In this exclusive interview, co-founder and CTO of PolyGone Systems, Nathanial Banks, discusses the groundbreaking technology behind the biomimetic Artificial Root microplastic collection device. The technology is poised to tackle microplastics in water bodies, including oceans and rivers, with its unique design, exceptional efficacy, and potential to transform the landscape of environmental monitoring. Nathanial Banks speaks about Artificial Root's inception as a joint thesis project to real-world applications and partnerships, as well as the PolyGone Systems' journey in revolutionizing microplastic pollution solutions.
Can you tell us briefly about your role and the history behind PolyGone Systems?
As the co-founder and CTO of PolyGone Systems, I oversee the technology development, prototyping, and pilot project executions. I am working closely with a team of chemical and mechanical engineers to optimize our filter design, fabricate supporting systems of the filter, and conduct sample analysis to test its effectiveness.
PolyGone systems began as part of our (Yidian Liu & Nathaniel Banks’) joint thesis research at Princeton University. Our research focused on analyzing aquatic pollutants and waste infrastructure, during which we discovered that while large plastic items and pollutants were being collected and recycled from waterways, there were no systems in place to capture or recycle the trillions of microplastics entering our oceans and drinking water each year. This concerned us, so we decided to address it. The IP we developed during the thesis project later became the foundation for our business.
Can you talk about the extent of plastic pollution in our oceans and its harmful effects?
In 2010 alone, between 4-12 million metric tons of plastic waste entered the world’s oceans, according to an article in Science.
Rivers play a significant role in transporting this plastic to the ocean, with over 1,000 rivers accounting for 80% of annual ocean emissions. When macroplastic debris enters a river, they degrade into smaller microplastic fragments, as small as 5 mm in diameter. Microplastics are rapidly becoming a global concern, as they can easily be ingested, introducing potentially hazardous and carcinogenic additives into the diets of wildlife and humans. Due to their small size, they are incredibly difficult to capture from water bodies without significantly disrupting aquatic ecosystems. Therefore, once in aquatic ecosystems, microplastics tend to remain and accumulate, resulting in a growing pervasiveness and steady increase in microplastic concentrations across the world’s rivers, lakes, and oceans.
Notably, microplastics have been identified in approximately 92% of US tap water, salt, beer, and human blood, with the average person potentially ingesting approximately a credit card’s worth of plastic each week. This creates a critical need for new infrastructure to remove these harmful contaminants from our waterways.
Why do plastics become hard to detect in the ocean?
Microplastics are plastic materials that are smaller than 5 mm in diameter. Primary microplastics typically enter the environment directly by using plastic products in a household.
Secondary microplastics form from the breakdown of larger plastic items, such as disposable plastic cups and utensils, into microplastic fragments due to weathering, abrasion, and UV degradation.
Since both types of microplastics are highly durable and not biodegradable, they can persist in aquatic environments for potentially hundreds of years. Under UV exposure, plastic particles continue to break into smaller pieces of nanoplastics, making them a particularly challenging pollutant to effectively monitor and manage.
As the plastics keep breaking down, the microplastics' scale, shape, and color make many invisible to the naked eye.
Microplastics are generally inert and do not intrinsically react to the magnetic and chemical treatment processes used in wastewater treatment facilities, making them challenging to sequester without using fine and heavy-duty membrane filters. Many water channels, including open channels in rural areas or with urban runoff during stormwater surges, do not go through the water treatment process.
Can you tell us about your biomimetic filtration system, the Artificial Root, and how it works?
Our biomimetic ‘Artificial Root’ filter is modeled on the fibrous structure of aquatic plant roots that passively adhere and collect small sediments from water without using electricity.
Due to its fibrous structure and hydrophobic quality, the filter physically entraps small aquatic sediments from flowing water, including microplastics.
The artificial root filter is designed to minimally disrupt aquatic ecosystems by its unique position in the water column.
The Artificial Root filter. Image Credit: PolyGone Systems, Inc.
Since most plastic debris is less dense than water, most plastic and microplastic waste is found in the upper strata of typical riverine water columns. The artificial root is arrayed on the underside of our device but does not extend to the bottom of the river. This greatly narrows the range of aquatic sediments captured by our device and enables denser sediments and aquatic wildlife to navigate below it.
The filters can also be arrayed loosely to provide navigable passageways for fish and other aquatic organisms to avoid entrapment in the filter media.
The artificial filters are hosted by our modular floating station, nicknamed “The Plastic Hunter”, which consists of a pontoon frame and an array of these artificial root filters designated to monitor and capture microplastic particles in the water.
The Plastic Hunter was created to be affordable and environmentally friendly in hopes of having these devices operating at wastewater treatment plants and drinking water treatment channels. We aim to remove microplastics from water channels such as rivers and lakes before they enter broader aquatic environments and drinking water sources.
How does your microplastic collection device differ from existing microplastic detection and removal methods?
Most river trash collectors, such as the Seabin or regular floating barriers, do not capture microplastic pollutants smaller than 1 mm. Our filter fulfilled the technical gap.
Industrial filters, such as the disk membranes, can capture microplastics, but they are expensive to install, estimated at up to $300,000 per unit, and require skilled labor to operate and maintain.
Our device is significantly more affordable, and our filter is versatile enough to be deployed in rural areas or during stormwater surges, where water is typically unfiltered.
The device is affordable to install and maintain, utilizing relatively cheap materials like silicone fibers to comprise the filter media and requiring no electricity, mechanical systems, or surrounding infrastructure to operate.
