Read about her amazing science project below.
The world is facing a threatening problem of microplastics in the ocean. Microplastics, which are plastics the size of 10 um to 5 mm are accumulating everywhere, and its effect on the environment is disastrous. As of 2017, 8 million metric tons have been dumped into the ocean. Not only do the animals in the ocean get affected, humans do as well through a few different means. We can eat fish directly, or eat farm animals that depend on seafood byproducts, or we can eat vegetables that used the animal’s manure as fertilizer.
It's very difficult to separate microplastics from microorganisms and other particles in the ocean; using density, filtration, and chemical techniques have proven to be highly insufficient means of accurately isolating microplastics. To solve this problem, I have built an underwater ROV (remotely operated vehicle) which can analyze microplastics in the ocean. My hypothesis is that I can use infrared LED's of different wavelengths as a more affordable option compared to a commercial NIRS spectroscope that costs around $50,000 dollars. This is so I can have a more affordable and scalable system that would allow researchers to be able to cover more of the ocean floor quickly.
An innovative part of my ROV is that it does all of the chemical analysis in-situ, as opposed to having to collect samples. The reason why this is good, is because instead of having to take the samples out of the water, and take them all the way to a lab, I can just let the ROV do it, and this allows for much faster research. One key part of my system is the mathematical algorithm that is based on the pattern of the ratio of the absorption of plastics versus sand in different wavelengths of infrared light. My results, which I calibrated against some publicly available FT-IR data, are that you can see a clear difference between plastics versus metal, wood, or other organic chemical bonds such as those commonly found in materials such as seaweed, shellfish and other marine life.
My conclusion is that I can use infrared LED's as a more efficient way of finding plastics in the ocean. I suspect that microplastics, which have a range of different densities, are very likely aggregating into specific areas, much like gold deposits in the bend of a river, or floating plastics congregate into certain areas of gyres, and the Great Pacific Garbage patch on top of the ocean. If these ocean floor plastic repositories can be identified and categorized, then it will make the job of cleaning them up significantly easier, and much more financially feasible.
In a future phase of this project, I would like to develop an AUV (autonomous underwater vehicle) that utilizes my algorithm as part of the training model for machine learning for the system that can then pinpoint exactly where microplastics are aggregating along the ocean floor. Then these AUV's could optionally be deployed using swarming technology, that would be able to conduct faster spatial mapping of target regions, and use that information to inform the best way of cleaning the microplastics up.
Bio: Anna Du is twelve years old and attends Andover School of Montessori. This is her first year attending the science fair, and she did so because she loves marine mammals and other marine life. She's a big fan of both science and engineering and has attended ID Tech education camp every summer as well as attending engineering workshops at MIT Edgerton Center since she was five. She often travels with her family to Europe and Beijing, which is where her roots are, though she was born in Miami, near the ocean. She loves to visit the coastline all along New England. Her hobbies include ice skating, gardening, violin, and reading -- and one of her newest favorite books is My Friend, Salt.