How to grow crystals when and where you want them

 

“Scientists ‘draw’ crystal patterns using laser light.

 

Call it a jazzed-up version of your childhood crystal-growing kit. Scientists have shown that, using lasers, they can grow crystals on demand1.

 

A wealth of everyday technologies — from smoke detectors to televisions — rely on the unique electrical properties of crystals. Yet these chemical structures, which are often grown from a small seed crystal, tend to form in unpredictable locations at unpredictable times.

 

To see whether they could standardize the crystal-growing process, Md Shahjahan and his colleagues at Michigan State University in East Lansing tried an alternative method of propagation. By aiming lasers at nanometre-scale gold particles, the researchers found that they could control exactly where and when the nanoparticles organized into a crystal structure — effectively ‘drawing’ their own crystal pattern while watching through a microscope [1].

 

Going forwards, the researchers hope to use multiple lasers at a time to carve out more intricate structures and perhaps create new materials. They also hope to test how their laboratory-grown crystals hold up when used in electronic devices. The results could be especially useful for pharmaceuticals and drug production.” [2]

 

1. This ability is possible because focused laser pulses heat specific, targeted gold nanoparticles, inducing localized melting and, upon rapid cooling, controlled assembly into crystal structures. This technique, which leverages photothermal effects for spatial and temporal control, allows researchers to steer nanoparticle organization in real-time, enabling precise, custom-patterned crystal growth.

Key Reasons for Success:

 

    Localized Heating: The laser generates heat exactly where it strikes the nanoparticles, causing them to move and assemble at specific, desired locations.

    On-Demand Assembly: Researchers can trigger the crystallization at precise times, as shown by Michigan State University researchers.

    Real-Time Visualization: Using high-speed microscopy, scientists can watch the process occur and adjust, allowing them to effectively "draw" patterns.

    Laser-Induced Interaction: The laser energy alters the behavior of the gold particles, enabling them to merge and form ordered structures.

 

    Nanoscale Control: The technique uses the unique properties of nanoparticles to achieve precise, customizable, and complex crystal arrangements, which are useful for potential new materials.

 

2. Nature 646, 1029 (2025)