Student designs sensor for ocean microplastic research

More than 250 metric tons of microplastic are estimated to be floating in the world’s oceans. And the cost to take a research vessel out to study those particles and their dispersion patterns can be astronomical.

To solve the high-cost issue, without sacrificing on data collection, a Northeastern student created a sensor to gather and categorize microplastics.

Ethan Edson, S’15, presented his “Mantaray” prototype sensor at RISE:2015 this past April and earned the undergraduate award in the Engineering and Technology category. He graduated in May with his bachelor’s degree in environmental science.


A break down of the “Mantaray’s” different parts. Courtesy of Edson’s RISE:2015 poster

As a first deployment this summer, Edson said he hopes to use the sensor to collect microplastics in Boston Harbor.

His inspiration for the project came while participating in the SEA Semester program in Woods Hole, Massachusetts, two years ago, when Edson was studying bacteria growth on microplastics that he collected by dragging a net behind a boat. He saw an opportunity to streamline the process and eliminate the need for manpower or a research vessel.

“It just seemed like there could be a better way to have a sensor that could collect microplastics,” Edson said.

Microplastics are defined as particles that are smaller than five millimeters. Edson explained on his RISE poster that microplastics are becoming invasive in marine ecosystems and are harmful to marine species. Identifying global dispersal patterns is difficult because of diverse concentrations across the world’s oceans.

The “Mantaray” features a flow-through system to pump sea surface water through itself. An optical sensor identifies microplastics within the water and stores them in one of 28 filters. The device would also include a GPS system to track where in the ocean the microplastics are collected, as well as a water temperature sensor and a salinity sensor.

RISE:2015 Awards Ceremony

Edson, center, is flanked by President Aoun, right, and Provost and Vice President for Academic Affairs Stephen Director, left, at the RISE:2015 award ceremony in April. Photo by Matthew Modoono/Northeastern University

Following RISE, Edson continued working on the apparatus that would hold the sensor when it’s in water. One of the key components of the apparatus will be a solar panel on top so the sensor’s batteries can stay charged.

“The biggest issue with oceanographic instruments is battery power,” Edson explained. “Having a solar panel is pretty crucial and can make the deployment last longer.”

In order to eliminate the need for a research vessel, Edson said he would like to explore the possibility of attaching the “Mantaray” to other ships that already travel through the ocean every day. “If people are going through the ocean anyway and don’t mind strapping something to their boat, it might be an easy way to collect data,” he said.

Funding for this project came from a Provost’s Undergraduate Research and Creative Endeavors Award, and Edson did most of the work at Northeastern’s Marine Science Center in Nahant, Massachusetts, under the direction of professor Mark Patterson, who holds joint appointments in the College of Science and the College of Engineering.

Edson has a patent pending on the sensor through Northeastern’s Center for Research Innovation.