Research On High-pergormance Paper Electronic Manufactyring Technology Based On Electric-field-driven Jet Deposition Micro-nano 3D Printing

As a new product in the field of flexible electronics,paper electronics has the advantages of environmental protection,biodegradability,and low cost.It is widely used in many fields such as biosensors,miniature capacitors,and paper-based tag antennas.However,paper substrates are different from existing hard substrates(silicon wafers,glass,etc.)and flexible substrates(PET,PC,etc.),and have the characteristics of porous structure,high temperature resistance,and no waterproofing.The existing lithography,inkjet printing,screen printing and other technologies to achieve high performance(high resolution,high aspect ratio,etc.)conductive circuit on the surface of paper substrate face great challenges.In response to this problem,a new method for preparing high performance paper electronics was proposed based on the electric-field-driven(EFD)jet deposition micro-scale 3D printing combined with high viscosity and low temperature sintering nano-silver paste.This thesis systematically analyzes and experimentally validates the proposed process from four aspects:theoretical analysis,process optimization experimental research,and structure and electrical properties of different paper based silver wires research and specific case study.The main research work and innovation are as follows:(1)Based on the EFD jet deposition micro-scale 3D printing combined with high viscosity and low temperature sintering nano-silver paste,a new method for manufacturing high-resolution,high-aspect ratio paper circuits is proposed.Combined with the existing theoretical basis,the basic method and process flow of preparing paper-based circuit by this process are elaborated and analyzed in detail,and the principle of EFD 3D printing technology and the preparation of high viscosity and low temperature sintering nano-silver paste are systematically summarized.(2)According to the relevant theoretical analysis,mainly from the specific process parameters on the print results and the influence of sintering process parameters on the electrical properties of the conductive circuit and the influence of the law of the system experiment and research,and optimize the corresponding most appropriate process window.The experimental results show that the printing voltage,printing pressure,printing speed and printing height are the main factors that affect the morphology and properties of silver wire,and sintering temperature and sintering time of printing materials are important factors affecting the electrical properties of conductive circuits.The results show that:(1)If the voltage is too low or too high,the shape of the silver wire will be deteriorated.RC photo paper is suitable for printing voltage 500?800V,coated paper is suitable for printing voltage 800?1400V,copy paper is suitable for printing voltage 800?1000V.(2)The printing speed is negatively correlated with the line width.When the printing speed is too fast,the silver line will be discontinuous.RC photo paper is suitable for printing speed of 20?50mm/s,coated paper is suitable for printing speed of 10?25mm/s,copy paper is suitable for printing speed of 5?10mm/s.(3)The printing pressure determines the extrusion volume of the material and is positively correlated with the printing line width.However,when the printing pressure is too small,the morphology of the silver line will be poor,the excessive pressure causes a lower resolution,and a suitable printing pressure is 120?180k Pa.(4)The width of the printing line decreases with the increase of the printing height,but when the height is too high,the Taylor cone will break the silver line due to external interference,so it is suitable for the printing height of 150?m.(5)With the increase of sintering temperature and sintering time,the electrical properties of the conductive circuit are good,but too high temperature and too long time will destroy the surface structure of the paper substrate,suitable for sintering temperature 80?,sintering time 60min.(3)Using EFD micro-nano 3D printing process and high-viscosity low-temperature sintering nano-silver paste,combined with optimized process parameters,multi-layer stacking on different paper base surfaces to achieve a large aspect ratio micro-nano structure,and get the mathematical model of different paper-based silver wire structure and electrical properties.After 15 layers are deposited on RC photo paper,the aspect ratio can be increased to 6.33;After 15 layers of stacking on the surface of coated paper,the aspect ratio increases to 5.2;After eight layers of stacking on the surface of the copier paper,the aspect ratio increases to 0.79.MATLAB data analysis software was used to fit the structural characteristics of the silver wire mathematical model,and verify its feasibility.It provides a mathematical theoretical model of electrical properties characterization for the subsequent manufacture of EFD micro-nano 3D printing paper electronics.(4)Based on the new method of preparing paper electronics by EFD micro-nano3D printing proposed in this paper,specific application cases are analyzed and researched.Complex conductive patterns of circular,rhombus and pentagonal grids with an area of 5cm×5cm were prepared on the surface of copy paper,coated paper and RC paper,and two functional circuits of lamp array and bookmark lamp were prepared.RFID tag antennas with bending times of 2 and 3 were made on the surface of RC photographic paper and coated paper.Through simulation analysis and actual measurement,the return loss S₁₁=-26.99dB and S₁₁=-30.3dB were obtained,respectively.The test result is basically the same as the simulation result,which is approximately conjugate matching with the electronic chip Andy100 used in the experiment,which meets the impedance matching requirements.Flexible Electromagnetic Actuators(FEMAs)was prepared by multilayer stacking on the surface of copier paper and its performance was characterized.