The Investigation Of Emitted Current Detection For Electrohydrodynamic Jet Printing

Electrohydrodynamic jet printing(E-Jet printing)is a non-contact material forming technology with many advantages,such as high resolution,wide ink adaptability,which is already been used for metal,polymer and ceramic micro/nano-structures.It has huge potential on manufacture of electronics,biological materials and structures,and also is an effective method for the preparing micro/nano-structures.The parameters control for E-Jet printing has key effects on precision and micro-morphology,which is an importmant part for stable printing and is difficult.Here,the emitted current measurement method is adoped to realize the parameters control.In this paper,the emitted current measurement equipment was designed and built for E-Jet printing process,the current characteristic for continuous and drop-on-demand printing was studied,the goal of using current measurement to monitor the printing size and stability is realized,and microstructures are printed.First of all,the formation mechanism of emitted current is analysed,current measurement circuit of E-Jet printing was setup,and the emitted current measurement equipment was designed and built,the parameters of the current monitoring equipment were adjusted correctly,the software programming based on the current measurement equipment is completed and the realtime current measurement and display were realized.And the software programming of the E-Jet printing platform realized the integration control of voltage,wodking distance and flow rate and printed a variety of graphene micrograph.Then,the current measurement and experiment research for E-Jet continuous was carried out using the current measurement equipment.In cone jet mode,graphene was used as printing ink,the functional relations between current and flow rate,the flow rate and printing size were setup.Next,the functional equation of current and printing size is deduced to monitor and display the printing size in real time.The monitor method of printing size was used in PCL/PVP composite solution for cone jet printing.And the PCL/PVP lines were printed with the size of 55?m,79?m,102?m,respectively.The relative error between the predicted value and actual value was less than 1%.The real-time monitoring for cone jet mode is realized.Finally,the current characteristic of drop-on-demand printing was investigated.The effects of parameters on the emitted current and printing size was discussed,the current law of microdripping mode was analysed,and the relation between emitted current and printing stability was investigated.It was found that when the current value was in the range of 46.65pA-263.93 pA and the standard deviation was less than 15,the printing was carried out smmothly.The minimum printing size of 83?m of graphene microarray for microdripping mode was obtained.