Abstract
A technique called dielectrophoresis (DEP) has been proved to be an effective method for the separation of cells, bacteria and other bioparticles. This separation technique is particularly attractive in many areas such as biomedical research, clinical diagnosis, food pathogen detection, rapid drug discovery and environment analysis. Yet, this technique has not been widely adopted for clinical applications due to the complexity of device fabrication. The device has to be fabricated in micro-scale that capable to accommodate micro litre sample volumes. In addition, the wide use of planar microelectrodes in separation devices requires a narrow flow channel to attract particles towards the electrode. This small sample volumes and thin flow channel will end up with low throughput separation. Therefore, a simple high throughput separation device is constructed at low cost and no need of hi-tech facilities. To enhance and improve the throughput, a laminated 3D Dielectrophoretic well (DEP-well) electrode namely DEP-well M-16/M-20, DEP-well C-35 and DEP-well C-0 are proposed. These 3D DEP-well electrodes are different in number of wells, diameter, angle and materials used to fabricate the well. The DEP-well is able to overcome the decrement of DEP force strength over the distance from the planar arrays. As a result, at flow rate of 5ul/min, the DEP-well M-16 was able to trap viable yeast cells at an average of 56. 7%. Then, with a series arrangement of wells using DEP-well M-20, the trapping percentage increased to 75. 7%. The percentage was improved to 80. 5% using a smaller diameter of well (DEP-well C-0). Subsequently, 35 angle of well (DEP-well C-35) was able to capture a slightly greater percentage (about 83. 2%) of viable yeast cells. This shows that, the developed separation device utilising DEP-well electrode is able to offer reasonably high trapping efficiency and produced high throughput separation. It also offers other advantages which are portability, reusable, economical and ease of use as well as easy to assemble.