Methods And Experimental Study Of Laser-guiding Cellular Orientation In Microfluidic Chip

The use of laser force to achieve the fluid cells within the non-contact,no damage,no damage to the drive,has been in the life sciences and biochemistry and other fields have been applied.With the maturation of microfluidic technology,microfluidic chip has been used in cell culture,cell separation,cell analysis,etc.,how to use laser to achieve microfluidic chip channel cell orientation there are many theories,methods and technical problems.Therefore,it is of great theoretical and practical value to study the method and experimental study of cell-oriented microfluidic chip.In this paper,the mechanism of the effect of laser on micro particles in micro channels is studied theoretically.By analyzing the Rayleigh scattering theory,the Mie scattering theory and the generalized Lorenz-Mie theory,the calculation method of the scattering force and the gradient force is given according to the different cell states and sizes.And the centrifugal double-layer model was used to calculate the force of the cells along the beam direction.The numerical simulation and software simulation of the effect of laser on micro particles were carried out by COMSOL Multiphysics software.Through the numerical and software simulation,we get the force calculation of different types of cells in laser radiation and analysis of its movement.On the basis of this,a method of embedding fiber laser into microfluidic chip is proposed to realize the guidance of laser to microfluidic chip and improve the utilization and effective focusing of laser.In the process of experiment,the fabrication process of microfluidic chip and the conduction coupling process of fiber laser are discussed in detail.The schemes and experimental process of embedding several different optical fibers into the chip are described.And finally the laser flow can be directly introduced into the microfluidic chip channel,and the formation of lateral laser on the channel to guide the cells to achieve the microfluidic chip channel within the cell movement trajectory changes.Finally,the best experimental results are given: when the flow rate is 0.3ul/m and 0.1ul/m of the main channel,the hydraulic focusing effect is the best.Using 960 nm,200mw pump laser through the fiber transmission can make the cell trajectory slightly offset.The experimental results show that the theoretical analysis and simulation results are in good agreement with the experimental results.The experimental data confirm the results of the simulation experiment.The paper also gives the shortcomings of the research work and the future improvement direction.The combination of laser technology and microfluidic technology has opened up the development space of traditional optical devices,making it more powerful,more accurate and smaller in size,and also has a new development direction for microfluidic chips.