A Pneumatic Drop-on-Demand Printing System With an Extended Printable Liquid Range

Applications of drop-on-demand (DOD) printing are restricted by the required properties of the liquid. Printability is estimated using the Z-value that considers liquid properties and orifice size. In DOD inkjet systems, the printing materials must have 1 < Z < 14. We used a flexible membrane and a backflow stopper in a pneumatic DOD printing system to eject liquids with 0.23 <= Z <= 84.77. To investigate how our system can form droplets in the extended printable range, the behaviors of droplet formation were analyzed using in situ monitoring.