Precision metered solenoid valve dispenser

摘要

A reagent dispensing apparatus is provided including a positive displacement syringe pump in series with a solenoid valve dispenser. The pump is controlled by a stepper motor or the like to provide an incremental quantity or continuous flow of reagent to the solenoid valve dispenser. The solenoid valve is opened and closed in at a predetermined frequency and duty cycle to dispense droplets of reagent onto a target substrate at the metered flow rate.