PipeJet™ - A SIMPLE DISPOSABLE DISPENSER FOR THE NANOLITER RANGE

This paper reports for the first time on an unrivalled simple, disposable non-contact dispenser for the nanoliter range. In contrast to other known dispensers manufactured by silicon micromachining [1-4] the new device simply consists of an elastic polymer tube with circular cross section. Actuation is done by a piezostack driven piston, squeezing the tube at a defined position nearby the open end by a significant fraction of the cross section. In contrast to drop-on-demand devices based on an acoustic actuation principle [5] this leads to a significant mechanical displacement of the liquid. In our experiments we successfully tested ten media in the viscosity range from 1 mPas to 27 mPas and even up to approximately 200 mPas with a new actuation setup. Frequency characteristics showed an independent dosage volume for water up to a frequency of 15 Hz. Standard deviation within 1,000 shots resulted in an excellent CV of less than 2% of the dosage volume. With a print frequency of 340 Hz a flow rate up to 143 µl/s has been reached. Beyond the possibility to dispense highly viscous fluids also emulsion paints with particles of approximately 40 µm diameter have been printed successfully.