title: A microfluidic chip for formation and collection of emulsion droplets utilizing active pneumatic micro-choppers and micro-switches.
abstract: The formation of emulsification droplets is crucial for many industrial applications. This paper reports a new microfluidic chip capable of formation and collection of micro-droplets in liquids for emulsion applications. This microfluidic chip comprising microchannels, a micro-chopper and a micro-switch was fabricated by using micro-electro-mechanical-systems (MEMS) technology. The microfluidic chip can generate uniform droplets with tunable sizes by using combination of flow-focusing and liquid-chopping techniques. The droplet size can be actively fine-tuned by controlling either the relative sheath/sample flow velocity ratios or the chopping frequency. The generated droplets can be then sorted to a specific collection area utilizing an active pneumatic micro-switch formed with three micro-valves. Experimental data showed that the olive oil and sodium-alginate (Na-alginate) droplets with diameters ranging from 3 mum to 70 mum with a variation less than 14% is successfully generated and collected. The development of this microfluidic system can be promising for emulsion, drug delivery and nano-medicine applications.
authors.affiliation: Department of Engineering Science, National Cheng Kung University, Tainan, Taiwan.
authors.forename: Chia-Wei
authors.initials: CW
authors.lastname: Lai
authors.forename: Yen-Heng
authors.initials: YH
authors.lastname: Lin
authors.forename: Gwo-Bin
authors.initials: GB
authors.lastname: Lee
mesh_terms: D000464:Alginates / Q000737:chemistry / Q000648:ultrastructure; D004655:Emulsions / Q000032:analysis* / Q000737:chemistry*; D004867:Equipment Design; D046210:Microfluidic Analytical Techniques / Q000295:instrumentation* / Q000379:methods; D044085:Microfluidics / Q000295:instrumentation*; D000069463:Olive Oil; D010938:Plant Oils / Q000737:chemistry; D011312:Pressure; D014867:Water / Q000737:chemistry
chemical_list: D000464:Alginates; D004655:Emulsions; D000069463:Olive Oil; D010938:Plant Oils; D014867:Water