NYU Scientists Use Light to Control Crystal Formation

Their research provides a simple and reversible method for forming crystals that can be used to develop a new generation of adaptable materials.

Published on Feb. 25, 2026

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NYU scientists have developed a new technique that uses light to precisely control how tiny particles organize themselves into crystals. Their research, published in the Cell Press journal Chem, provides a simple and reversible method for forming crystals that can be used to develop a new generation of adaptable materials.

Why it matters

Crystals are the building blocks of many advanced materials, including those used in optical and photonic technologies like sensors and lasers. However, it has been difficult to manipulate the formation of crystals. This new light-based technique gives researchers unprecedented control over the crystal formation process, opening up new possibilities for creating reconfigurable and adaptable materials.

The details

The researchers added light-sensitive molecules, or photoacids, to a solution of liquid and colloidal particles. When light is shined on the photoacids, they temporarily become more acidic, which influences how they interact with the surfaces of the colloidal particles. This changes the electric charge on the particles, directly controlling whether they attract or repel each other. By adjusting the light intensity, timing, and spatial patterns, the researchers were able to trigger crystals to form or melt on demand, control where crystallization happens, reshape and "sculpt" crystals, and improve their order and size.

  • The research was published in the February 2026 issue of the Cell Press journal Chem.

The players

Stefano Sacanna

Professor of chemistry at NYU and lead author of the study.

Steven van Kesteren

Postdoctoral researcher at ETH Zürich who conducted this work at NYU in Sacanna's lab.

Glen Hocky

Associate professor of chemistry and faculty member at the Simons Center for Computational Physical Chemistry at NYU.

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What they’re saying

“Essentially, we used light as a remote control to program how matter organizes itself at the microscale.”

— Stefano Sacanna, Professor of chemistry at NYU (Chem)

“Using our photoacid gave us a surprising level of control over the attraction between particles. Just turning the light up or down a little made the difference between the particle fully sticking or being fully free.”

— Steven van Kesteren, Postdoctoral researcher at ETH Zürich (Chem)

“Our approach brings us closer to dynamic, programmable colloidal materials that can be reconfigured on demand. This system also allows us to test a number of predictions on how self-assembly should behave when interactions between particles or molecules are changing across space or time.”

— Glen Hocky, Associate professor of chemistry at NYU (Chem)

What’s next

The researchers plan to further explore the potential applications of their light-based crystal control technique, including the development of reconfigurable optical coatings, adaptive sensors, and next-generation display and information storage technologies.

The takeaway

This new light-based technique for controlling crystal formation represents a significant advance in the field of colloidal materials, providing researchers with unprecedented control over the self-assembly of particles at the microscale. The ability to dynamically program the structure and properties of these materials opens up exciting possibilities for the development of a new generation of adaptable and reconfigurable materials.