An electrostatic actuator for use with an adjacent chamber having an orifice in order to eject fluid from the orifice of the chamber, the electrostatic actuator comprising: a plurality of rigid conductors (44,74) arranged on a bonding surface of a substrate of the electrostatic actuator, wherein the plurality of rigid conductors (44,74) are associated with the chamber, and wherein the plurality of rigid conductors (44, 74) are arranged adjacent to one another and in use along the adjacent chamber; a plurality of conductive blockers arranged on the bonding surface of the substrate and positioned between each of the conductors (44,74); a conductive layer comprising: a flexible conductive membrane forming at least part of a wall of the chamber in use such that flexing the flexible conductive membrane changes the volume of the chamber; and a plurality of bumps; and a drive circuit operably connected to each of the conductors (44,74) and the conductive layer, configured to selectively apply a voltage between each of the conductors (44,74) and the conductive layer to generate a varying electrostatic force that flexes the flexible conductive membrane in a desired pattern to eject fluid drops from the orifice in the chamber; wherein the flexible conductive membrane is disposed opposite to and spanning the plurality of rigid conductors across a gap between the substrate and the conductive layer, such that each of the plurality of bumps is located over a corresponding one of the plurality of blockers across the gap; and a voltage source configured to hold the conductive blockers and the bumps at the same voltage. a plurality of rigid conductors (44,74) arranged on a bonding surface of a substrate of the electrostatic actuator, wherein the plurality of rigid conductors (44,74) are associated with the chamber, and wherein the plurality of rigid conductors (44, 74) are arranged adjacent to one another and in use along the adjacent chamber; a plurality of conductive blockers arranged on the bonding surface of the substrate and positioned between each of the conductors (44,74); a conductive layer comprising: a flexible conductive membrane forming at least part of a wall of the chamber in use such that flexing the flexible conductive membrane changes the volume of the chamber; and a plurality of bumps; and a drive circuit operably connected to each of the conductors (44,74) and the conductive layer, configured to selectively apply a voltage between each of the conductors (44,74) and the conductive layer to generate a varying electrostatic force that flexes the flexible conductive membrane in a desired pattern to eject fluid drops from the orifice in the chamber; a flexible conductive membrane forming at least part of a wall of the chamber in use such that flexing the flexible conductive membrane changes the volume of the chamber; and a plurality of bumps; and a drive circuit operably connected to each of the conductors (44,74) and the conductive layer, configured to selectively apply a voltage between each of the conductors (44,74) and the conductive layer to generate a varying electrostatic force that flexes the flexible conductive membrane in a desired pattern to eject fluid drops from the orifice in the chamber; wherein the flexible conductive membrane is disposed opposite to and spanning the plurality of rigid conductors across a gap between the substrate and the conductive layer, such that each of the plurality of bumps is located over a corresponding one of the plurality of blockers across the gap; and a voltage source configured to hold the conductive blockers and the bumps at the same voltage.