Research On Microfluid Mixing And Particles Manipulation With Microbubble Chip

Microbubbles play an important role in the life sciences,from clinical contrastenhanced ultrasound,ultrasound delivery to ultrasound stimulation therapy,ultrasound thrombolysis,from particle manipulation,microbubble jet to drive,sonoluminescence,and intensive study in various fields has constantly given new vitality to the microbubbles.As a power source,microbubbles can realize non-contact,highefficiency,low-cost and low-energy mixed microfluidics,as well as the manipulation of particles,cells and other substances in the microfluidic channel.Based on the advantages of microbubbles,microbubble chip that can be used to achieve microfluidic mixing and particle manipulation are designed and prepared.The main work and results of this paper are as follows:(1)This thesis presents two schemes for the design of microbubble chip based on previous work,such as acoustothermal cavitation and micro-structure capture.Based on the Rayleigh-Plesset equation,put forward a passive cavitation detection method,which is used to determine the steady-state cavitation of microbubble,the resonance frequency of microbubbles is calculated and analyzes the acoustic radiation force and Stokes drag force in the micro-flow field induced by oscillation microbubbles.Thus the motion state of the particles in the flow field is predicted.Through COMSOL simulation,it is proved that the microstreaming field caused by microbubble oscillation can realize the particle manipulation.(2)The substrate materials of the chip were selected based on two schemes for producing microbubbles,the chip micro/nano processing technology of the two schemes was studied,then,the chip was packaged.The performance of the microbubble chip is tested with the Vector Network Analyzer,infrared thermal imager and optical microscope,The design scheme of microstructure capture microbubble is selected,which has the advantages of low manufacturing cost and high efficiency.By constructing a passive cavitation detection system to detect the state of the work state of the microbubble chip,the uniformity of the acoustic field distribution at the position of the microbubbles in the chip was verified by the laser doppler vibrometer.(3)The Y-type microfluidic channel was designed.The oscillation microbubbles were used as the power source.The relative mixing index was introduced to evaluate the liquid mixing effect.The mixing effect of the liquid under different energies was explored,so as to determine the optimal mixing parameters and the mixing process is ultrafast,the mixing uniformity can be achieved to be 92.7% within 37.5 ms.(4)The microflow pattern induced by oscillation microbubbles was observed by using 2 ?m polystyrene particles as a marker.The oscillation microbubbles can capture the bEnd.3.The microbubble array structure was designed to study the effect of microbubbles of different diameters on particles of different diameters.Polystyrene particles with diameters of 1 ?m and 10 ?m were captured at different diameters of microbubbles.In this thesis,microbubble chip for microfluid mixing and particle manipulation were prepared.The multi-dimensional test was used to verify the superiority of microbubble performance,which provided a research idea for realizing low-cost medical diagnosis in the life science field in the future.