Research On Processoptimizationand Applicationsof Electric-field-drivenjet Deposition Micro-nano 3D Printing Technology

Electric-field-driven jet deposition micro-nano 3D printing is a novel micro-nano 3D printing technology,which shows great advantages and has many applications in different printing materials(conductive,non-conductive),different substrates(hard,flexible).However,the current process parameters window for the large-scale industrial application of electric-field-driven jet deposition micro-nano 3D printing technology is relatively lacking.In order to solve this problem,the design of the equipment,the optimization of process parameters,and the analysis of application case are studied in detail.Through the optimization of printing process parameters for different printing materials and different substrates,the printing process parameters window is obtained,and the feasibility of the optimized process parameter window is verified by typical application cases.It provides a reference value for the application and promotion of electric-field-driven jet deposition micro-nano 3D printing technology.The specific works are as follows:(1)According to the basic principles and characteristics of electric-field-driven jet deposition micro-nano 3D printing technology,an electric-field-driven jet deposition micro-nano 3D printer is designed.The equipment mainly includes three-dimensional motion module,observation module,positioning module,printing platform and gas supply module,the feeding module,the power supply module,the upper computer,etc.The equipment has relatively complete functions of positioning,printing,monitoring and post-processing,which can meet the experimental requirements and have the prospect of mass production.(2)The printing process parameters of hard substrates are optimized: when printing the self-made high viscosity(20000m Pa·s)and high silver content(70%-80%)nano silver paste on the glass substrate,the DC voltage is more suitable than the pulse voltage and the AC voltage.The range of process parameters suitable for printing are as follows:the range of voltage are 1500V-1600 V,the range of air pressure are 140 k Pa-160 k Pa,the range of printing height are 280?m-300?m.Under the conditions of voltage 1500 V,air pressure 150 k Pa,printing height 300?m,changing the printing speed can adjust the line width of the printed silver line.When the printing speed reaches 160mm/s,the line width is reduced to below 10?m.The line width is uniform and the shape is good when the line width is above 20?m.When printing the self-made photosensitive resin on the glass substrate,the pulse cone jet printing mode is adopted,and the voltage in the form of DC pulse is used,at a pressure of 6Pa,a printing speed of 0.1 mm/s,and a printing height of 200?m.The appropriate voltage value is determined by orthogonal test to be900 V,and the size of the printed dots can be adjusted by changing the duty cycle.When the duty cycle in the range of 15%-55%,it linearly positively correlates with the diameter of the printed dots.The diameter of the 15% duty cycle is 16.5?m,the holding frequency is 3Hz,the diameter of the dot is 8?m when the duty cycle is 6%,and the diameter of the dot is 0.9?m when the duty cycle is 1%.(3)Optimized the printing process parameters of the flexible substrate: when printing the self-made low-temperature(60?)sintering and stretchable nano silver paste on the PET substrate,the range of process parameters suitable for printing are as follows: The range of voltage are 1200V-1400 V,The range of are 70 k Pa-80 k Pa,and the range of printing height are 300?m-350?m.Under the conditions of voltage 1300 V,air pressure80 k Pa,and printing height 350?m,changing the printing speed can adjust the line width of the printed silver line.When the printing speed is increased to 140mm/s or more,the line width is reduced to below 10?m,and the silver line width is uniformity at 15?m and above.When printing self-made low-temperature sintering,stretchable nano silver paste on paper substrate(photo paper,coated paper,office paper),under the condition of voltage 1300 V,air pressure 80 k Pa,printing height 350?m,the line width decreases with the increase of the printing speed.When the printing speed is 220mm/s,the minimum line width printed is 5.6?m on the photo paper.When the printing speed is 220mm/s,the minimum line width printed is 6.2?m on the coated paper.When the printing speed is170 mm/s,the minimum line width printed is 15?m on office paper.(4)Research on application cases of hard substrate(glass): based on the optimized process parameters window on hard substrate,transparent electromagnetic shielding glass of metal-mesh and microlens array are fabricated,and the electromagnetic shielding effectiveness and transmittance of electromagnetic shielding glass are tested,as well as the imaging quality of microlens array.The correctness of the optimized printing process parameters window on hard substrate is verified.The preliminary application of electric-field-driven spray deposition micro-nano 3D printing in the field of hard substrate printing is presented.(5)Research on application cases of flexible substrate: based on the optimized printing process parameters window on flexible substrate,the flexible electrical heating film of metal-mesh and paper-based circuit are printed.Besides,not only the electrothermal performance of the film is tested,but also multiple silver wires on different kinds of paper-based are stacked and various paper-based electronic samples are fabricated.meanwhile,the preliminary application of electric-field-driven jet deposition micro-nano 3D printing technology in the field of flexible electronic printing is discussed.