Physicists from Friedrich-Alexander-Universität Erlangen-Nürnberg and Heinrich-Heine Universität Düsseldorf have demonstrated that demixing occurs in systems made up of macroscopic particles rotating in opposite directions and that particles turning in either a clockwise or counter-clockwise direction form homogeneous groups. The researchers used miniature robots manufactured using 3-D printing methods for their experiment. The results have now been published in the renowned journal Nature Communications.