Small levitating clusters of an arbitrary number of monodisperse droplets

Our new paper in J. Phys. Chem Lett. (Impact factor = 9.35) deals with a new technique to create a levitating ordered cluster of any arbitrary small number of microdroplets. Before, only large and polydisperse clusters were created, so the publication marks a significant accomplishment. The amazing phenomenon of the droplet cluster was discovered by Dr. A. Fedorets from Tyumen University (Russia). Tyumen is a remote city in Siberia. Various aspects of droplet clusters are being investigated by our international group, involving colleagues from Tyumen, Moscow, and Ariel University in Israel. It is anticipated that the ability to trace individual droplets and biological and chemical processes in them will provide new opportunities for lab-on-a chip droplet microreactors, new insights on the origin of Life on earth, as well as new understanding of self-organization and self-assembly in water.

A. A. Fedorets, M. Frenkel, E. Bormashenko, and M. Nosonovsky, 2017. Small Levitating Ordered Droplet Clusters: Stability, Symmetry, and Voronoi Entropy, The Journal of Physical Chemistry Letters, 2017, 8, pp 5599–5602, DOI: 10.1021/acs.jpclett.7b02657.
Link to the PDF file

ABSTRACT: A method to generate levitating monodisperse microdroplet clusters with an arbitrary number of identical droplets is presented. Clusters with 1−28 droplets levitate over a locally heated water layer in an ascending vapor-air jet. Due to the attraction to the center of the heated area combined with aerodynamic repulsion between the droplets, the clusters form structures that are quite diverse and different from densest packing of hard spheres. The clusters self-organize into stable and reproducible configurations dependent on the number of droplets while independent of the droplets’ size. The central parts of larger clusters reproduce the shape of smaller clusters. The ability to synthesize stable clusters with a given number of droplets is important for tracing droplets, which is crucial for potential applications such as microreactors and for chemical analysis of small volumes of liquid.

A cluster of 11 droplets (G3S11N11) with a three-droplet nucleus (G3)