A fluid mover includes a chamber with one or more outlet openings, first and/or second fluidic diaphragm(s) having a portion movable in the chamber to cause fluid to move at the outlet opening, and a coil assembly magnetically coupled to the fluidic diaphragm to move the movable portion of the fluidic diaphragm(s) in response to a current in the coil. The coil assembly includes a coil with an opening, and a plug may be positioned in the opening and/or a support may be positioned around a periphery of the coil. The plug and/or the support may have a magnetic permeability greater than one and be arranged so magnetic field lines created by the coil pass through the plug and/or support. The coil, plug and/or support may define a flat surface, e.g., such that a uniform gap is present between the diaphragm(s) and the coil, plug and/or support.