Droplet pinchoff inside a tube: applications for droplet-on-demand devices*

Recent Droplet-on-demand (DOD) devices use a voltage pulse on a piezoelectric disk to eject droplets from a nozzle.  By replacing the standard nozzle with a short tube, doplet pinchoff can occur within the tube when activating the piezoelectric disk for certain pulse amplitudes and pulse widths.  We will present the dynamics of droplet pinchoff inside the tube and its effect on droplet size in a modified DOD device.