Research On Fluid Multiphysics Simulation And Microwave Test

The technology of microfluidics refers to the popular field of technology that uses tiny channels with geometrical dimensions of a few microns to hundreds of microns to systematically manipulate minute amounts of fluids.The technology was first used in microelectronic chip labs and inkjet print heads,and over time has become a multidisciplinary research field involving molecular biology,microelectronics,clinical medicine,chemistry,and more.Near-field microwave scanning method due to its high sensitivity when scanning,biological detection,food detection and chemical element analysis and detection applications have a high appeal.In particular,the imaging of biological cells and the detection of electromagnetic properties of biological solutions,the accurate determination of protein content and lactose content of foodstuffs already with or without spoilage,and the dielectric spectroscopy testing of liquids in the pharmaceutical and medicine industries.This thesis combines a microfluidic chip and a near-field microwave microscope system to carry out biological solution detection in an advanced experimental environment,and achieves an extension of the scanning range of the near-field microwave microscope system,as well as validates the high spatial resolution and high accuracy in its electromagnetic property testing of biological fluids and solutions.Multi-physics field simulations have been an important tool to explore the physical laws,and in this paper,relevant simulations are carried out for all parts of the experiments,especially for the microfluidic part of the multi-physics field simulations.The multiphysics field simulation of liquid-liquid two-phase flow is carried out first.The multiphysics field simulation of liquid-liquid two-phase flow mainly simulates the combination of different flow velocities of continuous and dispersed phases in the twophase flow,and investigates the conditions that produce different flow patterns when the T-type microfluidic chip does the liquid-liquid two-phase flow test.After that,the electromagnetic field frequency domain simulation of near-field microwave scanning,near-field microwave scanning electromagnetic field frequency domain simulation mainly for liquid,microfluidic chip respectively near-field microwave scanning simulation,to explore the near-field microwave scanning probe tip liquid,microfluidic chip in different conditions of the electromagnetic response of what factors affect.These simulations are analyzed in detail on the results and can be used as a guide for subsequent experiments.A new method for measuring the flow rate of microfluidic chips was subsequently implemented by experimentally using Near-Field Scanning Microwave Microscopy(NSMM)to detect flowing liquids in microfluidics.This method does not depend on the particle heterogeneity in the measured sample medium and can detect the inherent electromagnetic properties of the fluid.Compared to conventional flow measurement methods,the flow rate of the sample under test can be measured using the NSMM system without the use of an invasive detector inside or in contact with the sample,and the original properties of the sample can be preserved.The use of a near-field microwave scanning system to detect flowing fluids has expanded the use of near-field microwave scanning by breaking through the previous status quo of scanning only static samples.In this paper,the droplet generation through the microfluidic chip is doped with a high conductivity material.Simulation of large cell populations flowing within the microfluidic chip,and then through the near-field microwave scanning experiments to derive near-field microwave can detect the electromagnetic response of the sample in the flow results.