An inkjet printhead that has an array of droplet ejectors, each having a chamber with a nozzle and an actuator for ejecting drops of ink through the nozzle. During use, each of the chambers hold ink and a gas, the gas remaining in the chamber during activation and deactivation of the actuator. The actuators each have a part with a hydrophilic coating for contacting ink in preference to other parts of the actuator such that the gas and the ink are in direct contact with each other at an interface within the chamber, and at least part of the actuator is positioned at the interface between the ink and the gas. By insulating at least some of the actuator from the printhead substrate, more heat is directed into the ink that is ejected from the nozzle. If the actuator is a thermal or thermal bend, the insulating fluid allows the resistive elements to heat more quickly and use less power. This reduces the overall power consumption of the printhead.