Sprayer for Quantitative Application of Odor Stimuli

Abstract

A novel device is described for the quantitative application of chemical stimuli. The device uses ultrasound to disperse a solution of volatile chemicals as an aerosol. A motor-driven syringe controls the rate at which the solution is released from a glass capillary. Vibration of the capillary disperses the released solution into microdroplets that evaporate completely within a few centimeters of the tip. The ratio of chemical stimulus to solvent is maintained until the liquid is dispersed and therefore the release rate of the chemical stimulus can be set and calculated straightforwardly from the dilution factor and the dynamically controllable speed of the syringe plunger. The sprayer permits the delivery of chemical stimulus independent of relative vapor pressures of the components and of environmental factors such as temperature. The sprayer is easy to operate, can be constructed from inexpensive materials, and can be used to emit odor stimuli in the wind tunnel or any other bioassay for pheromones and plant volatiles.