Piezoelectric dispenser based on a piezoelectric-metal-cavity actuator

Abstract

A piezoelectric dispenser has been fabricated based on the idea of a piezoelectric-metal-cavity ͑PMC͒ actuator. The PMC actuator consists of a metal ring sandwiched between two identical piezoelectric unimorphs. The radial contraction of the piezoelectric ceramic is converted into a flextensional motion of the unimorph, causing a large flexural displacement in the center part of the actuator. With the PMC actuator as a fluid chamber, the large flexural actuation can be used to produce the displacement needed to eject fluid. By applying an appropriate voltage to the piezoelectric unimorphs, a drop-on-demand ejection of ink or water can be achieved. The efficiency of fluid ejection can be enhanced after installing a valve in the fluid chamber. With the simple PMC structure, the dispenser can be operated with a low driving voltage of 12-15 V.

Development of High-Speed Image Acquisition Systems for Spray Characterization Based on Single-Droplet Experiments

“…Applying a double voltage pulse to the piezoelectric element forces a droplet out of the nozzle. A positive voltage sent to the piezoelectric element results in absorption (Lam et al, 2009), and a negative voltage results in pressure in the ejection chamber. In this study, droplets were generated in DOD mode using a glass nozzle ( fig.…”

Note: A novel piezoelectrically driven pipette using centrifugal force

“…4,5 And it is hard for them to handle cross contamination, especially for some dispensers using check valves. 6,7 Another difficulty in using the current piezoelectric dispensing system is that many of the reagents can be very difficult to dispense as a result of air entrainment during loading and usage. 8,9 If the entrapped air bubble is of a critical size, the piezoelectric dispenser cannot provide enough acoustic energy to dispense droplets of liquid and the system must be manually evacuated and reloaded with reagent.…”