Experimental Research On Flexible Substrate Of Electrohydrodynamic Jet Printing

In recent years,the demands for low-cost,large-area,flexible and easy-to-manufacture electronic devices are increasing day by day in the field of life and engineering,the flexible electronic technology has attracted research and attention from many scholars.In many flexible electronic patterning processes,the Electrohydrodynamic Jet Printing(EJP)technology uses a solution process to be compatible with large-area printing and roll-to-roll manufacturing,which greatly improves manufacturing efficiency and reduces costs.Polymer substrates are the most widely used materials in flexible electronic substrates.However,due to the problems of polarization and charge accumulation in the printing process on the polymer substrates,the stability of EJP is broken.In order to print patterns continuously and stably on the polymer substrates,this article designs and manufactures electrostatic focusing electrodes,which effectively overcomes the effect of substrate effects on EJP.In addition,a combined nozzle is designed and manufactured to reshape the electrostatic field around the nozzle.The effect of polarization and charge accumulation on the EJP of the flexible substrate is weakened by reshaping the distribution of electrostatic field around the nozzle,besides further studying the influence of process parameters on printing microstructures,and the micro-patterns on the flexible substrate PET were realized via electrohydrodynamic drop-on-demand printing.The specific research contents are as follows:First,a set of experimental equipment for EIP was developed,and a fluid control device for different viscosities fluid was designed and manufactured to solve the problem of blocking the pipeline for high viscosity ink.A set of control system for EJP platform is developed,which integrates the control of each functional module,and provides a solution to print any complex two-dimensional patterns on flexible substrates via electrohydrodynamic drop-on-demand printing.Then,the uniaxial focusing electrode simulation model was established using COMSOL software.The effect of different voltage waveforms applied on the focusing electrode on the jet was simulated and analyzed.An experimental study on the printing effect of focusing electrodes with or without focusing electrodes and different inner diameters was carried out.The research results show that the focusing electrode can focus the jet,and the inner diameter of the focusing electrode greatly affects the focusing effect.Finally,the COMSOL software was used to simulate and analyze the different jet behaviors of metal needle and combined needle on the flexible substrate PET,and the experiment verified that the combined needle was more conducive to flexible substrates.The process parameters such as pulse voltage amplitude,duty cycle,flow,working distance,and platform moving speed have been studied on the printing microstructure.Then,using the optimized printing parameters,a variety of micro patterns were printed on the flexible substrate PET via electrohydrodynamic drop-on-demand printing technology.