A new process for creating specifically patterned microstructures could lead to new catalysts and optoelectronic devices.
To make the materials, Rolf Hempelmann of Saarland University in Saarbrücken, Germany, and his colleagues prepared tiny latex spheres made of the polymer polybutylacrylate, each with a diameter of about 200 nanometers and a negatively charged surface.
When the scientists placed enough of the mutually repelling spheres in water, they settled into a uniform, three-dimensional lattice. This pattern was easily disrupted, so the team added the chemical acrylamide and applied ultraviolet light. This turned the liquid into a gel, locking the lattice in place.