Studying aliens of the deep

Studying aliens of the deep

By Lindsay Brownell

The open ocean is the largest and least explored environment on Earth, estimated to hold up to a million species that have yet to be described. However, many of those organisms are soft-bodied – like jellyfish, squid, and octopuses – and are difficult to capture for study with existing underwater tools, which all too frequently damage or destroy them. Now, a new device 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 safely traps delicate sea creatures inside a folding polyhedral enclosure and lets them go without harm using a novel, origami-inspired design. The research is reported in Science Robotics.

The rotary actuated dodecahedron (RAD) sampler has five origami-inspired “petals” arranged around a central point that fold up to safely capture marine organisms, like this jellyfish. Credit: Wyss Institute at Harvard University

“We approach these animals as if they are works of art: would we cut pieces out of the Mona Lisa to study it? No – we’d use the most innovative tools available. These deep-sea organisms, some being thousands of years old, deserve to be treated with a similar gentleness when we’re interacting with them,” said collaborating author David Gruber, Ph.D., who is a 2017-2018 Radcliffe Fellow, National Geographic Explorer, and Professor of Biology and Environmental Science at Baruch College, CUNY.

The idea to apply folding properties to underwater sample collection began in 2014 when first author Zhi Ern Teoh, Ph.D., took a class from Chuck Hoberman, M.S., a Wyss Associate Faculty Member and Pierce Anderson Lecturer in Design Engineering at the Harvard Graduate School of Design, about creating folding mechanisms through computational means. “I was building microrobots by hand in graduate school, which was very painstaking and tedious work, and I wondered if there was a way to fold a flat surface into a three-dimensional shape using a motor instead,” said Teoh, a former Postdoctoral Fellow at the Wyss Institute in the lab of Robert Wood, Ph.D.; he is now an engineer at Cooper Perkins.

A fellow member of the Wood lab at the time, Brennan Phillips, Ph.D. – now Assistant Professor of Ocean Engineering at the University of Rhode Island – saw Teoh’s designs and suggested he adapt it to capture sea creatures, which are notoriously difficult to grab with existing underwater equipment that is largely designed for the rough work of ocean mining and construction.

The device that Teoh built consists of five identical 3D-printed polymer “petals” attached to a series of rotating joints that are linked together to form a scaffold. When a single motor applies a torque to the point where the petals meet, it causes the entire structure to rotate about its joints and fold up into a hollow dodecahedron (like a twelve-sided, almost-round box), earning it the name of Rotary Actuated Dodecahedron (RAD). The folding is entirely directed by the design of the joints and the shape of the petals themselves; no other input is required.