Ultrasound against microplastics: two Texas teenagers invent a 'pen' to purify water

©Sören Funk via Unsplash

It all started with a simple, almost naive question: what if sound could help clean water? This isn't a philosophical question, but the starting point of a very concrete research project by two Texan high school students who, far from laboratories and multi-million dollar funding, decided to tackle one of the most challenging environmental problems to solve.

Microplastics, fragments invisible to the naked eye, escape traditional filtration systems and end up everywhere: in rivers, in the seas and in our drinking water. From there, they penetrate our bodies, passing through tissues until they reach the bloodstream. This is the field in which Victoria Ou and Justin Huang, both 17, decided to work, starting with an idea as simple as it is counter-intuitive: not to trap plastic, but to repel it.

Physics and environment

Instead of using ever finer filters, doomed to clog up or become increasingly expensive, the two students chose an entirely different path. They used carefully calibrated, high-frequency acoustic waves capable of exerting pressure on the microplastics suspended in the water. The result is disconcertingly simple: the particles are pushed towards each other, aggregate, swell and eventually become filterable.

In laboratory tests, this technique removed over 80% of microplastics in a single filtration, without the use of chemicals or sophisticated membranes. The prototype, about the size of a pen, operates with low energy consumption and could, at least on paper, be used in contexts far from major infrastructure, in rural areas or regions affected by water shortages.

This is neither science fiction nor a vague promise. It's applied physics, and that's precisely what makes this discovery so interesting: a well-known principle, ultrasound, exploited in an innovative way, to tackle a very real problem.

Interest from the international scientific community

Victoria Ou and Justin Huang's work has not gone unnoticed. Their project won an award of $50,000 at the Regeneron International Science and Engineering Fair, one of the world's most prestigious science competitions for students. The prize doesn't pinpoint a point of arrival, but rather a point of departure.

The device is still in the experimental stage. There is no version ready for installation in drinking water networks or directly in private homes, and further studies will be needed to understand how this technology could be used in the future and how it could work on a large scale, under conditions other than those of a controlled laboratory. But we now know that an alternative route exists, and that it deserves to be explored.

Source : ISEF

(©GreenMe.it 2026/Managing editor: Selma Keshkire - The Press Junction/Picture: Sören Funk via Unsplash)