Piezoelectric dispenser with a longitudinal transducer and replaceable capillary tube

A dispenser for transferring a predetermined quantity of a liquid, comprising:

• a longitudinal transducer, comprising:
• a capillary tube comprising polyether ether ketone (PEEK) and having a tip at a distal end of the capillary tube;
• a piezoelectric actuator operatively coupled to the capillary tube at a location proximal of the tip;
• an aperture at the tip of the capillary tube;
• and
• a flexible supply line located upstream of the capillary tube and configured to couple to and supply the liquid to the capillary tube;
• wherein actuation of the piezoelectric actuator causes a pressure wave to propagate from said location of the capillary tube toward the tip of the capillary tube such that radial motion at said location of the capillary tube is transmitted as distally extending axial motion of the tip of the capillary tube, thereby causing a droplet of a predetermined volume to be ejected from the aperture;
• wherein the capillary tube has a modulus of elasticity configured to dampen acoustical noise from the actuation and provide single drop stability over a range of drop sizes above and below a single droplet size corresponding to borosilicate glass capillary tubes having a diameter of the aperture equal to the diameter of the aperture of the capillary tube.