Study Of "Acoustic Tweezer" System For The Biological Particles Sorting

Surface Acoustic Wave(SAW)is one of the acoustic waves that travel parallel to the surface of an elastic material,which is capable of manipulating microparticles to move towards a specific direction or form a designed pattern.This SAW device was named acoustic tweezers.Acoustic tweezers possess several advantages,including energy-efficiency,small size and easy-to-produce,enabling separation and manipulation of micron-and even nano-sized particles(i.e.cells,bacteria and viruses).Thus,acoustic tweezers hold great potential in biomedical and clinical field.According to related literature,several acoustic tweezers were designed and applied in the cell separation.However,there are some obstacles which limit the application of acoustic tweezers.Moreover,few has been reported about acoustic tweezers in our country.In this thesis,we introduced the structure classification of acoustic tweezers,designed and developed an acoustic tweezers which can effectively sort micron-sized particles.First,we designed a novel structure of acoustic tweezers chip and optimize the substrate material.Then the size parameters of interdigital transducer(IDT)were optimized and a suitable polydimethylsiloxane(PDMS)microchannel was designed and fabricated.The COMSOL was used to simulate the flow line of the outlet of the microchannel so as to optimize the design and choose a reasonable structure.Finally,the relationship between particle sorting efficiency and flow rate was studied by particle sorting experiment in order to improve the sorting efficiency.The experiment shows that in the case of flow rate 0.11cm/s,the sorting efficiency is highest for the particles of 5 um,and it can reach about 80%.The sorting of the circulating tumor cells in clinical sample using the designed acoustic tweezers will be further studied,which is expected to be applied in the early diagnosis and prognosis of cancer.