The Study Of Fabrication Method Of Micro-filter Used In CTCs Enrichment And Detection

Nowadays,with the rapid development of microelectronics and the great attention in the fabrication of micro-and nanostructures,a series of simple,rapid and convenient micro-nanofabrication methods have been developed,such as optical lithography,ebeam lithography,nanoimprint lithography,molecular self-assembly,etc.These methods have wide potential applications in microelectronics,optics,optoelectronics,biology,and so on.All the fabrication methods have their own advantages and disadvantages.Hence,it is quite meaningful to select the suitable method to achieve a rapid and low-cost fabrication process,especially in civil fields.Cancer has been the leading cause of death worldwide.So far,researchers have made significant progress in the treatment of cancer.However,the mortality still remains in a high level due to metastatic tumors.To improve the survival of cancer patients,it is extremely important to establish new feasible diagnostic methods characteristic of not only as accurate predictors for possible formation of metastasis and real-time monitors of antitumor treatment efficacy as well.According to the studies,circulating tumor cell has great significance in assisting malignancy diagnosis,estimating prognosis,and response of the anticancer therapy.However,the current CTC enrichment method usually have some disadvantages,such as high cost,long time consuming,low capture efficiency,etc.Thus,we demonstrated a morphologic-based isolation method via photolithography,lift-off and etch process.We successfully fabricated a wafer-scale parylene micro-filter,which achieved the capture efficiency as high as 84%,much higher than those commercial membrane micro-filter.We also captured CTC from the cancer patient blood sample with this micro-filter,showing a great value in clinical applications.In this study,we also fabricated a wafer-scale nickel mold through the photolithography,deep silicon reactive ion etching and electroplating process.Subsequently,with the nickel mold,we investigated the fabrication of parylene micro-filter through the thermal nanoimprint method in a convenient,rapid and lowcost process.At present,energy crisis is another big problem all around the world.Thus,solar energy has attracted much attention as a renewable energy source.Solar cell,which could convert solar energy into electric energy,is one of the best solutions.However,the photoelectric conversion efficiency is limited by the high reflection to flat Si.There have been a lot of researches about the fabrication of silicon antireflection substrates.Whereas the theories of the mechanism were still not clear.In this study,we designed the experiments to investigate various impacts on silicon antireflection results.We achieved a periodic Ni dot arrays(600 nm period,350 nm diameter)via nanoimprint lithography.We also demonstrated a disordered Ni dot arrays(the diameter ranges from 200 nm to 400 nm)via the phase separation of PS/PEG polymer blends.We fabricated ordered/disordered silicon nanopillars with different height,aspect ratio and morphologies by adjusting the dry etching parameters.The reflectance spectrum were measured of the wavelength from 200 nm to 1000 nm.Thus,we analyzed the effects of height,aspect ratio,degree of structural order and morphologies on silicon antireflection results.