Hi Hengzi,
There are mainly three types of EK flows: electro-phoresis (EP),
electro-osmosis (EO) and di-electrophoresis (DEP) which can occur in
combinations as well. Depending on the application - each of them may be
good or bad compared to pressure driven flows. For proteins in general -
electric fields cause chemical degradation and are not usually suitable
for flow actuation. Preferential surface adsorption of proteins on
microchannels may also give rise to parasitic electro-osmotic flows. For
genomics applications, EP is used with parasitic EO being a problem.
Some methods use EO to enhance EP separation. DEP is used for neutral
particles - such as cells and large polymer chains. However, EO and EP
effects can creep into DEP flows as well. Also, bubbles may form due to
electrolysis. In a simple pressure driven flow - these complications are
not there (though bubble formation remains a problem).
Debjyoti Banerjee, Ph.D.
Microfluidics Engineer
NanoInk, Inc.
215 E. Hacienda Avenue
Campbell, CA 95008.
Ph: (408) 379-9069 x202
Fax: (408) 370-9072
Email: [email protected]
www.nanoink-inc.com
-----Original Message-----
From: [email protected]
[mailto:[email protected]] On Behalf Of hengzi wang
Sent: Wednesday, March 26, 2003 6:41 PM
To: [email protected]
Subject: [mems-talk] What are the disadvantages of EK flow?
Dear folks,
Compared to pressure driven flows, what are the disadvantages of
electrokinetically driven flows, particularly for transporting aqueous
solutions with bio-materials?
Kind Regards,
Hengzi
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