Nonlinear electrokinetic transport and its applications under combined AC and DC fields in micro/nanofluidic interface devices

Nandigana, Vishal

Permalink

https://hdl.handle.net/2142/29477 Copy

Description

Title

Nonlinear electrokinetic transport and its applications under combined AC and DC fields in micro/nanofluidic interface devices

Author(s)

Nandigana, Vishal

Issue Date

2012-02-01T00:48:22Z

Director of Research (if dissertation) or Advisor (if thesis)

Aluru, Narayana R.

Department of Study

Mechanical Sci & Engineering

Discipline

Mechanical Engineering

Degree Granting Institution

University of Illinois at Urbana-Champaign

Degree Name

M.S.

Degree Level

Thesis

Keyword(s)

• Concentration Polarization
• Nonlinear Electrokinetic transport
• Micro/Nanofluidic interface devices
• AC/DC electric fields
• Debye length
• space charge
• alternating current (AC)
• direct current (DC)

Abstract

The integration of micro/nanofluidic devices led to many interesting phenomena and one of the most important and complex phenomenon among them is concentration polarization. In this thesis, we provide new physical insights in micro/nanofluidic interface devices on the application of AC and DC electric fields. By performing detailed numerical simulations based on coupled Poisson, Nernst−Planck, and incompressible Navier−Stokes equations, we discuss the electrokinetic transport and other hydrodynamic effects under the application of combined AC and DC electric fields for different nondimensional EDL thickness and nanochannel wall surface charge density. We understand that for a highly ion−selective nanochannel, the application of combined AC/DC electric field, at amplitudes greater than the DC voltage and at low Strouhal number, results in large dual concentration polarization regions (with unequal lengths) at both the micro/nanofluidic interfaces due to large and unequal voltage drops at these junctions. The highly nonlinear potential distribution gives rise to an electric field and body force that changes the electrokinetic fluid velocity from that obtained on the application of only a DC source. With the understanding of nonlinear electrokinetic transport under combined AC/DC fields, we propose a novel technique of increasing the product concentration of an enzymatic reaction inside the nanofluidic channel.

Graduation Semester

2011-12

Permalink

http://hdl.handle.net/2142/29477

Copyright and License Information

Copyright 2011 Vishal Venkata Raghave Nandigana

Owning Collections