The proposed droplet detection method is based on a media
sensitive and volume dependent capacitive sensing principle as
sketched in Fig. 1. A free flying droplet is introduced between the
two plates of an open plate capacitor driven by an AC voltage. Plate
capacitors are sensitive to changes in the geometrical arrangement
of the plate electrodes or to alteration of dielectric characteristics
[7].
Adispensed droplet, which passes through an open plate capacitor
leads to a change of capacity due to its certain dielectric constant