Yidian Liu is Co-Founder and COO of PolyGone Systems, a Princeton University spinout cleantech company removing microplastic pollutants from waterways. She is a Forbes 30 Under 30 Fellow recognized for her innovative environmental solutions.

Yidian holds a Master's degree in Architecture from Princeton University and a Bachelor's from Syracuse University. She co-founded PolyGone in 2021 with Nathaniel Banks after their joint thesis project on aquatic plastic pollution.

Since 2021, Yidian has secured over $2.4 million in state and federal financing from organizations including NJCSIT, NJEDA, NSF, and NOAA. She has represented PolyGone as a keynote speaker at sustainability events including NYC Circular City Week and Delaware Water Congress.

PolyGone won the Cleantech Open 2025 national competition and raised a $4 million Seed round led by FYRFLY Venture Partners in February 2026. The company operates the first microplastic filtration system built into a wastewater treatment plant in the United States.

PolyGone's patented filtration systems remove 98% of toxic microplastics from water at 90% lower cost than alternative methods. The company has completed pilots at polluted lakes, rivers, and a 40 million gallon per day wastewater treatment facility.