New York University researchers develop light controlled method to assemble and dissolve microscopic crystals in real time

NYU researchers develop a light-sensitive method to assemble, dissolve, and reshape colloidal crystals in real time using photoacids and illumination.

By: AXL Media

Published: Mar 2, 2026, 10:48 AM EST

Source: The information in this article was sourced from ScienceDaily

Light Driven Microscale Organization

Researchers at New York University have reported a breakthrough in material science by turning light into a precision tool for controlling crystal formation. Traditionally, controlling the exact timing and location of crystallization has been a significant challenge for scientists, as crystals often form spontaneously according to set environmental conditions. The new method, published in the journal Chem, allows for the real time adjustment of these processes, providing a straightforward and reversible technique for building microscopic structures.

The Role of Photoacids in Particle Interaction

The core of this new technology involves the use of light sensitive molecules known as photoacids. When these molecules are added to a liquid containing colloidal particles and exposed to light, they undergo a chemical change that increases the acidity of the surrounding fluid. This shift in acidity alters the electric charge on the surface of the particles, allowing researchers to toggle between attraction and repulsion. By manipulating these charges, the team can effectively program whether particles stick together to form a crystal or push apart to remain in a liquid state.

Real Time Sculpting and Uniformity

Through a series of experiments and computer simulations, the NYU team demonstrated that the brightness and pattern of light can be used to "sculpt" structures with remarkable precision. Researchers were able to shoot light at random blobs of particles and observe them ordering themselves into uniform crystals under a microscope. Conversely, they could cause specific sections of a crystal to melt by simply unsticking the particles in a targeted spot. This level of control allows for the creation of larger and more intricate assemblies than previously possible with static methods.