The fabrication, motion and behavior of small droplets are subjects under
considerable current study. The possible applications include using droplets as actuators
to enhance mixing, as chemical reactors and the formation of emulsions. Microfluidics
provides a convenient means of producing droplets at the micro scale. The study is
currently dominated by spherical systems where droplets are consistently spherical in
nature. Various methods and geometries have been tested for fabricating these droplets
but little research has been conducted towards producing non-circular droplets. While
the fabrication of non-spherical droplets has been reported before control over their
shape remains difficult to achieve.
In this thesis, we present a method to fabricate droplets using shear focusing in
an oil medium alternatively from two channels facing each other. The droplets produced
are non-circular in shape, and their shape dynamically alters as they travel in the
microfluidic channel. The size of the droplets can be controlled by the ratio of oil and
water flow rates.
Microscopic images have been presented that show the non-spherical shape of
the droplets at the point of fabrication. Images taken at two points further along the microfluidic channel show how the shapes of these droplets change as they travel in the
channel. There were three regimes of droplet shapes, circular, triangular and rectangular
shapes that were determined by the packing ratio of water droplet in oil phase in
microfluidic channels. All droplets formed in this experiment were monodispersed.
| Identifer | oai:union.ndltd.org:tamu.edu/oai:repository.tamu.edu:1969.1/ETD-TAMU-2726 |
| Date | 15 May 2009 |
| Creators | Mehrotra, Rajat |
| Contributors | Kameoka, Jun |
| Source Sets | Texas A and M University |
| Language | en_US |
| Detected Language | English |
| Type | Book, Thesis, Electronic Thesis, text |
| Format | electronic, application/pdf, born digital |
Page generated in 0.0019 seconds