. It drives  a rotating motion of the artificial polyp’s stem. This motion creates an attractive flow which can guide suspended targets, which can be oil droplets or other contaminants. UV light then activates the polyp’s tentacles, allowing the robot to grasp the target. It can later be released using a blue light.

Those light-activated robotic tentacles are made of photo-active liquid crystal polymers. They bend towards the light, allowing the artificial polyp to grasp the passing target. UV light makes the robot grab things and the blue light releases them.

An artificial polyp grabs an object:

Scientists used 3D simulations to perfect the shape of those artificial polyps. The shape is very important, because just like real polyps these tiny robots generate flows that attract contaminants towards them. The result is a very efficient device, even if it looks a bit funny. Dr Harkamaljot Kandail, one of the scientists in the study, said: “The next stage for us to overcome before being able to do this is to successfully scale up the technology from laboratory to pilot scale. To do so we need to design an array of polyps which work harmoniously together where one polyp can capture the particle and pass it along for removal.”

For now that tiny polyp is just a proof of concept. It is demonstrating a potential new way to assemble actuators in soft tiny robots. It is wireless and quite efficient. Now let’s see what scientists can make from it.