Inkjet Printing of Viscous Monodisperse Microdroplets by Laser-Induced Flow Focusing

Generating microdroplets of viscous fluids is crucial to ``drop-on-demand'' applications ranging from inkjet printing to additive manufacturing, but is dogged by the clogging of microscale nozzles. In this study a flow-focusing phenomenon, resulting from a laser-induced shock wave, is used to produce monodisperse viscous droplets smaller than the nozzle from which they fly. The authors prove that this technique can even be used to print a biologically relevant sample without spoiling its functionality.