Research On Droplet Transport Method Of Digital Microfluidic Chip Based On Screen Printing

In recent years,microfluidic chips have been widely used in biochemical analysis,clinical diagnosis,food safety and environmental detection.However,the continuous flow microfluidic chip based on the flow channel is complicated in processing,high in production cost,and requires a large number of external equipment(such as pumps,syringes,valves,etc.),which is not conducive to the large-scale application of microfluidic chip.In addition,continuous flow microfluidic chips have a large consumption of samples and reagents,which is not conducive to reducing research costs,especially in the development of some precious reagents.Digital microfluidic chips(DMF)are attracting more and more attention because picoliter-microliter-sized sample reagents in DMF can be accurately and automatically manipulated.In this paper,a fabrication method of digital microfluidic chip based on screen printing technology is presented,and the droplet transport method in digital microfluidic chip is studied.The main contents of this paper are as follows:(1)The preparation technology of conductive carbon ink electrode based on screen printing was studied.The specific processing steps of conductive carbon ink electrode based on screen printing technology were explored,and the effects of mesh number and printing times on the quality of printing electrode were studied.(2)The processing method of digital microfluidic chip was studied.The materials of substrate,electrode,dielectric layer and hydrophobic layer of digital microfluidic chip were selected respectively,and the specific processing methods of each part of digital microfluidic chip and how to assemble each part together were studied.(3)The construction of digital microfluidic system was studied.The power module and control module are designed and assembled respectively,and then the power module,control module and digital microfluidic chip are built into digital microfluidic device.(4)The droplet motion of digital microfluidic chip was studied.By applying different electrified time series to the electrode array,the paper study how to realize the droplet movement,merging and oscillating operation in the open digital microfluidic chip and the distribution,separation,moving and merging operation in the closed digital microfluidic chip.