Kanagasabapathi T.T., Backhouse C.J., Kaler K.V.I.S.
University of Calgary, CA
Keywords: continuous fractionation, dielectrophoresis, microfabrication, microfluidics, PDMS
Dielectrophoresis (DEP) [1] The behavior of polarized, neutral particles to the non-uniform electric field has been successfully applied for the levitation and subsequent isolation of biological cells and other micron-sized inorganic particles [2, 3]. This technique has been proven to be reliable and sensitive for noninvasive manipulation of micro and nanoscale particles [4, 5]. The aim of this work is to miniaturize the previously demonstrated work on levitation of microscopic particle under laminar flow conditions to a microchannel assembly made of inexpensive Poly(dimethylsiloxane) elastomer as shown in figure 2 and 3. In this paper, the continuous fractionation of microparticles on the PDMS microfluidic channel is presented. The design, development and fabrication of this microfluidic assembly [6, 7, 8] with an in-built interdigitated microelectrode array is described in detail as shown in figure 1. Preliminary results obtained using microscopic sized (5micrometer) Polystyrene beads prove the levitation phenomena in PDMS microchannel [figure-4]. The polystyrene beads are shown levitated, under negative DEP conditions, above the chamber floor. These levitated beads appear blurred in fig. 4 and they are found to form a pearl-chain. These suspended beads are then separated by fluid flow resulting in a continuous fractionation of the sample. The application of this low-cost, non-invasive technique for isolating a mixture of cancerous cells will be presented. Further integration of this technology with on-chip imaging and control unit will provide a microsystem capable of quantitative and sensitive analysis of the DEP signatures of various cancerous cells.
Journal: TechConnect Briefs
Volume: 1, Technical Proceedings of the 2004 NSTI Nanotechnology Conference and Trade Show, Volume 1
Published: March 7, 2004
Pages: 81 - 84
Industry sector: Medical & Biotech
Topics: Biomaterials, Materials Characterization & Imaging
ISBN: 0-9728422-7-6