Straight-through microchannel devices for generating monodisperse emulsion droplets several microns in size

• Published in: Microfluidics and nanofluidics Vol. 4; no. 3; pp. 167 - 177
• Main Authors: Kobayashi, Isao, Takano, Takayuki, Maeda, Ryutaro, Wada, Yoshihiro, Uemura, Kunihiko, Nakajima, Mitsutoshi
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer-Verlag 01-03-2008; Springer; Springer Nature B.V
• Subjects: Analytical Chemistry; Applied fluid mechanics; Applied sciences; Biological and medical sciences; Biomedical Engineering and Bioengineering; Chemical engineering; Chemistry; Colloidal state and disperse state; Emulsions; Emulsions. Microemulsions. Foams; Engineering; Engineering Fluid Dynamics; Exact sciences and technology; Fat industries; Fluid dynamics; Fluidics; Food industries; Fundamental and applied biological sciences. Psychology; Fundamental areas of phenomenology (including applications); General and physical chemistry; Membrane separation (reverse osmosis, dialysis...); Nanotechnology and Microengineering; Physics; Research Paper; Monodisperse emulsion; Straight-through microchannel; Microchannel emulsification; Droplet generation; Oblong channel; Water oil emulsion; Test facilities; Emulsification; Oil water emulsion; Experimental study; Microparticles; Fabrication; Microchannel; Monodispersed particle; Oblong channel; Microchannel emulsification; Droplets; Microstructure; Microfluidics
• ISSN: 1613-4982; 1613-4990
• DOI: 10.1007/s10404-007-0167-2

The authors recently proposed a promising technique for producing monodisperse emulsions using a straight-through microchannel (MC) device composed of an array of microfabricated oblong holes. This research developed new straight-through MC devices with tens of thousands of oblong channels of several microns in size on a silicon-on-insulator plate, and investigated the emulsification characteristics using the microfabricated straight-through MC devices. Monodisperse oil-in-water (O/W) and W/O emulsions with average droplet diameters of 4.4–9.8 μm and coefficients of variation of less than 6% were stably produced using surface-treated straight-through MC devices that included uniformly sized oblong channels with equivalent diameters of 1.7–5.4 μm. The droplet size of the resultant emulsions depended greatly on the size of the preceding oblong channels. The emulsification process using the straight-through MC devices developed in this research had very high apparent energy efficiencies of 47–60%, defined as (actual energy input applied to droplet generation/theoretical minimum energy input necessary for making droplets) × 100. Straight-through MC devices with numerous oblong microfluidic channels also have great potential for increasing the productivity of monodisperse fine emulsions.