US Patent 7178906 Droplet deposition apparatus

An injet printhead is formed by a multistage process: grooves are formed on the base of a block of piezoelectronic material, and a conductor is applied thereto. Conducting tracks are deposited on a substrate with matching spacing, such that the base and piezoelectric material can be joined giving a desired electrical connection. Channels are cut into the top of the piezoelectric block to intersect with the grooves, forming ink chambers, and these are provided with electrodes in electrical contact with the tracks. Cover plates are added to the assembly to provide a manifold and nozzles.