Abstract: There is disclosed a piezoelectric droplet maker that is driven at high frequency and energized with high power and high frequency Operational Amplifier (OP-AMP) electronics. The droplet maker implements a method of producing jets of uniform droplets of solution precursors (or any other homogeneous liquids). The formation of droplets results from stream break up due to the disturbance of liquid jets by the piezo actuator as they leave an orifice. This disturbance can be electronically tuned to produce uniform droplets with high repeatability. In another aspect, the droplet maker can be used to inject axially uniform diameter solution precursor droplets into process gas flow of a microwave plasma apparatus.