Tiny self-assembling particles to create next-gen materials

Scientists have created microscopic self-assembling particles that can be manipulated using light and can serve as the next generation of building blocks in the making of synthetic materials.
"Our work turns the tiniest of particles from inflexible, Lego-like pieces into ones that can transform themselves into a range of shapes," said Stefano Sacanna, an assistant professor at the New York University.
"With the ability to change their contours, these particles mimic alterations that occur in nature," said Sacanna.
The research focused on engineering particles a micrometre in width - about 1/200th the width of a strand of human hair.
Specifically, it aimed to enhance the adaptability of colloids - small particles suspended within a fluid medium.

Such everyday items such as paint, milk, gelatin, glass, and porcelain are composed of colloidal dispersions, but it is their potential to control the flow of light that has scientists focused on creating exotic colloidal geometries.

By triggering specific morphological changes in the singular colloidal unit, researchers hope to advance colloidal crystal engineering.
The scientists discovered that metallic particles encased in oil droplets were tethered by many chemical bonds.
Breaking those tethers via a photocatalytic reaction - in which the absorption of light spurs a chemical response - caused the metallic particle to free itself, producing an overall shape change.

In other words, shining a light on a simple crystal allowed the scientists to create a material that transforms its microstructure.