Heat transfer apparatuses and methods for directing heat transfer are disclosed. A heat transfer apparatus includes a vapor chamber having a first surface and a second surface where the first surface and the second surface define a chamber space and at least one of the first surface and the second surface includes a hydrophilic coating. The heat transfer apparatus also includes one or more first ultrasonic oscillators coupled to the first surface, one or more second ultrasonic oscillators coupled to the second surface, and a controller having a non-transitory, processor-readable storage medium storing programming instructions for selectively activating the one or more first ultrasonic oscillators or the one or more second ultrasonic oscillators based on an intended direction of heat flux.