The Analysis And Suppression Of Cross-talk And The Method Of Addressable Jetting In Muti-nozzle Electrohydrodynamic Inkjet Printing Head

Electrohydrodynamic printing is a promising technique for printed electronics application due to its high resolution and wide viscosity range.Most researchers working in this field are using a single nozzle configuration,efficiency of which cannot meet the needs of industrial production.The use of arrayed nozzles is an effective way to solve this problem.However,the cross-talk in the nozzle array seriously affects its printing performance,and the existing method for addressable printing cannot be applied to the precise drop-ondemand mode.Herein,this dissertation reduces cross-talk by optimizing process parameters and nozzle parameters,introducing “dumb” nozzles,and executing ignition timing control.Addressable muti-nozzle printing is achieved by applying independent voltage to each nozzle,and high-precision printheads are made through MEMS technology,which can be used for high-resolution drop-on-demand(DOD)printing.The specific research work is as follows:Firstly,the cross-talk in the nozzle array is analyzed and suppressed.The influence of parameters related to process(voltage,air pressure,printing height)and nozzle(nozzle length,nozzle spacing)on electric field cross-talk has been studied through experiments and simulation methods.Through it,the parameter selection interval that can reduce the crosstalk has been found.The electric field distribution is optimized and the “end effect” is reduced by introducing “dumb” nozzles.On this basis,Si-nozzles have been designed and made for high-resolution parallel printing.Secondly,a printing control method of addressable nozzle array through applying independent voltage to each nozzle is proposed.The applicable scope of this method is given through theoretical calculations,and the manifestation of cross-talk in this case is analyzed through experiments and simulations.To improve printing performance,an optimization method of voltage and controlling ignition timing is proposed,which can reduce the crosstalk.On this basis,a ceramic print head is designed and prepared,which is can addressable and can achieve high-resolution DOD printing.Thirdly,a set of addressable muti-nozzle inkjet printing system is built.This system includes printhead module,substrate and motion module,ink supply module,high voltage control module,vision module,etc.The printhead module can ensure high-precision installation and multi-degree-of-freedom movement.The observation module can capture the printing process by high magnification lens and high speed camera.The ink supply module can provide stable ink supply and high-precision positive or negative pressure support for the printhead.The high-voltage control module can provide multiple switchable high-voltage signals.Finally,The results of high-efficiency DOD printing have been achieved by this inkjet printing system.