The newly published article in Chemical Science, the flagship journal of the Royal Society of Chemistry, reports experimental results on using levitating microdroplet clusters as chemical reactors. The reaction is between melamine (M) and cyanuric acid (CA). First, a solution of M was injected into the cluster, so that several dozens of droplets with M were formed. Then, a solution of cyanuric acid was injected into the cluster, so that droplets with CA were formed as well. After that, many droplets coalesced, causing a chemical reaction M + CA → melamine cyanurate (MC), with sedimentation of MC crystals inside microdroplets thus forming luminescent crystals that could be observed as flashing points.
This is the first observation of a chemical reaction in a levitating droplet cluster. The observation proves that microdroplets can be used as chemical micro-reactors. The cluster is an array of several dozens of microreactors. The expectation is that chemical reactions could have different kinetics in levitating microdroplets compared with those in the bulk. Merging droplets can also be used as a foundation of a chemical computing device.
To demonstrate the potential of droplet clusters for information processing, flashing was converted into music.
The video with sound is below. The droplet images are colored by a machine learning algorithm with different colors representing different types of rotational behavior of crystals.
See also: https://sites.uwm.edu/nosonovs/2022/06/24/droplet-microcluster-as-a-chemical-microreactor/