Thesis
Investigating the micro-vortex effects on microfluidic label-free techniques for circulating tumor cell separation
Washington State University
Master of Science (MS), Washington State University
2018
Handle:
https://hdl.handle.net/2376/100914
Abstract
Regarding the serious consequences in terms of human suffering, cancer is recognized as a major health concern worldwide. Cancer metastasis, which defines as the migration of malignant cells from original sites to distant organs, is the main reason of death due to cancer and there is growing evidence that Circulating Tumor Cells (CTCs) are responsible for initiating the metastasis. Therefore, CTCs' detection and separation is of great importance in early cancer diagnostics and treatment. Recently, there has been a growing interest to study and separate CTCs utilizing microfluidic techniques. Due to the presence of external fields (such as electrical) for achieving higher selectivity or applying high Re flow for achieving higher device throughputs in microfluidic devices, the emergence of micro-vortex is inevitable and there is a high demand for fundamental understandings of the vortices' effects on device performance. In this study, mathematical models were employed to investigate the effects of micro vortex on two CTC separation techniques. First, we investigate, Dielectrophoresis as a label-free microfluidic technique to separate CTCs from white blood cells. Due to the presence of external electrical field and temperature gradient, so-called Electrothermal vortices are created inside device and affect the device performance. By developing robust numerical model, we provide design guidelines on choosing appropriate operation parameters such as posts' geometry and electric field characteristics considering the effects of Electrothermal microvortices. In second part of the thesis, we studied Deterministic Lateral Displacement (DLD) as passive microfluidic technique for CTC separation. In order to achieve practical device throughput, higher fluid flow rates should be used in such devices which leads to the formation of vortices. It was found that due to the development of the vortices, the device critical diameter would deviate from previous theoretical predictions. Employing mathematical models, device performance was investigated and new formula was proposed to predict critical diameter in presence of microvortices. Finally, due to high shear rates, cells show a complex dynamic within DLD device and their deformation become significant. It was shown that post geometry would affect cell deformation which results in different trajectories for the cells in those devices.
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Details
- Title
- Investigating the micro-vortex effects on microfluidic label-free techniques for circulating tumor cell separation
- Creators
- Arian Aghilinejad
- Contributors
- Chen Xiaolin (Degree Supervisor)
- Awarding Institution
- Washington State University
- Academic Unit
- Electrical Engineering and Computer Science, School of
- Theses and Dissertations
- Master of Science (MS), Washington State University
- Publisher
- Washington State University; [Pullman, Washington] :
- Identifiers
- 99900525389901842
- Language
- English
- Resource Type
- Thesis