| Electrohydrodynamic jet printing is widely used in high-precision fabrication of micro and nano functional structures in flexible electronic devices due to its micron-level high resolution.The traditional single nozzle printing efficiency is low,and the parallel printing of multi-nozzle can effectively improve the preparation efficiency,but it faces the problem of jet interference.To solve this problem,this article proposes a nozzle structure that suppresses the jet interference.It verifies the rationality of the design through two aspects of numerical simulation and experiments,and completes the production of multi-nozzle nozzles.The application of array printing is explored.The specific research work is as follows:First of all,the basic principles of the electrohydrodynamic jet printing technology and the injection situation under different conditions are explained,and the process and force of the formation of the cone jet are briefly analyzed.Through theoretical analysis,the interface tracking method of electrohydrodynamic jet printing is determined,and the mathematical model of hydrodynamics and electrodynamics is established.Based on this theory,the physical model of multinozzle electrohydrodynamic jet printing is established by multi-physical field coupling software,which lays the foundation for the numerical simulation analysis.Secondly,the finite element analysis of the jet of multi-nozzle electrohydrodynamic jet printing is carried out.Electrohydrodynamic jet printing with three nozzls is simulated,and the effect of "interference effect" on printing is preliminally understood.Through the analysis of its mechanism,a parallel nozzle array with double round auxiliary electrodes at both ends is proposed.The feasibility of the proposed scheme is verified by fluid analysis and electrostatic field aided analysis of multi-nozzle electrohydrodynamic jet printing under different configurations.Furthermore,the scheme is extended to three-dimensional array,and it is concluded that adding two round electrodes on the outside of the isometric nozzle array can also make the nozzle print normally without being affected by the interference effect.Finally,the idea of using the interference effect make the jet shift to the medial side is proposed,and the value of this idea is proved by preliminary research.Then,an electrohydrodynamic jet printing experiment platform is established for experimental verification,and the jet angle and droplet array generated by parallel three-nozzle printing under different configurations are studied.The results show that:Compared with the traditional method of "adding single flat head auxiliary electrodes at both ends",the proposed method has obvious advantages in interferen ce suppression.When the nozzle spacing is 0.5mm,the 2.8° jet offset angle and the Taylor cone angle difference on both sides 3.3° generated by the former outer nozzle can be reduced to 0° and 0.05° respectively by the latter.Moreover,the droplet array printed by the latter has no offset and the droplet size is relatively uniform.In addition,experiments are carried out to make the jets of both nozzles tilt inward by using the interference effect,which proves the feasibility of "reverse utilization" of the interference effect of multi-nozzles electrohydrodynamic jet printing.Finally,on the basis of numerical simulation,a method of making a multi-nozzle with a consistency of printing is proposed.The glass substrate is treated by OTS hydrophobic treatment method,and the special substrate with large contact angle between the printed solution and the glass substrate and the phenomenon of satellite-free droplet scattering is obtained.A 5×5 microlens array with an average diameter of170.1μm is fabricated by electro-fluid printing on hydrophobic substrates using a five-nozzle print head with double auxiliary electrodes.The arrangement,size and imaging effect of the microlens array are analyzed,and it is proved that the multinozzle nozzle that can suppress the crosstalk effect has great application potential. |
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