Abstract
MEMS (Micro Electro Mechanical Systems) have been developed over twenty years. Because of the rapid development of biological technology, there are a lot of applications for MEMS in bio-medical field. The bio-chips developed nowadays include cell sorting\separation chip, cell lysis chip, PCR (Polymer Chain Reaction) chip, DNA detection chip etc. These chips could be integrated into a Lab-On-a-Chip system for full functional disease detection and analysis. This thesis focuses on cell sorting\separation and the design of a new chip in substitution for traditional cell separation process. There are a few MEMS cell separation measurements have been presented, including micro filter, micro hydraulic switch and dielectrophoresis. Therefore, the micro filter has stuffing problem while the hydraulic switch requires extra external real-time detection. Dielectrophoresis has been known as a powerful tool for cell separation because of its good cell selectivity. Presently, the published dielectrophoretic cell sorting methods are limited to separate no more than three cell types due to the single frequency signal. We firstly proposed the concept of multi-frequency dielectrophoresis. With special structure design, we can separate multiple cell types by applying multiple frequencies simultaneously. The thesis starts with the survey of literatures, via theoretical analysis to evaluate the feasibility of design concept and to define the design regulations. Through numerical analysis, the design concepts are verified and realized by MEMS fabrication process. Furthermore, a driving signal generator is also designed and tested. Finally, we use polystyrene beads and glass beads to simulate cells to complete the preliminary experimental results.