Building Robots that "Fly" on the Ocean Floor

This summer, there was a new underwater presence off the shore of Woods Hole, Massachusetts. Silently navigating the ocean depths, it ascended and descended at regular intervals using its wings to convert this vertical motion to forward motion, essentially “gliding” without the need for a propeller or engine.

 

The “presence” was not a living thing, but rather the creation of a research team that included Miranda Kotidis ’10, currently a senior at MIT in Mechanical Engineering focusing on vehicle design and bio-inspired robotic propulsion.

 

This past summer, Miranda served as a Summer Student Fellow at the prestigious Woods Hole Oceanographic Institution (WHOI). Over the course of the summer, she collaborated with fellow students and researchers to modify the underwater glider. Her specific focus was to design a rechargeable battery pack for it. “It’s complicated to change out the batteries in an underwater vehicle,” she explains. “You also need to rebalance the vehicle, and that can’t be done while you’re out at sea.”

 

Miranda’s summer experience was a perfect complement to her studies, which for the past two years have focused on mechanical engineering and bio-inspired design. In September 2015, she began working in one of MIT’s Ocean Engineering Laboratories, where she is exploring how to recreate the propulsion systems used by animals in the wild. Her first project, a flapping wing for an aerial/underwater vehicle, was inspired by the wing of a puffin, an animal that can both fly in the air and swim in the water.

 

Miranda has since switched to a project that incorporates elements found in the wing of a manta ray. Check out videos of manta rays jumping, Miranda notes, and “you’ll see they can propel themselves more than two body lengths out of the water. There’s a lot we can learn about the manta ray’s musculature and the power it harnesses to move like that. We want to characterize it and recreate it.”

 

One element that made her studies at WHOI so inspiring, she says, was making the direct connection between engineering and research. “One of my friends this summer was actually using the data from our glider to measure trends in the temperature and salinity of ocean currents along the Gulf Stream,” she notes. “It was exciting to have a direct impact on how people were able to do research.”