Although many lab-scale experiments happen inside a flask, glassware can interfere with some reactions going on inside them. That’s why Qianqian Shi, a research fellow at Monash University working with Monash professor Wenlong Cheng and Duyang Zang of Northwestern Polytechnical University, performed this self-assembly reaction in midair. First, Shi levitates a drop of water using ultrasound waves coming out of the emitter above the drop. Then she adds a suspension containing gold nanocubes on th