| Faraday waves(FWs)bioassembly technology is an emerging type of acoustic bioassembly technology.Faraday wave bioassembly technology has its unique characteristics compared with bulk acoustic wave(BAW)bioassembly technology and surface acoustic wave(SAW)bioassembly technology.(ⅰ)Faraday wave acoustic bioassembly technology has more assembly objects types,which can not only bioassemble the particles floating on the air-liquid interface but also the particles deposited at the bottom of the assembly chamber.(ⅱ)Faraday wave acoustic bioassembly technology has more assembly styles.In the process of Faraday wave bioassembly,the potential energy field with a specific distribution on the liquid surface or bottom is determined by its frequency and boundary conditions.Therefore,the wide frequency range and varied boundary conditions determine the diversity of assembly styles.(ⅲ)Faraday wave acoustic biological assembly technology has excellent biological compatibility.Faraday wave biological assembly works in a low-frequency range with lower acoustic radiation force and sound power.It relies on the hydraulic drag force that mediated to achieve cell manipulation and has less impact on the cell.All the above advantages show the unique advantages and potential application value of the Faraday wave,so it is of great significance to conduct in-depth research on Faraday wave and further develop its application value.Previous studies on the Faraday wave mainly elucidated the principle and application of the Faraday wave in the gas-liquid interface and the application of Faraday wave in the liquid bottom.In addition,previous Faraday wave studies were limited to one cell type and did not assemble multiple heterogeneous cell types.Therefore,in order to conduct in-depth research on Faraday wave and further develop its application value,the influencing parameters and principle of bioassembly in the liquid bottom should be further discussed,and the assembly characteristics of Faraday wave bioassembly of various heterogeneous cell types should be studied.In this thesis,the experimental platform of the Faraday wave bioassembly is established and the experimental equipment and experimental effect are preliminarily verified and characterized.The Faraday wave assembly experimental platform was built and the experimental parameters were measured by means of the series of instruments such as arbitrary waveform/function generator,audio power amplifier,and vibration exciter,so as to verify whether the experimental instrument has high repeatability,accuracy,controllability,and good stability.Then,the experimental parameters of the Faraday wave bioassembly experiment were studied and characterized systematically,including the driving parameters of Faraday wave,the boundary conditions of the assembly chamber,the concentration of particles and the properties of the liquid in the assembly chamber.The driving parameters of the Faraday wave include output frequency and amplitude.The relationship between the Faraday wave frequency and the pattern and the optimum amplitude of the Faraday wave was studied.The boundary conditions of the assembly chamber include feature size and height.Through experiments,it was clear that the assembly chamber of the same shape with different feature sizes can form the same pattern.The larger the feature size,the lower the excitation frequency of the pattern.In addition,the optimum assembly chamber height in the Faraday wave experiment was studied.Then the optimum particle concentration and the optimum hydrogel system in the Faraday wave experiment were studied.Afterward,the assembly effect of particles with different physical characteristics in the Faraday wave was studied and characterized.The structures formed by the assembly or co-assembly of microparticles with different mass densities and characteristic sizes were analyzed qualitatively or quantitatively.It was clear that:(ⅰ)The microparticles with higher density were more concentrated at the center of the node,while the microparticles with lower density were more concentrated at both sides of the node when microparticles of different densities were differential co-assembly by Faraday wave mediated hydraulic drag force.It caused two kinds of microparticles with different mass densities were differential co-assembly at different positions of the nodes at the same time,forming a "package structure".(ⅱ)The microparticles with the size of less than 200 μm were concentrated at the node,while the microparticles with the size of more than 500 μm were concentrated at the antinode when microparticles of different sizes were differential co-assembly by Faraday wave mediated hydraulic drag force.It caused two kinds of microparticles with different sizes were differential co-assembly at nodes or antinodes at the same time,forming a "complementary structure".Finally,we demonstrated the bioassembly effect of Faraday wave on cell microspheres with different characteristic sizes by using cell microspheres instead of microparticles as the research object,and preliminarily verified and characterized it.The experimental results of Faraday wave acoustic bioassembly of cell microspheres are consistent with the results of microparticle assembly,that is,the microparticles with the size of less than 200 μm were assembled at nodes under the action of Faraday wave mediated hydraulic drag force.The microparticles with the size of more than 500 μm were assembled at the antinode and form a "complementary structure" with the microparticles at the node under the action of Faraday wave mediated hydraulic drag.Furthermore,the assembly chamber and hydrogel system in cell assembly were further optimized to make it more suitable for Faraday acoustic bioassembly experiment. |
