| Summary: | 碩士 === 國立中興大學 === 機械工程學系所 === 97 === This study reports results of visualization experiments on microdroplet generation in the microfluidics that contains a cross-junction structure on stationary and rotating chips. This PDMS microfabricated device utilizes the geometry of the channel junctions in addition to the flow rates to control the droplet sizes.
On the stationary experiments, oil(continuous phase) and water (dispersed phase) are injected into the cross-junction inlets to form water-in-oil emulsions for flow rate ranging from continuous phase( Qo )=0.01 - 0.4 ml/hr and dispersed phase (Qw)= 0.01 - 0.1 ml/hr, respectively. As a result, droplets with diameter as less than 10 μm can be produced without use of surfactants.
On the rotating experiments, oil(continuous phase) and water (dispersed phase) are injected into the cross-junction inlets to form water-in-oil emulsions by the centrifugal force. The droplet generation frequency as well as the droplet diameter manipulated by changing rotational speed. For rotational speed ranging from 500 - 1100 rpm, droplets of diameter from 100 to 166 µm can be generated in the microfluidics having channel width 300 µm, in which uniformity of the droplet size is measured within 3 % CV(Coefficient of variation).
|
|---|
