Dielectrophoresis-Assisted Deterministic Lateral Displacement for Particle and Cell Sorting
thesisposted on 01.11.2017 by Wajid Ali
In order to distinguish essays and pre-prints from academic theses, we have a separate category. These are often much longer text based documents than a paper.
This work presents an experimental proof of concept and preliminary findings for a microfluidic device to separate micro-particles and cancer cells. Deterministic lateral displacement (DLD) and di-electrophoresis (DEP) have been proved as promising tools in cell sorting for circulating tumor cell (CTC) separation. However, both methods have their drawbacks. For example, DLD lacks the ability to separate white blood cells and cancer cells with similar sizes, and DEP separation is often based on trapping mechanism, which suffers from low throughput. In this presentation, we report a microfluidic device based on the combination of DLD and DEP, which is enabled by a novel contactless electrode design. These electrodes help generate a non-uniform electric field around the DLD pillars, which then induces a DEP force to the cells that are passing through the microchannel. The device can perform cell sorting with overlapping sizes and with high throughput at the same time. We studied and characterized the device with both experimental and simulation work. For A549 lung tumor cells with 14-micron size, the device can control its trajectory from bumped mode to zig zag mode. Cell viability testing showed that more than 95% of the cells were viable with 30mins flow rate at 0.5ml/hr at applied voltage of 800V. These results demonstrate our method as a promising tool for label-free CTC separation for cancer diagnosis.