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Title: Apparatus and method for concentrating and filtering particles suspended in a fluid

Patent ·
OSTI ID:963815

Disclosed is a device for separating and concentrating particles suspended in a fluid stream by using dielectrophoresis (DEP) to trap and/or deflect those particles as they migrate through a fluid channel. The method uses fluid channels designed to constrain a liquid flowing through it to uniform electrokinetic flow velocities. This behavior is achieved by connecting deep and shallow sections of channels, with the channel depth varying abruptly along an interface. By careful design of abrupt changes in specific permeability at the interface, an abrupt and spatially uniform change in electrokinetic force can be selected. Because these abrupt interfaces also cause a sharp gradient in applied electric fields, a DEP force also can be established along the interface. Depending on the complex conductivity of the suspended particles and the immersion liquid, the DEP force can controllably complement or oppose the local electrokinetic force transporting the fluid through the channel allowing for manipulation of particles suspended in the transporting liquid.

Research Organization:
Sandia National Lab. (SNL-CA), Livermore, CA (United States)
Sponsoring Organization:
USDOE
DOE Contract Number:
AC04-94AL85000
Assignee:
Sandia Corporation (Livermore, CA)
Patent Number(s):
7,534,334
Application Number:
10/956,446
OSTI ID:
963815
Country of Publication:
United States
Language:
English

References (10)

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Electrodeless dielectrophoresis for micro total analysis systems journal November 2003
Low-dispersion electrokinetic flows for expanded separation channels in microfluidic systems: journal February 2004
Insulator-based dielectrophoresis for the selective concentration and separation of live bacteria in water journal June 2004