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A novel device for capturing delicate, undiscovered sea creatures

It’s a well-known fact that we currently know less about the ocean floor than we do about the surface of the moon. Our oceans are the largest and least explored environments on the planet, and scientists estimate they may contain up to a million species that are yet to be discovered. Still, deep-ocean dives in specially designed submersibles frequently turn up new species. Many of these organisms are soft-bodied – similar to jellyfish, squid, and octopuses – which makes them difficult to capture for study without harming them.

Luckily, a new device has just been developed by researchers at Harvard University’s Wyss Institute, John A. Paulson School of Engineering and Applied Sciences (SEAS), and Radcliffe Institute for Advanced Study. This device can capture soft-bodied species for study inside a folding polyhedral enclosure, before letting them go unharmed. The research is reported in Science Robotics.

The device was designed and built by Zhi Ern Teoh, Ph.D., and consists of five 3D-printed polymer “petals” attached to rotating joints that are linked together to create a scaffold. A motor applies torque to the point where the petals meet, resulting in the entire structure rotating about the joints and folding into a hollow dodecahedron – which is a twelve-sided 3D shape, almost like a rounded box. This device has been named the Rotary Actuated Dodecahedron (RAD).

The RAD sampler was tested at the Mystic Aquarium in Mystic, CT, where it successfully collected and released moon jellyfish underwater. It was then modified to withstand open ocean conditions, and mounted on an underwater remotely-operated vehicle (ROV) provided by the Monterey Bay Aquarium Research Institute in Monterey, CA. The device was tested in the field at depths of 500-700 meters, using the ROV’s manipulator arm and a human-controlled joystick to operate the RAD. In the field, the team was able to capture soft organisms like squid and jellyfish in their natural habitats, and then release them unharmed.

The RAD sampler design is perfect for the difficult environment of the deep ocean because its controls are very simple, so there are fewer elements that can break. It’s also modular, so if something does break, we can simply replace that part and send the sampler back down into the water,” says Teoh. “This folding design is also well-suited to be used in space, which is similar to the deep ocean in that it’s a low-gravity, inhospitable environment that makes operating any device challenging.”

Teoh is currently working on a more rugged version of the RAD to be used in heavy-duty underwater tasks – such as marine geology. Robert Wood, Ph.D., a Founding Core Faculty member of the Wyss Institute, explains how the benefits of this device go beyond its practical use:Our group’s collaboration with the marine biology community has opened the door for the fields of soft robotics and origami-inspired engineering to apply those technologies to solve problems in an entirely different discipline, and we are excited to see the ways in which this synergy creates novel solutions.”

By Connor Ertz, Staff Writer

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