US Patent 7988261 Printhead having layered heater elements and electrodes

A printhead is provided having nozzles and heaters having heater elements and electrodes connecting current from a power source to the heater elements to heat, and form gas bubbles in, liquid within the nozzles which causes ejection of the liquid from the nozzles. The heaters are formed of layers of a single material. A first layer of the single material has portions of different thickness respectively defining the heater elements and electrodes. A second layer of the single material overlaying and spaced from the first layer has a single thickness defining the electrodes.