Mass production of shaped particles through vortex ring freezing

• Published in: Nature communications 2016-08, Vol.7 (1), p.12401-12401, Article 12401
• Main Authors: An, Duo, Warning, Alex, Yancey, Kenneth G., Chang, Chun-Ti, Kern, Vanessa R., Datta, Ashim K., Steen, Paul H., Luo, Dan, Ma, Minglin
• Format: Article
• Language: English
• Subjects: 13; 14/19; 38; 639/166; 639/301; 639/301/54; Cell culture; Humanities and Social Sciences; multidisciplinary; Nanoparticles; Science; Science (multidisciplinary); Viscosity
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/ncomms12401

A vortex ring is a torus-shaped fluidic vortex. During its formation, the fluid experiences a rich variety of intriguing geometrical intermediates from spherical to toroidal. Here we show that these constantly changing intermediates can be ‘frozen’ at controlled time points into particles with various unusual and unprecedented shapes. These novel vortex ring-derived particles, are mass-produced by employing a simple and inexpensive electrospraying technique, with their sizes well controlled from hundreds of microns to millimetres. Guided further by theoretical analyses and a laminar multiphase fluid flow simulation, we show that this freezing approach is applicable to a broad range of materials from organic polysaccharides to inorganic nanoparticles. We demonstrate the unique advantages of these vortex ring-derived particles in several applications including cell encapsulation, three-dimensional cell culture, and cell-free protein production. Moreover, compartmentalization and ordered-structures composed of these novel particles are all achieved, creating opportunities to engineer more sophisticated hierarchical materials. The evolution of vortex flow exhibits a rich spectrum of complicated geometries. Here, An et al . utilize these features to control and mass produce inorganic and organic particles via an electrospraying process, whereby the shape of vortex rings translates into particles during a freezing process.