Liquid transport in micron and submicron size channels.

Format:

Book

Thesis/Dissertation

Author/Creator:

Pfahler, Joseph Norman.

Contributor:

Bau, Haim H., advisor.

University of Pennsylvania.

Language:

English

Subjects (All):

Magnetohydrodynamics.

Mechanical engineering.

0548.

0759.

Penn dissertations--Mechanical engineering.

Mechanical engineering--Penn dissertations.

Penn dissertations--Applied mechanics.

Applied mechanics--Penn dissertations.

Local Subjects:

Penn dissertations--Mechanical engineering.

Mechanical engineering--Penn dissertations.

Penn dissertations--Applied mechanics.

Applied mechanics--Penn dissertations.

0548.

0759.

Physical Description:

129 pages

Contained In:

Dissertation Abstracts International 53-05B.

System Details:

Mode of access: World Wide Web.

text file

Summary:

An experimental investigation was conducted to access the rheology and flow dynamics of Newtonian and non-Newtonian fluids in small uniform channels. Channels with depths ranging from 0.5 $\mu$m to 40 $\mu$m were etched in silicon using standard planar photolithographic techniques. An experimental apparatus was constructed and a procedure devised to measure the flow resistance of the channels. Great care was taken so that the measurements were accurate and repeatable. A reduced flow resistance was demonstrated for Newtonian fluids as the channel's smallest characteristic length decreased from 40 $\mu$m to 0.5 $\mu$m. A viscosity model that includes wall effects was created to explain the data but had limited success. Stagnation flow, corner flow and exit flow were visualized using fluorescent micro-beads in 20 $\mu$m deep X 40 $\mu$m wide structures. Moffatt's eddies were observed in corners at a Reynolds number of 75 and exit vortices were seen at a Reynolds number of 25. The non-Newtonian fluids included serum, plasma, washed red blood cells, and whole blood. A comparative study was performed with different fluids in the same channel. These fluids behaved generally as expected with whole blood offering the most flow resistance. These fluids showed a distinct shear thickening at the lower Reynolds numbers. Despite the low Reynolds numbers, the shear rate was relatively high, greater than 3000 sec$\sp{-1}.$

Notes:

Thesis (Ph.D. in Mechanical Engineering) -- Graduate School of Arts and Sciences, University of Pennsylvania, 1992.

Source: Dissertation Abstracts International, Volume: 53-05, Section: B, page: 2508.

Supervisor: Haim H. Bau.

Local Notes:

School code: 0175.

Access Restriction:

Restricted for use by site license.