Artificial aquatic polyp could help clean up oceans

Coral polyps are small, soft creatures with a stem and tentacles that nourish corals and aid the coral's survival by generating self-made currents through motion of their soft bodies.

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Now, scientists from WMG at the University of Warwick, led by Eindhoven University of Technology in the Netherlands, have developed a 1cm by 1cm wireless artificial aquatic polyp that, apart from cleaning, could be used in medical diagnostic devices by picking up and transporting specific cells for analysis. Their findings are published in PNAS.

In their paper the researchers demonstrate how their artificial aquatic polyp moves under the influence of a magnetic field, while the tentacles are triggered by light. A rotating magnetic field under the device drives a rotating motion of the artificial polyp's stem. This motion results in the generation of an attractive flow which can guide suspended targets, such as oil droplets, towards the artificial polyp.

Once the targets are within reach, UV light can activate the polyp's tentacles, composed of photoactive liquid crystal polymers, which then bend towards the light enclosing the passing target in the polyp's grasp. Target release is then possible through illumination with blue light.

Dr Harkamaljot Kandail, from WMG, University of Warwick was responsible for creating 3D simulations of the artificial aquatic polyps that were used to optimise the shape of the tentacles so that the floating particles could be captured quickly and efficiently.

In a statement, Dr Kandail, said: "Corals are such a valuable ecosystem in our oceans, I hope that the artificial aquatic polyps can be further developed to collect contaminant particles in real applications. 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."

"The artificial aquatic polyp serves as a proof of concept to demonstrate the potential of actuator assemblies and serves as an inspiration for future devices,” added Marina Pilz Da Cunha, Eindhoven University of Technology. “It exemplifies how motion of different stimuli-responsive polymers can be harnessed to perform wirelessly controlled tasks in an aquatic environment."