Generation and Evaporation of Microsprays

Abstract

This chapter aims to comprehensively review the techniques and features of micro-sprays for various applications via micro-droplet generators over decades, especially focusing on the past and present microfluidics. It is organized briefly as below. The background of current research and development about the micro-spray techniques is first introduced, followed by the generation and evaporation of spray detailed with the concentrated respects of critical requirements for materials and facilities. Then, we address the critical design issues of micro-sprayers such as the actuators and nozzles required to be satisfactory for generating a number of droplets. Subsequently, we further describe characterization of droplets in form of spray concerning droplet size, speed, rates, and patterns in microfluidics. Moreover, the chapter presents the proof-of-concept and commercial applications of the micro-spraying processes, highlighting their current technical progresses and future challenges, which shall be intimately related to the droplet generation and evaporation including droplet evaporative cooling, direct printing, screen printing, nanomaterial coating, liquid nebulization, and miscellaneous employment. Finally, we draw a conclusion in the end of the chapter.

AM of three‐dimensional spongy microstructures for a piezoelectric sprayer

“…1. Introduction: Microsprays or droplets are of much interest over decades in the development of various applications such as inkjet printing [1] and spraying [2] for fabrication of thin films and microdevices [3][4][5]. The liquid of printing/spraying is normally stored in a reservoir containing sponges.…”