TITLE

Characterization of electrokinetic mobility of microparticles in order to improve dielectrophoretic concentration

AUTHOR(S)
Martínez-López, José I.; Moncada-Hernández, Héctor; Baylon-Cardiel, Javier L.; Martínez-Chapa, Sergio O.; Rito-Palomares, Marco; Lapizco-Encinas, Blanca H.
PUB. DATE
May 2009
SOURCE
Analytical & Bioanalytical Chemistry;May2009, Vol. 394 Issue 1, p293
SOURCE TYPE
Academic Journal
DOC. TYPE
Article
ABSTRACT
Insulator-based dielectrophoresis (iDEP), an efficient technique with great potential for miniaturization, has been successfully applied for the manipulation of a wide variety of bioparticles. When iDEP is applied employing direct current (DC) electric fields, other electrokinetic transport mechanisms are present: electrophoresis and electroosmotic flow. In order to concentrate particles, iDEP has to overcome electrokinetics. This study presents the characterization of electrokinetic flow under the operating conditions employed with iDEP; in order to identify the optimal conditions for particle concentration employing DC-iDEP, microparticle image velocimetry (μPIV) was employed to measure the velocity of 1-μm-diameter inert polystyrene particles suspended inside a microchannel made from glass. Experiments were carried out by varying the properties of the suspending medium (conductivity from 25 to 100 μS/cm and pH from 6 to 9) and the strength of the applied electric field (50–300 V/cm); the velocities values obtained ranged from 100 to 700 μm/s. These showed that higher conductivity and lower pH values for the suspending medium produced the lowest electrokinetic flow, improving iDEP concentration of particles, which decreases voltage requirements. These ideal conditions for iDEP trapping (pH = 6 and σm = 100 μS/cm) were tested experimentally and with the aid of mathematical modeling. The μPIV measurements allowed obtaining values for the electrokinetic mobilities of the particles and the zeta potential of the glass surface; these values were used with a mathematical model built with COMSOL Multiphysics software in order to predict the dielectrophoretic and electrokinetic forces exerted on the particles; the modeling results confirmed the μPIV findings. Experiments with iDEP were carried out employing the same microparticles and a glass microchannel that contained an array of cylindrical insulating structures. By applying DC electric fields across the insulating structures array, it was seen that the dielectrophoretic trapping was improved when the electrokinetic force was the lowest; as predicted by μPIV measurements and the mathematical model. The results of this study provide guidelines for the selection of optimal operating conditions for improving insulator-based dielectrophoretic separations and have the potential to be extended to bioparticle applications. [Figure not available: see fulltext.]
ACCESSION #
37371691

 

Related Articles

  • Effect of processing fluid and initial concentration on electrokinetic removal of environmental hormone–nonylphenol (NP) from soil matrix. Chung-Hsuang Hung; Ching Yuan; Kun-Cho Chen // Journal of Applied Electrochemistry;Jun2010, Vol. 40 Issue 6, p1123 

    This study was aimed to investigate the electrokinetic removal of environmental hormone––nonylphenol (NP)––from soil matrix under potential gradient of 1 V cm−1 for 5-day treatment. The EK experiments were conducted with four processing fluids of de-ionized...

  • A macroion electrokinetics algorithm. Fixman, Marshall // Journal of Chemical Physics;6/7/2006, Vol. 124 Issue 21, p214506 

    A numerical algorithm is presented for the standard model of macroion electrokinetics and certain generalizations of it. The macroion consists of a cylindrical section with identical, hemispheroidal endcaps, each piece having arbitrary length. The system of one macroion and adjoining salt...

  • Electrokinetic energy conversion efficiency in ion-selective nanopores. Chih-Chang Chang; Ruey-Jen Yang // Applied Physics Letters;8/22/2011, Vol. 99 Issue 8, p083102 

    Taking hydrodynamic slippage into account, we derived an exact expression for the figure of merit to evaluate the electrokinetic energy conversion efficiency and power of an ion-selective nanopore. In the absence of slip, and when the ratio of the radius and the Gouy-Chapmann length (a/λGC)...

  • Single-molecule mobility and spectral measurements in submicrometer fluidic channels. Stavis, Samuel M.; Edel, Joshua B.; Yougen Li; Samiee, Kevan T.; Dan Luo; Craighead, Harold G. // Journal of Applied Physics;8/15/2005, Vol. 98 Issue 4, p044903 

    Electrophoretic mobility differences of biological molecules are frequently exploited to physically separate and subsequently identify the components of a mixture. We present a method to rapidly identify single molecules by measuring both their mobility and fluorescence emission under continuous...

  • Room-temperature ferromagnetism induced and controlled by electric field in BaNbO3 films. Cao, Ensi; Qin, Hongwei; Zhang, Yongjia; Hu, Jifan // Applied Physics Letters;12/3/2012, Vol. 101 Issue 23, p232407 

    The application of electric field can induce the room-temperature ferromagnetism (FM) in paramagnetic BaNbO3 films on the conductive Nb:SrTiO3 substrate. The electric field-induced ferromagnetism in BaNbO3 is connected with the hybridization between electrons of Nb-4d1 and the injected electrons...

  • Manipulation of a one dimensional molecular assembly of helical superstructures by dielectrophoresis. Kubo, Wakana; Fujikawa, Shigenori // Applied Physics Letters;10/19/2009, Vol. 95 Issue 16, p163110 

    We demonstrate that it is possible to manipulate helical superstructures composed of self-assembled chiral lipids by dielectrophoresis while preserving the shape of the superstructures. Alignment and migration of the helical fibers were only observed for an applied ac field of 1 kHz–1...

  • Programmable Fragrance by Manipulation and Releasing of Essential Oil Droplets on an Electro-Microfluidic Platform. WEI-KAI HUANG; YI-TING LO; SHIH-KANG FAN // International Journal of Transport Phenomena;2015, Vol. 14 Issue 1, p15 

    We present an electro-microfluidic (EMF) platform capable of manipulations of essential oil droplets and releasing of the fragrance. Different essential oil droplets, including orange, rosewood and clove, representing top, middle and base notes of the fragrance, respectively, with the volume of...

  • Flow and species transport control in grooved microchannels using local electrokinetic forces. Hahm, Jungyoon; Balasubramanian, Ashwin; Beskok, Ali // Physics of Fluids;Jan2007, Vol. 19 Issue 1, p013601 

    We present numerical simulation results for flow and species transport control in grooved microchannels using locally applied electric fields, and zeta potential patterned groove surfaces. The resulting mixed electro-osmotic/pressure-driven flow enables entrapment and release of prescribed...

  • Improvement of the load-carrying capacity of offshore skirted foundations by electrokinetics. Micic, S; Shang, J Q; Lo, K Y // Canadian Geotechnical Journal;Oct2003, Vol. 40 Issue 5, p949 

    Originating from the problem facing offshore foundation engineering, the present study is focused on using electrokinetics to enhance the load-carrying capacity of skirted foundations embedded in soft marine deposits. An experimental study was carried out in a model tank having dimensions of 150...

Share

Read the Article

Courtesy of THE LIBRARY OF VIRGINIA

Sorry, but this item is not currently available from your library.

Try another library?
Sign out of this library

Other Topics