Piezos and Pulses

How does the Drop come out?

Deflection of a piezoelectric ceramics on a GeSiM dispenser

Deflection of a piezoelectric ceramics on a GeSiM dispenser

The dispensers (also called “pipettes” or “jets”) follow the drop-on-demand principle, i.e., a drop is released exactly when the piezo ceramic actuator is triggered. This results in the bending of a silicon diaphragm behind the actuator and this in turn leads to a compression of the liquid inside the “pump chamber” and hence to the ejection of a droplet from the nozzle. After this, the ceramic returns to its initial state and the dispenser is refilled with liquid from the inlet. No valve is involved in this process.

Basically this process only works for low-viscous liquids up to a viscosity of about 5 mPa*s (5 cP). Liquids with lowering viscosity at elevated temperature may be used with our heatable dispensers.