The fabrication of integrated and three-layer SU-8 nozzles for electrohydrodynamic printing

Electrohydrodynamic (EHD) jet printing can fabricate high resolution micro- and nano-scale lines with low cost and simple procedure. However, less attention has been paid to the fabrication of integrated nozzles with low cost and volume production capacity. In this work, three-layer SU-8 nozzles with slot dimension ranging from 10 to 50 mu m were fabricated by ultraviolet photolithography and thermal bonding methods. The influence of the thicknesses (bottom and top layers) on the deformation of SU-8 nozzle was studied by numerical simulation. The results show that the suitable thicknesses should be 60 and 10 mu m for bottom and top layer, to ensure the fabrication quality of SU-8 nozzles. Based on the established EHD printing platform, PEO (Polyethylene Oxide) lines with line-width from 750 nm to 8.2 mu m can be printed by using the fabricated SU-8 nozzles, indicating the indicating the practicality of developed nozzle fabrication method.