Research On Microfluidic Chip Based On Liquid Metal Deformable Electrode And Measurement In Cell Mechanical Properties

The microfluidic chip has the advantages of high efficiency,low cost,and high throughput.It can integrate functions such as separation,analysis,screening,and detection of biological particles on a small chip to complete automated analysis.Therefore,it has broad application prospects in the fields of life science,biomedicine,analytical chemistry,medicine and crop screening.Microelectrodes are a vital part of microfluidic chips,but the microelectrodes in many microfluidic chips use precious metals such as gold and platinum,which are expensive and the shape of the electrodes is fixed and undeformable.The microfluidic chip can only implement a single function.Liquid metal has good electrical conductivity and biocompatibility.In this paper,a flexible deformable microelectrode based on liquid metal is proposed,and the deformation control mechanism and characteristics of liquid metal microelectrode are deeply researched and integrated into microfluidics.In the control chip,the principle of dielectrophoresis is used to measure and analyze the mechanical characteristics of cells,which proves the effectiveness of flexible deformable electrodes based on liquid metal,and solves the limitations of the traditional microelectrode manufacturing process,which is complicated,single-function,and not widely applicable And is expected to apply it to more complex cellular operations.The thesis makes in-depth research on the following four aspectsFirstly,the mechanism research of deformable electrode based on liquid metal was carried out.The flow mechanism and electric capillary principle of liquid metal were deeply explored,and based on these two principles,the flow method and electric capillary method which can control the deformation of liquid metal microelectrodes were developed.These two methods have simple manufacturing processes and controllable electrode deformation.Subsequently,the stability of the electrode was tested,and a method was proposed to enable the liquid metal microelectrode to be stored for a long time.Only the gallium content was changed to change the melting point of the liquid metal.At the same time,it was proved that the liquid metal deformable microelectrode manufactured in this experiment has good physical and chemical stability at normal temperature and remains stable under a voltage of less than 20V.This laid the foundation for the subsequent manipulation of cells with liquid metal electrodes.Secondly,the research on the principle of cell operation based on liquid metal electrodes was carried out.First,the principle of dielectrophoresis is introduced,and its advantages such as label-free,low cost,and high throughput in cell operation are described.Subsequently,the unique advantages of liquid metal are introduced,and the feasibility of constituting the principle of dielectrophoresis based on liquid metal electrodes is mainly studied,and verified by finite element simulation.Subsequently,the mechanism of microelectrodes in cell operation was explored and analyzed,and it was proved that liquid metal can solve the defects of traditional electrodes that are expensive,complicated in process and not widely applicable.Liquid metal electrodes are low cost and recyclable.They are simple to manufacture and can deform the electrode spacing.They have significant advantages in different types and sizes of cell operations,especially in the measurement of cell mechanical properties.The chip laid the foundation for the operation platform.Subsequently,the process research of microfluidic chip and the establishment of experimental platform were carried out.The manufacturing process of microfluidic chip is researched,including male mold manufacturing process,micro-channel inverted mold process,ITO electrode manufacturing process,and liquid metal deformable electrode manufacturing process.The method of morphological control of liquid metal microelectrodes is mainly studied.Different structures of liquid metal deformable electrodes are designed.Different types of liquid metal deformable electrodes can be manufactured according to different application scenarios and combined with microfluidic chips.A cell operation platform based on an integrated liquid metal deformable electrode microfluidic chip was set up,which laid the foundation for the subsequent operation of cells using liquid metal electrodes.Finally,a microfluidic chip with integrated deformable electrodes was used to carry out research in the application of biological cells.Based on a microfluidic chip integrated with a deformable liquid metal electrode and a built operating platform,its application in biological cell manipulation was studied.Liquid metal electrodes have a unique advantage in the measurement and analysis of cell mechanical characteristics by utilizing the characteristics of controllable deformation to adjust the spacing,and have wide applicability to different types and sizes of cells.In this paper,a series of measurement experiments and results analysis were performed on the mechanical properties of mouse venous red blood cells.This experiment proves the applicability of liquid metal deformable electrodes,and also provides new methods and ideas for more complex operations of cells,such as sorting and rotating.