Focused acoustic radiation, referred to as tonebursts, are applied to a volume of liquid to generate a set of droplets. The droplets generated are substantially smaller in scale than the focal spot size of the acoustic beam (e.g., the frequency at which the acoustic transducer operates). Further, the droplets have trajectories that are substantially in the direction of the acoustic beam propagation direction. In one embodiment, a first toneburst is applied to temporarily raise a protuberance on a free surface of the fluid. After the protuberance has reached a certain state, a second toneburst is applied to the protuberance to break it into very small droplets. In one embodiment, the state of the protuberance at which the second toneburst is supplied is the time period shortly after the protuberance reaches its maximum height but before the protuberance recedes back into the volume of fluid.