Versatile methodology for generating size-controlled composite micrometer beads capsulating nanomaterials

Our developmental investigations into aerodynamically assisted jetting have previously shown great promise (Jayasinghe and Suter in Micro and Nano Letts., 2006, 1, 35) in materials science and engineering. This processing approach is currently undergoing rapid development where it will join other related jet-based processes such as ink-jet printing and electrospraying with which the precision deposition of droplet residues (containing a wide variety of micro- and nanomaterials) is most useful in micro- and nanosciences. The ability for capsulating nanomaterials (having a mean particulate size of 5 nm) as micrometer-sized composite beads is demonstrated. Investigations reported here show the influence of the applied aerodynamic forces to the chamber or flow rate to the needle, respectively, having effect on the generated composite bead sizes, their distributions and on the jetting characteristics. These investigations imply the versatility of this processing science for capsulating a wide variety of nano-sized materials as composite beads for applications ranging from the formation of stable emulsions to a route for controlled delivery of drugs, which would be most useful to the pharmaceutical industry.