What specific types of microplastics can your device identify and collect?
Our filters mainly target microplastic particles between 100 microns and 1 mm in diameter, including pellets, films, fragments, and fibers.
How do you ensure the accuracy and reliability of your microplastic collection device's data?
Our team has developed a staining and fluorescence imaging protocol that enables us to identify difficult or impossible microplastics using conventional visual analysis methods. For our proposed field deployments, our team plans to utilize this staining and imaging protocol to rapidly analyze field samples for microplastic concentrations without the intensive labor and human error risks associated with manual counting protocols. Our team also utilized the FTIR imaging method for additional verification.
What challenges did you face during the development of the microplastic collection device, and how did you overcome them?
After our initial field tests with the coconut fiber filters, we identified a few significant improvements that needed to be made. Organic materials, including plants, algae, and insects, seemed to accumulate substantially on the prototype’s fiber brushes over time, which makes the filter hard to collect and reuse. We used silicone fiber as the raw brush material to make it less impactful to aquatic life. The hydrophobic nature of silicone inhibits biofilm growth along the filter, drastically elongating the operational capacity of the filter. Since the change of brushes, we have seen 72% removal success within the first 24 hours of lab tank tests.
How scalable is your microplastic collection device, and what are your plans for implementing it on a larger scale for environmental monitoring?
The microplastic problem is huge, with over 10,000 rivers releasing plastic pollutants worldwide.
We aim to address the problem strategically in areas of critical contamination and deploy our devices systematically in streams, rivers, lakes, and marinas.
Our filters are easy to install, cost-effective, and do not require any electricity. These advantages have enabled its application in industrial water treatment sites and rural areas lacking appropriate waste infrastructure, where plastic waste often leaks into the ocean.
Please share real-world applications or success stories where your microplastic collection device has positively impacted the environment.
At the beginning of our formation, we formed a strong partnership with the Willistown Conservation Trust, which allowed us to collaborate and complete our first field test deployment at the Ashbridge Preserve, a Delaware tributary area.
We identified Ridley Creek within the preserve as our test site because it is downstream of a wastewater effluent channel and was found by WCT researchers to be contaminated with microplastics.
Filters were tied to stakes on either side of the stream, covering most of the stream’s width, and were left to capture microplastic particles for one month.
Upon removal, we were excited to find various microplastics sticking to our filters, including pellets, fibers, and films below 1 mm in diameter.
We also identified several challenges with our previous filter material, coconut fiber, which was prone to biofilm formation. We thereby adapted to using silicone as our new fiber material.
In what ways do you envision a collaboration with researchers, environmental agencies, or communities to improve and deploy your microplastic collection device?
Besides WCT, we are collaborating with Prof. Tae Seok Moon at Washington University St. Louis, Energy, Environmental and Chemical Engineering Department to potentially upcycle any microplastic we collect, turning waste into a resource. We formed a collaboration project to capture microplastic from the NY and NJ watershed using our filters and deliver them to their lab for upcycling.
Finally, PolyGone is performing a full-scale pilot deployment at the ACUA’s wastewater treatment facility in Atlantic City. We are building a full-sized pilot project alongside an education pavilion at the equalization basin right before the water goes to the ocean.
This project aims to test the efficacy of our system at a larger scale and showcase the process for public education.
How do you plan to raise awareness about the issue of microplastic pollution and the importance of using such collection devices among the general public and policymakers?
My co-founder and I both have a strong design background. We believe that educating others about the plastic problem is just as important as solving the problem itself.
We are raising awareness about microplastic pollution through our architectural installation, Tides of Plastic, at the Shenzhen Biennale. We used filters to form the structure's base and magnified the effect of fluorescent microplastic particles “shining” under the UV light.
With this installation, the microplastics would now resemble stars shining in the dark sky at night to the naked eye. This exhibition attracts thousands of visitors daily during the exhibition period and stimulates impactful discussions around microplastic pollution and protecting our oceans.
On the other hand, we want to promote a better understanding of microplastic pollutants in the water industry. Our team regularly attends conferences and expos on water treatment, aquatic plastics, and marine debris to showcase our research to potential academic and industrial partners. We also interview microplastic experts and collaborate with professional writers to produce short articles and videos on specific microplastic and aquatic pollution topics. These videos and articles will be featured on our website under a learning tab for the general public to access.
Are there any ongoing research and development initiatives within your company?
Currently, we are testing new formulations of the raw silicone material to be more hydrophobic and attract more plastic. In addition, we are building a portable cleaning device for cleaning artificial root filters.
Where can readers find more information?
https://polygonesystems.com/product
https://polygonesystems.com/research/shenzhen-biennale
https://polygonesystems.com/research/field-test-ashbridge-preserve
https://polygonesystems.com/research/blog-post-title-three-fd2h2
About Nathaniel Banks
Nathaniel Banks is a trained architectural, landscape, and product designer and is currently the CTO and co-founder of PolyGone Systems, Inc., an environmental-tech company specializing in removing microplastic contaminants from waterways.
Nathaniel holds a Master’s degree in Architecture from Princeton University. He is passionate about applying design and representational strategies to broaden awareness and develop innovative solutions to pressing environmental challenges. His ongoing interdisciplinary collaboration with researchers in advanced chemistry, hydrological engineering, and environmental policy has enabled him to design, fabricate, and pilot novel filtration technologies to address the emerging microplastic crisis.
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