A printhead integrated circuit includes an ink chamber for storing a fluid; an ink ejection port in fluid communication with the ink chamber; a plurality of actuators radially positioned about the ink ejection port in a petal formation; and a heater structure provided in each actuator, the heater structure operable to conduct current therethrough to heat a respective actuator, whereby a differential thermal expansion is established in the respective actuator to urge the respective actuator into the ink chamber. The heater structure is positioned in each actuator to heat the actuator unevenly.