Open Array Microfluidics And Its High-Throughput Applications In Biology And Materials

In the past 30 years,microfluidic technology with miniaturized design has been widely developed and applied in the fields of biology and chemical synthesis analysis.Thanks to the advancement of micromachining technology,the development of microfluidic technology has achieved fast development.Microfluidics is a technology that manipulates fluids in the microliter to picoliter range.Microfluidic chips are usually used and are called "laboratory on a chip" because it can cover the most basic functions of biological and chemical laboratories.Since droplets are suitable for dividing and isolating reactants and have the ability to simulate various conditions similar to micro-reactors,they can transform chemical and biological analysis into a scale and speed that cannot be achieved by conventional laboratory workflows.Therefore,the application of micro-droplets to microbial/chemical experiments has extremely broad research prospects for researchers.However,because traditional droplet microfluidic technology requires the use of complex external equipment,and there are many problems and challenges in the stable formation,storage,and traceability of droplets,many researchers have begun to adopt open microarray technology based on surface tension to respond to various needs in practical applications.Unlike the traditional droplet microfluidic technology,the surrounding oil phase or the physical wall surface in the orifice plate that generates the droplets,the chemically patterned area exhibits the characteristics of a lyophobic boundary,which can prevent the movement and merging of the liquid on the surface.Therefore,without the need for surfactants,droplets with complex geometric shapes and sizes up to a few microns or even nanometers can also be generated on a flat surface.The open array microfluidic technology has great potential in the development of miniaturized platforms for next-generation high-throughput applications due to its easy-to-manufacture platform,high-density array layout,and openness,such as high-throughput screening of live cells and chemical synthesis reactions in an array of droplets on the surface.In this thesis,we focused on the open array microfluidic technology and try to solve some of the problems in the practical application of the technology.Based on the hydrophilic and hydrophobic surface modification technology,we built different open microarray platforms and applied them in biological analysis and chemical synthesis.First of all,this paper proposed a method of forming a concentration gradient array based on open array microfluidic technology.Compared with the traditional droplet microfluidic chip,it does not require complicated external equipment and devices.It only needs a sliding device and a home-made sandwich-structured sliding head to form a concentration gradient array on the microplate chip by sliding method.By controlling the humidity of the environment during the coating process,the evaporation of the solution in the micropores can be suppressed.This platform can be used for the cultivation of lung cancer cells,and the self-made container can reduce the loss of cell culture fluid during the cell culture process.By forming a drug concentration gradient on the cell array,it is possible to study the survival and apoptosis of cells under the action of the drug concentration gradient.The open features of this platform provide opportunities for multi-step operations in the experimental process,and to a certain extent,provide more expandable space for the application of the platform in biological analysis.Secondly,this paper established a multi-layer alignable open array microfluidic platform for the synthesis and in-situ characterization of materials.Aiming at the chemical synthesis process of Prussian blue compounds,and for the characteristics of multiple reactants participating in the co-precipitation reaction,a positioning base was designed for the alignment and reaction between the multiple reactant solution microarrays,and the hydrophilic patterned silicon wafer was placed on the bottom to load the precipitated sample,which is convenient for subsequent in-situ post-processing and characterization of the sample.Through in-situ scanning electron microscopy and X-ray diffraction characterization of samples obtained under different environmental conditions and different reactant concentrations,it is possible to study the effect of different reaction conditions on the morphology,size distribution and crystal phase of Prussian blue compounds.It has certain reference value and significance for the high-throughput screening of the synthesis conditions of materials.Finally,this paper developed a method for high-throughput preparation of all-inorganic perovskite nanorod single crystal arrays with controllable morphology and size distribution on an open array microfluidic platform,and applied it to generation of all-photonic cryptographic primitives and encrypted communication.A solvent atmosphere-assisted recrystallization method was adopted to controll the evaporation environment conditions of the precursor solution droplets,the nucleation and growth of the crystal proceeded slowly,thereby optimizing the morphology of the single crystal.This has important research significance for the synthesis of all-inorganic perovskite micro-droplets on the surface.With the help of the size dispersion characteristics of the single crystal array,combined with the size-dependent laser emission behavior of the perovskite single crystal,such a single crystal array can be regarded as a natural physical unclonable function.Under the premise of formulating corresponding coding rules,the laser emission information of the single crystal array can be collected through laser scanning,and the single crystal array can be converted into cryptographic primitives for encrypted communication.In summary,this thesis has built three different open microarray platforms in response to some problems and needs encountered in the practical application of open array microfluidic technology,and realized the high-throughput preparation of open concentration gradient arrays.We have applied it to the high-throughput drug screening of cancer cells and the high-throughput synthesis and in-situ characterization of Prussian blue compounds.The all-inorganic perovskite nanorod single crystal array was also prepared and applied to the generation of all-photonic cryptographic primitives.