Research On Continuous Cells Manipulation And Separation Chip Using Dielectrophoresis

There is an important practical significance for rapid separation and purification of biological micro-particles in the fields such as medical diagnostics, biochemical analysis and water quality monitoring. Nowadays, the common techniques of separation include centrifugation, chromatography, flow cytometry, dielectrophoresis separation technology. Microfluidic chip using dielectrophoresis technology become an important methods to manipulate and separate particles due to its advantages such as low consumption, easy integration, low cost, rapid separation. It also has important practical value in the separation, purification and analysis of biological cells.In this thesis, based on the investigation of dielectrophoresis chip at domestic and overseas, the construct of separation chip was designed. Electric distribution and cells trajectory were simulated by COMSOL software. The separation efficiency of living/dead red blood cells was enhanced by optimizing the chip.Firstly, this thesis analyzes the force process of the spherical particles in non-uniform electric field. The mathematical expression of dielectrophoretic force and traveling wave dielectrophoresis force were derived. The relationshipbetween Re(K) 、 Im(K) of living/dead cells and frequency were copulated by Matlab. The chip electrode structure and shape were simulated by COMSOL.And the electric field distribution and the trajectory of particles in microfluidic channels were simulated. The optimized structure of the separation chip was obtained finally.Secondly, the chip materials, including substrate and microfluidic, were selected, glass was selected as the substrate while PDMS selected as the microfluidic material. The fabrication processing of microfludic and electrode array, the usage of reagents/materials and equipment, and the relevant parameters were described in chapter 4.Finally, this thesis designs a control circuit of separation region. The experimental test system was set up. Dielectrophoresis separation chip was used to manipulate and separate the living/dead cells. The results show the living/dead RBCs(Red blood cells) can separated efficiently. This chip provides a new design of thought for combination the dielectrophoresis and the traveling wave dielectrophoresis, which has a great value in further research.