256537 Joule Heating Effects On the Dielectrophoretic Force for iDEP Devices

Tuesday, October 30, 2012: 3:36 PM
Somerset West (Westin )
Roberto Gallo, Cátedra de BioMEMs, Instituto Tecnológico y de Estudios Superiores de Monterrey, Monterrey, Mexico, Rafael Davalos, School of Biomedical Engineering and Sciences, Virginia Polytechnic Institute and State University, Blacksburg, VA and Blanca H. Lapizco-Encinas, PhD, Chemical and Biomedical Engineering, Rochester Institute of Technology, Rochester, NY

Dielectrophoresis (DEP), the movement of particle due to polarization effects in nonuniform electric fields, is a technique that is receiving significant attention for many different applications. Traditionally, DEP has been employed using arrays of microelectrodes, which can have some challenges when handling bioparticles. An alternative is the use of arrays on insulators, instead of electrodes to generate nonuniform electric field. In insulator-based dielectrophoresis (iDEP) an array of insulating structures is straddled by two remote electrodes, the presence of the insulators distorts the distribution of  the local electric field, creating zones of higher and lower field intensity.  Novel designs that apply this principle are being reported continuously since there are still wide areas of opportunities when referring to selectivity and efficiency.  Some of the challenges with iDEP devices is that high potentials are required to achieve effective particle manipulation, leading to the generation of Joule heating in the system. Such phenomenon often produces important temperature increase that directly affects the conductivity of the suspending medium. As a result the local electric field will also be affected. In this work, the temperature effects due to Joule heating by the application of a DC electric potential will be investigated for a channel for iDEP with circular insulating posts. The conductivity, the local electric field, and gradient of the squared electric field important for the magnitude of the dielectrophoretic force were computationally simulated. The temperature increase through the channel decreases the magnitude of the dielectrophoretic force and therefore makes it more difficult to overcome electrokinetics and have a trapping effect on particles.

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