Particle Manipulation Employing Alternating Current Electric Fields in An Array of Insulators

Dielectrophoresis (DEP) is the motion of particles in due to polarization effects in nonuniform electric fields; this electrokinetic transport mechanism has a great potential for the manipulation of a wide array of bioparticles, ranging from biomolecules to microorganisms [1]. DEP can be carried out employing DC and AC electric fields. The majority of the studies on DEP have employed arrays of microelectrodes, however, employing microelectrodes has some drawbacks such as high cost and loss of functionality due to fouling [2,3]. Insulator-based dielectrophoresis (iDEP) is an attractive alternative, since it employs arrays of insulating structures, instead of electrodes, to create nonuniform electric fields; resulting in inexpensive and robust devices [4].

This study presents the manipulation of microparticles employing alternating current electric fields with iDEP. The effect of varying operating conditions, such as suspending medium characteristics, magnitude and frequency of the applied AC fields, over the dielectrophoretic response of the microparticles was analyzed through a mathematical model developed using Finite Element Analysis with COMSOL Multiphysics®. By solving Laplace equation between the cylindrical post array it was possible to predict the regions of higher field intensity and the location of dielectrophoretic traps. It is expected that these findings will be employed as a tool for the design and selection of operating conditions of dielectrophoretic microdevices for bioparticles concentration and manipulation.

References

[1] J. Voldman, Ann. Rev. Biomed. Eng. 8 (2006) 425.

[2] Y. Kang, B. Cetin, Z. Wu, D. Li, Electrochim. Acta 54 (2009) 1715.

[3] Y. Kang, D. Li, S. Kalams, J. Eid, Biomed. Microdev. 10 (2008) 243.

[4] E.B. Cummings, A.K. Singh, Anal. Chem. 75 (2003) 4724.