Research On Dielectrophoretic Single-cell Patterning And Control Chip Enhanced By Fluid

The study and characterization about properties of cell biochemistry and biophysics in single-cell resolution can effectively reveal the heterogeneities of its structure function and status of individual cell.And it has played a significant role for deeply understanding the metabolism of different cell,the pathological features of cell-based diseases,the interaction between cells and cell-media.As a promising tool,the single-cell patterning and control has attracted more and more interest.However,most of the recent techniques of single-cell patterning and control are turned out to be high cost and low efficiency.Of course,the popularization and application have been hindered strongly.This dissertation designed a sandwiched dielectrophoretic single-cell patterning and control chip enhanced by fluid via combining non-invasive,label-free,easy-control merits of dielectrophoresis with high-efficiency,low-cost of hydrodynamics.After conducting a series of simulations,optimizations,fabrication crafts and experiments,the high-throughput single-cell patterning and control were realized.The main research contents included are as follows:Firstly,the basic theories of dielectrophoresis,insulator-based dielectrophoresis and hydrodynamics were analyzed.The formula of dielectrophoretic force and factors which will influence the results,micro-wall's influences on spatial non-uniform electric field distribution and micro-wall's influences on laminar flow were obtained.Then the equivalent multilayered spherical shell model of cell was established.The principle of dielectrophoretic trap and release enhanced by fluid was obtained via illustrating the force analysis of cell.Finally,the influence on DEP response of cell of different media conductivity and permittivity was summarized through calculating the frequency response characteristics of OCI cell.Both of these analysis laid theoretical foundation for single-cell patterning and control.Secondly,the structure of sandwiched dielectrophoretic single-cell patterning and control chip enhanced by fluid chip was established by using AutoCAD and Solidworks software according to the above theory of DEP and hydrodynamics.And two working mode were proposed.Then the distributions of electric field and fluidic field were simulated utilizing finite element simulation software COMSOL Multiphysics.Moreover,the optimum structural sizes were confirmed after simulating the influence of different structural size.Thirdly,according to the principles of material selection of microfluidic chip,the materials and fabrication crafts of every part were determined.And the upper and bottom ITO micro electrodes and the SU-8 micro-wall were fabricated utilizing photoetching technology.The PDMS microfluidic channel and pipe joint were fabricated by spin coating.Furthermore,the chip was capsulated via utilizing oxygen plasma bonding technology.Finally,an experimental system for conducting and testing microfluidic chip was established and a PCB pinboard which can connect the chip and functional generator was designed and produced.The frequency and amplitude of the AC signal which made OCI cell generate DEP responses were optimized through using interdigital electrode and the cultured OCI-AML3 cell.After fluorescence staining and handling the OCI cell,the patterned trap and selective release of single-OCI cell were realized in the fabricated dielectrophoretic chip enhanced by fluid.And the efficiency of single-cell trap was above 95%.