3D microfluidics spray nozzle for sample processing and materials deposition

Abstract

Spray atomisation is a highly versatile materials processing method that has found applications in the pharmaceutical, food, chemical, electronic and automotive industries. However, common commercial spray nozzle systems offer little processing flexibility and usually require large amount of liquid. Microfluidics-based spray nozzles, that have a small dead volume and that can incorporate mixing, filtering or dilution functions have the potential to open up interesting opportunities for advanced materials processing as well as analytical chemistry and biology. In this study, we propose a flexible 3 dimensional microfluidic spray nozzle fabricated using soft-lithography. The nozzle, whose performances are comparable with commercial systems, generates ultrafine, sub-picolitre droplets and enables the deposition of homogeneous layers over large areas. The droplets dry so quickly that no coalescence is observed for flow rates up to 500μL/h when the spray is positioned 8cm from the substrate. The amount deposited can be controlled by varying the flow rate and deposition time.