Experimental investigation of controlled microdroplet evaporation toward scalable micro/nanomanufacturing

This article focuses on an experimental investigation of microdroplet evaporation as a step toward developing a scalable droplet-based micro/nanomanufacturing process. A customized direct-write inkjet setup is utilized to generate monodisperse microdroplets for two fluid types (acetone and distilled water). The microdroplet evaporation dynamics was studied using a light-emitting diode strobe-based high-speed photography. The microdroplet was heated using convective heat transfer via a resistive heating ring fixture that controlled the heat flux. The effect of nozzle size and fluid type on microdroplet size reduction was investigated. The output responses include percentage volume reductions, drop size shrinkage, and changes in the surface-to-volume ratio. The experimental results were validated with an equivalent theoretical model and close agreement between the results was obtained. This research provides a basic understanding of the evaporation dynamics of microdroplets and is a precursor toward their transition to the sub-micro meter and nano regimes.