This 12-year-old girl built a robot that can find microplastics in the ocean
This 12-year-old girl built a robot that can find microplastics in the ocean Anna Du was one of 30 Broadcom Masters finalists. (Rachael Lallensack/Broadcom Masters)
This 12-year-old girl built a robot that can find microplastics in the ocean
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Anna Du noticed plastic scattered on the shoreline. She was walking along Castle Island’s beach. That's in South Boston. She reached down to pick it up. She quickly realized there were many more tiny pieces than she could handle.

“When I realized how many pieces there were. It seemed impossible,” says Du. She was in sixth grade at the time.

Du approached the problem like any good scientist. First, she did a little research. That’s how she learned that 8 million metric tons of plastic end up in the oceans every year. And there's an additional 150 million metric tons that are already there.

Then she got to work building something that could help solve the issue. She built a remote-operated vehicle. It is referred to as an ROV. Her ROV could move through water. It could spot plastics on the ocean floor.

Du entered her ROV in the Broadcom Masters competition. It is one of the top science, technology, engineering and math (STEM) contests. It is for young students around the world. 

The competition is organized by the Broadcom Foundation and Society for Science and the Public. It has been running for eight years. This year, nearly 5,000 sixth, seventh and eighth graders were nominated. This was after they competed in regional science fairs.  Of those, 2,500 applied online for consideration. That pool was narrowed down to 300 projects dubbed “Broadcom Masters.” The top 30 finalists gathered in Washington, D.C. to showcase their projects. The top prize was $25,000. There were other cash prizes as well. 

Du’s ROV is made with PVC pipes. It is inspired by ROVs of all sorts. For instance, it is like the Curiosity lander that spies on the surface of Mars. It is also like the deep sea arctic Nereid ROV at Woods Hole Oceanographic Institution (WHOI). Du’s ROV has two separate systems. There is a navigation system and a detection system. The navigation system is pretty simple. It uses propellers to move through the water. It also uses a novel combination of fishing weights and foam pool floats that allow it to move up and down.

“The real invention here is the sensing.” That's according to Dana Yoerger. He is a roboticist and engineer. He works with WHOI’s Nereid. It is a ROV that travels great distances in the arctic. It hosts a suite of sensors on board. These include acoustic, chemical and biological sensors. Du was in awe of Nereid and nicknamed her ROV Nereid Jr. But her vehicle has a different skill set than its namesake. “The ROV is nicely done for a 12-year-old and hers is quite clever,” Yoerger adds.

The detection system is the “actually cool part.” That's according to Du. She uses a high resolution infrared camera along with three different kinds of light to spot the plastic. Du’s detection methods are comprised of two different wavelengths of infrared light. They illuminate the absorption spectra in microplastics. This makes them stand out from the sand and plant life. 

She also uses visible light to spot unnatural colors. These might make the plastics stand out. (Du was also one of ten finalists in the Discovery Education 3M Young Scientist Challenge this year. You can see a demo in her application video.) The apparatus doesn’t actually collect the microplastics. But it does identify where they are accumulating. She has applied for a patent on the functional elements of the ROV.

“She has an impressive basic kind of engineering instinct to break down a problem like this and then go after it,” says Casey Machado. She is also a WHOI engineer who works with Nereid. “She was able to follow that up with the technical work, construction and design to make a working prototype, which is very cool. It’s sounds simple, but it’s a level of thinking that’s really impressive.”

When Du first read about the challenge of locating ocean microplastics she found out that they are unlike the Great Pacific Garbage Patch. They are not floating on the surface. She knew that an ROV would be the most efficient tool for the task. Taking buckets and buckets of water samples and analyzing them in a lab could never be done to the scale needed. She needed a mobile lab that could find the plastics in-situ.

Du attends public events and workshops at MIT. She has been going since she was five years old. She picked up the engineering skills necessary to build her ROV from these sessions. She also learned skills from maker labs at local libraries and YouTube. 

She says actually getting her device to move through water well was tricky—even down to choosing the right kind of glue. It would be used to hold the PVC pipes together. Before she added fishing weights, the ROV would flip over. This happened when she tried to move it up and down. There was a lot of trial and error as she tested her ROV in Boston Harbor.

