The present invention provides a method and device for the acoustic ejection of fluid droplets from each of a plurality of fluid-containing reservoirs. The droplets are ejected toward sites on a substrate surface for deposition thereon. The device is comprised of: a plurality of reservoirs each adapted to contain a fluid; an ejector comprising a means for generating acoustic radiation and a means for focusing the generated acoustic radiation so as to eject fluid droplets from the reservoir fluids; and a means for positioning the reservoirs in acoustically coupled relationship to the ejector. The invention is useful in a number of contexts, particularly in the preparation of biomolecular arrays.