(535e) Dielectrophoretic Manipulation of Microorganisms in An Array of Insulators: Theoretical and Experimental Results

The significant advance in microfabrication technology in the past two decades allowed the development of the so called Micro-Electro-Mechanical Systems (MEMS); and these in turn set the basis for miniaturization of analytical devices with biological applications (BioMEMS). BioMEMS are being studied for diverse applications such as medical diagnose and biological assays due to the advantages that come with working in the microscale: shorter separation times, lower production costs, higher performance and smaller required quantities of samples and reagents. Dielectrophoresis (DEP) has been proved as an efficient separation technique with a great potential for miniaturization. DEP is defined as the motion of dielectric particles due to a force exerted on them originated by the presence of a nonuniform electric field. Traditionally, DEP has been carried out employing arrays of electrodes and alternate current (AC) electric fields. Electrode-based DEP allows obtaining high electric field gradients with low applied voltages. This approach may present significant electrolysis and the elevated production cost restricted their massive parallel implementation. An alternative of this electrodes approach is the implementation of an array of insulating structures to achieve the nonuniform electric fields with two electrodes that straddle the array of structures. This approach is known as insulator-based dielectrophoresis (iDEP). In the present work, the manipulation and separation of viable and non-viable cells achieved, by employing a microdevice for iDEP. A computational model is employed to predict the effect of DEP on this bioparticles; the model consists on the implementation of Finite element analysis on a geometry which consists of an array of insulating circular posts distributed along a microchannel. Successful manipulation and separation of viable and non-viable S. cerevisiae was evaluated experimentally employing DC electric fields inside a microdevice containing an array of insulating structures. The results from simulation and experiment were compared.