Phys.org  December 17, 2021 Researchers in the Netherlands have demonstrated that by illuminating a solution of barium carbonate and silicon with UV light they can control when and which structures arise at the micrometer scale. As soon as barium carbonate crystals form in the solution, the silicon joins in and precipitates together with the crystals, thus giving rise to the unusual shapes. A tiny bit of CO2 gas in the solution starts this process. If one could ensure that CO2 arises at the exact location and time desired, this would result in an on-off switch for the chemical reaction. Using […]