Flow Characterization of a Liquid Micromixer Tony Hyun
Flow Characterization of a Liquid Micromixer
Tony Hyun Kim, Troy V. Tamas
6.152J/3.155J Nano/Micro Processing Technology, Spring 2009
Abstract: Measurements of fluid velocity and diffusion coefficient were performed in a channel of a microfluidic
mixer. Both are shown to be in good agreement with theory, with Umax(meas)=1.780.11 mm/s [c.f. Umax(theory)=1.84];
and Dmeas=1.510 cm /s [c.f. Dtheory = 210 cm /s].
A microfluidic device was created in
order to mix the contents of two
reservoirs through a 200um-wide,
30mm-long diffusion channel.
The operation of the micromixer was
visually inspected via an optical
microscope. The flow velocity and the
diffusion coefficients were in good
agreement with predicted values.
Assume laminar flow, for which:
The two fluids mix as they flow down
the channel, showing increase in
diffusion length scale, w.
Q: flow rate
Input reservoirs were loaded with
22.50.7 mm of water.
Microbeads were added to each
The motion of the microbeads in the
channel was filmed using a PC-based
Spin on 50-micron thick SU-8
Develop with PM-acetate and
silanize to discourage
bonding with PDMS.
Pour PDMS on master wafer.
Al rods define the reservoir
Remove PDMS mold.
Velocity was measured by analyzing
snapshots of the fluid flow, as shown
Maximum Fluid Velocity:
Place on glass slide and
bond with ashing. Insert tube
Umax=1.780.11 mm/s (measured)
Actual diffusion was constrained by an
opposite wall. (See below)
restricted diffusion (lower D)
w(t ) 2
4 ln 2
Two reservoirs were filled with water
and fine-tuned to have equal heights.
Red dye was added to one reservoir
to track diffusion
Microfluidic mixer was fabricated.
LEFT: The boundary between
the two fluids was set at the
midpoint of the channel by
adjusting the heights of the two
Flow characterization experiments
were performed, yielding:
RIGHT: Blue intensity profile
across the lateral channel
position, at 200 pixels above
bottom of image.
Image analysis technique:
Theoretical model was based on diffusion into
an infinitely sized sample.
Using Uavg = 2/3*Umax, and the
position along the channel, duration
of diffusion is determined.
ABOVE: By considering two consecutive snapshots of the flow (with
known time difference between them) the velocity of particle flow can be
Pixel values were calibrated by
measuring known feature sizes.
Why is the diffusion coefficient lower than
Prepare master template by
LEFT: Device mask for
the micromixer. The top
two reservoirs are
connected to the
reservoir through a
long, narrow channel.
Differentiate the profile
Measure half-width half-maximum
of differential to obtain the diffusion
length scale, w
Measurements show good
agreement with theory device
behaves as expected.
We would like to thank Scott Poesse for his
guidance in lab; as well as the other students in
our group: Edison, Cankutan, Rebecca and
Contact: [email protected], [email protected]
Oedipus: "It is a dreadful mark of shame I have borne since childhood." (Sophocles 94) Oedipus' swollen ankles and his scar from being pinned at his feet represent a shame that will never go away, a point of weakness for...
Madagascar Hissing Cockroach Life History Female hissing roaches lay their eggs in a purse-like capsule known as an ootheca. This egg case is retained within the body until the eggs hatch, and the young roaches first see the world as...
DIGOXIN (LANOXIN) 7/16/2013. Winter 2013. DIGITALIZATION. The administration of digitalis or one of its glycosides in a dosage schedule designed to produce and then maintain optimal therapeutic concentration. CARDIAC GLYCOSIDES HAVE BEEN USED TO TREAT HEART FAILURE FOR OVER 200...
in TRC Annual Research Forum All FURAP undergraduate participants are required to share their studies and findings through posters or models/products during the TRC Annual Award Conference. Best projects will be recognized and the winning teams will be rewarded.
In addition to computing an overall activity rate for each activity cost pool, an activity rate is computed for each type of overhead cost that is consumed supporting a given activity. ... Unit-Level Activity Batch-Level Activity Product-Level Activity Customer-Level Activity...
The 4th Amendment. The right of the people to be secure in their persons, houses, papers, and effects, against unreasonable searches and seizures, shall not be violated, and no Warrants shall issue, but upon probable cause, supported by Oath or...
Cigna Dental Plan Training PPO plan In network dentists must follow the fee schedule. They cannot balance bill the member Out of network dentists are allowed to balance bill over the allowable charges Discounts apply to all services (very important...
* Greening of economic agencies Evolution of environmental strategies in China (12) * Greening of economic agencies Evolution of environmental strategies in China (13) (Source: Shi, H. and L. Zhang, 2006) * Economic actors step in Search for more affordable...
Ready to download the document? Go ahead and hit continue!