Design And Fabrication Of PDMS Microfluidic Chip In A Novel Flow Cytometry

Classification and counting of cells is a means of biomedical testing relies on.In recent years,micro-fluidic chip cell sorting and counting method,with its automatic,accurate and quick advantage quickly gained popularity,research.Among them,the focus is one of the key technologies of micro fluid.This paper designed a new Microfluidic Chips and processing,the chip is able to cells in fluid focus,enable samples to be good classification and counting.In a variety of micro-channel technology,this paper chose the low cost and the difficulty in processing small polydimethyl siloxanes(PDMS)and thin glass bonding method of making micro-fluidic chip with micro-flow control in fluid focus technology to focus the sample of cells,cells of a single row by observing the area when focusing.Microelectronic machining technology of micro-fluidic chip lithography and plasma bonding process.First,using lithography technology and exposure process will AutoCAD by design of micro-flow control channel graphics transfer to wafer surface of SU-8 lithography rubber Shang,through developer formed has must thickness of micro-flow ditch road model;then,using PDMS for pouring,curing stripping Hou in PDMS surface formed micro-flow ditch Road;last,will thin glass tablets and PDMS micro-flow ditch road side through plasma key collection,get micro-flow control chip.Found in the earlier test,only using the traditional method,use a y-shaped channel in fluid focus,the results are unsatisfactory,cells still have the velocity is not stable,and beyond,and so on.To this end,the design of sheath fluid flows with different shapes road,junction with Microfluidic Chip buffer structure,aimed at the Elimination of flow instability.Through simulations and sheath fluid passages on both sides to join the proposed y-focused channel of the bezel,enabling cells to smooth not overtaken by observing the area.Chip testing,change shape,junction of sheath flow passage buffer structure,to some extent,eliminating errors due to mechanical pump junction flow instability.Sheath fluid and sample channels at 30°,45°and 60° angle of the case,experimentally observed a focusing effect,results show that the 60°angle focusing works best.Finally test the sheath fluid-channel Microfluidic Chip with a bezel,with the sheath fluid flow and flow rate of the sample different,focal width is different,when the ratio between them is 3:1,the focus width can be controlled in a cell.