Multiplexed electrospray deposition apparatus capable of delivering picoliter volumes of one or more substances is disclosed. The apparatus may include a unitary planar dispenser etched from a silicon wafer through microfabrication or micromachining technology. The apparatus may be used as a deposition tool for making protein microarrays in a noncontact mode. Upon application of potential difference in the range of 7-9 kV, the substances may be dispensed directly, not through a collimating mask, onto a substrate with microhydrogel features functionalized with an anchoring agent.