When asked about future plans, she mentions wanting to somehow address the effects of climate change.

“Especially with climate change happening all around the world, I think there’s a lot of problems that could be solved with new inventions,” says Du. “Right now, I’m mainly just focusing on plastics because there’s still a long way to go.”

Du credits her parents for fostering and supporting her interest in STEM. For years they have been taking her to MIT’s student outreach activities on weekends. She says she has been able to meet students and scientists there. As a result, she has her sights set on attending the university and becoming an engineer.

“I know I want to be an engineer because I like building things to help solve world problems,” says Du. “But I’m not sure what kind of engineer I want to be yet.”

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How do you think Anna's invention could be helpful on a global scale?
Write your answers in the comments section below

  • BenC-E2
    11/26/2018 - 04:20 p.m.

    so i like that some one is she is in 6th grade .
    i salute you !good for all earth and earth for all

  • NiH
    11/27/2018 - 03:13 p.m.

    She will solve a global problem by inventing a machine that helps detect plastic. Just like any inventor she tried over and over until she perfected her invention. This could end the great Pacific garbage patch and end the pain of the deaths of animal consuming and getting caught in plastic.

  • Sabina-E2
    11/29/2018 - 03:21 p.m.

    It is super cool that a 12 year old inventded that sort of thing.
    I also think it is very inspireing
    how do you think anna's invention could be helpful on a global scale? they could make more and people could maybe try it out and find some themselves.
    so I also think that it would be SUPER, SUPER, SUPER,
    useful to everyone, but especially the ocean.

  • Taylorp-eic
    11/30/2018 - 10:41 a.m.

    There is so much plastic in the ocean . She made a great invention and so now lots of more animals won't die ! I think we should also be taking care of our ocean a LOT more.

  • Tanner-E2
    12/03/2018 - 10:39 a.m.

    Anne Du is 12 years old and one day she was walking along the Castle island beach and noticed there was a bunch she started picking it up but then she relized there was way to many tiny peices of plastic. She approached the problem like any good scientist. She started with a little research. I think it is really cool that a 12 year old girl is beginning to solve a major problem.

  • Ashleym-bru
    12/06/2018 - 03:28 p.m.

    Acording to the artical"This 12-year-old girl built a robot that can find micro-plastics in the ocean",Anna's invention could be helpful on a global scale. One reason Anna's invention could be helpful is because she is saving animals in the ocean by getting all the plastic out to invent something but it is also helping the animals so they don't get hurt and that way they have a safe environment. Another reason Anna is helpful is because the robot that she is building is helping everyone around the world because the robot picks up plastic in the ocean everywhere around the world.

  • lblac-wim4
    12/13/2018 - 11:53 a.m.

    I think that Anna's invention could be helpful on a global scale because now we are rescuing a lot of animals. This is because Du's invention picks up trash that has been misplaced in the environment. And now animals are not getting tangled and stuck in them.

  • calon-wim5
    12/13/2018 - 12:45 p.m.

    I believe that Anna's invention could be extremely helpful on the global scale because if we build more and more robots to operate similarly, I think that we could be able to take care of our oceans and be able to lower the amount of plastic waste. I also think that if we make robots with a similar function, we could get more plastic waste, or maybe even oil remove that's in the ocean, locate it, and remove it. Or in other words, capture the oil. With this invention, we can really make the world a better place for us to live in.

  • DylanL-dec
    1/07/2019 - 10:36 a.m.

    That girl is a genius. What is her IQ?

  • ShaneS-3
    1/08/2019 - 02:34 p.m.

    The summary of this article is about a little girl who built a robot that can find micro plastics in the ocean. She built a robot that cleans plastic.The girl's name is Anna Du and she build wanted to pick up all the plastic in the water. Her remote operated vehicle, which was based off of many others, had done very well in her science fair. She built it with three different kind of lights and other ways to see plastic. She had trouble with getting it to go down without anchors. Anna DU built an actual working robot that can clean up plastic.

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