The microdrop technology uses the principle of the ink jet printing technology. The core of the microdrop dispensing head consists of a glass capillary which is surrounded by a tubular piezo actuator. At one end the capillary is formed to a nozzle (diameter 30 to 100 μm). Applying a voltage pulse, the piezo actuator contracts and creates a pressure wave which propagates through the glass into the liquid.
In the nozzle region the pressure wave accelerates of the liquid. A small liquid column leaves the nozzle, breaks off and forms a droplet which flies freely through the air. Depending on the nozzle sizes (30 to 100 μm) volumes of 25 up to 500 pl (corresponding to drop diameters of 35 to 100 μm) are generated.