Drop-On-Demand Inkjet Printing of SU-8 Polymer

This paper presents drop-on-demand inkjet printing of SU-8 on functionalized surfaces for direct printing of computer controlled polymer patterns. The high viscosity of SU-8 required an in-depth investigation of the print parameters such as pulse amplitude, pulse length and temperature in the piezo-actuated nozzle. The results show that the optimal drop velocity to obtain a stable printing is ∼2 ms-1 which corresponds to pulse amplitude and length of 220 V and 70-80 μs, respectively. The diameter of the SU-8 drop was reduced from 117 μm on non-treated silicon to 58 μm on a surface terminated by a silane-based self-assembled monolayer.