A printhead is provided for an inkjet printer. The printhead includes a wafer assembly supporting rows of ink ejection nozzles. Each nozzle includes a nozzle structure defining a nozzle chamber in fluid communication with an ink ejection port. A cantilevered thermal actuator terminates in a free end over an ink supply channel. The thermal actuator includes a serpentine heater layer connected to a CMOS drive circuitry layer of the wafer assembly. The CMOS drive circuitry layer is configured to actuate the thermal actuator and reciprocate the actuator to eject ink in the nozzle chamber out through the ink ejection port.