Hot crystals through laser light

Published on October 31, 2023
Category Self-Organizing Matter
Timelapse images and SEM image of the nucleation and growth of a single CaCO3 crystal using NIR laser light, the red dashed circle indicates the focal spot of the NIR laser.

Shells, skeletons, and bones are all made of crystals. To function properly these crystals need to grow at the right time and place. Inspired by these natural processes, AMOLF researchers have developed a new method to control crystallization under artificial conditions using near-infrared laser light.

With the help of the technicians Marko Kamp and Hinco Schoenmaker, PhD student Marloes Bistervels has built a special laser setup that locally heats up an aqueous solution. Within a second the temperature in the hotspot increases to almost 100 degrees Celsius. This local heating consequently causes the formation of special crystals that decrease in solubility with increasing temperature. By controlling the power of the laser beam, Bistervels can start, stop, and steer the formation process, thereby determining precisely where and how crystals will form. Moving the laser beam she deposits a line of crystals, such that she can ’write’ patterns.

Three different CaCO3 polymorph positioned next to each other using NIR light induced nucleation.

This light-induced crystallization works for many different sorts of crystals that are relevant in biology, such as crystals that form in bones, shells, and skeletons. The ability to control crystal growth in space and time is promising for the development of next-generation functional materials that hold unique optical and mechanical properties.

The recent results booked by Bistervels are aimed at achieving spatiotemporal control over self-assembly processes using light techniques. Over the past two years she extended the toolbox to control the crystallization process with different light sources applied on different systems. For instance, instead of using ultraviolet (UV) light, she now uses near-infrared (NIR) light without the use photo sensitive molecules. Hence, a cleaner process. In addition, the technique is here applied on pure biorelevant crystals, instead of synthetic nanocomposites.

Read related news Crystals beneath a sunbed (December 14th, 2021).

M.H. Bistervels, B. Antalicz, M. Kamp, H. Schoenmaker and W.L. Noorduin, Light-driven nucleation, growth, and patterning of biorelevant crystals using resonant near-infrared laser heating, Nature Communications, 14 – Issue 1 p. 6350: 1- 9, 10-10 (2023).

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