Fabrication Of Functional Micro-nano Structures Via Printing Strategy

Micro-nano manufacturing technology is the key of transforming functional materials into corresponding functional devices,and is of great significance to the development of functional devices.In the traditional micro-fabrication methods,such as lithography based techniques and3D printing technology,which have been widely used,have shortcomings such as limited materials suitability and accuracy,and have the problems of high energy consumption and high pollution.Various new technologies developed based on self-assembly technology still face challenges in high-precision,multi-dimensional,and large-area structures.In this dissertation,from the perspective of template design,a strategy for the fabrication of precise micro-nano structures and fine interfaces based on the manipulation and patterning assembly of droplet containing functional materials is proposed.Based on the combination of the rigid silicon column template and the flexible polymer template,the controllable preparation of micro-sized Newton's rings and a concave of polymer was prepared.Furthermore,the template of Newton's rings was used to prepare a series of perovskite crystals and the template of meniscus was used to fabricate silver grid(Ag GR)of different resolution.The main research work of this paper is as follows:(1)Preparation of"Rigid and Flexible"micro template.The polymer solution is coated on the micro-scale silicon column template array by spin coating,and a series of factors such as rotation speed,column diameter,polymer rheology,etc.are adjusted to realize the controllable preparation of the Newton's ring pattern.Simultaneously,the results were simulated and deduced to obtain the relationship between the speed of the homogenizer and the height of the spherical crown microstructure.The controllable preparation of the height of polymer concave surface between the silicon pillars was realized by adjusting the polymer rheology.(2)Printed perovskite crystals with colorful ring patterns.The"rigid and flexible"micro template is used to realize the controllable preparation of perovskite crystals,which have the optical structure of Newton's ring.The preparation of perovskite crystals of different sizes is achieved by controlling the types of polymer coatings and assembly conditions.The perovskite crystal possesses the optical structure of Newton's ring,and its change in height also shows that it is a complete replica of the template.Perovskite crystals of different sizes can be applied to different devices such as organic light-emitting semiconductors,solar cells,and so on.(3)Polymer assisted template printing Ag GR with nanometer-level resolution.The plasticity of the polymer is used to design the evaporation difference area,the liquid bridge shrinkage process is controlled,and the Ag GR is prepared by printing in one step.By constructing a meniscus between the silicon pillars,the liquid film has a Laplace pressure difference at the meniscus,and the top area of the pillars is the pinning point,so that the solution containing the functional material will evaporate with the solvent.The substrate shrinks to form a two-dimensional grid pattern.Using this method,silver nanoparticles(Ag NP),fluorescent polystyrene(PS)microspheres and other materials have been successfully assembled.Among them,the transparent electrode made of Ag NP has the highest transparency of 93.10%and the lowest square resistance of 1.656?·sq^-1.