Meniscus Motion Inside A DoD Inkjet Print-Head Nozzle

Abstract

A new study of the jetting performance for drop-on-demand (DoD) inkjet print heads investigated meniscus motions inside the transparent nozzles of MicroFab inkjet print heads. A composite image representation of the observed meniscus motions, imaged at high resolution using a spark flash light source, was developed for our subsequent analyses of the influences of drive voltage and pulse dwell time and also the ink properties. At higher drive voltages a slow damped refill (following de-pinning of the meniscus from the very edge of the nozzle exit) was also clearly observed. This and many other interesting phenomena were observed with the composite images: internal bubbles that progressed through the nozzle region over relatively long timescales, internal break-off of the jet from the meniscus surface, satellite formation and merging, and the contact line de-pinning not previously observed before..