Design of Airflow Assisted Spinneret for Electrohydrodynamic Direct-Writing

Electrohydrodynamic direct-writing (EDW) is a growing technology for the printing of functional materials in diverse range of applications. Improving the deposition accuracy of EDW jet is of importance in the practical processes. This paper presents an airflow assisted spinneret for the high resolution electrohydrodynamic direct-writing. An assisted laminar co-flow air is introduced to the spinneret to increase the stability of EDW process. This airflow provides an additional stretching and constraint force on the jet to make the ejection in a straight trajectory, since the surrounding interferences can be reduced and the stability can be enhanced. A flow field model is conducted to simulate the airflow distribution and velocity to direct the structure design of spinneret. Experimental results verify the spinneret design and demonstrate a stable ejection in EDW process. With the assistance of airflow, the uniformity of printed patterns and the stability as well as the deposition position accuracy of charged jet can be improved. In addition, complex patterns with position errors less than 5% are generated and characterized, which provides an effective way to promote the integration of micro/nano systems.