Conclusions
Electrospraying was proved to be a versatile tool for various material processing technologies. A number of established and emerging electrospray applications for thin film deposition have been presented. The goal of this review was to provide a summary of electrospray applications in thin solid film deposition. A large number of examples of practical significance, or only laboratory-scale experiments have been given. The presented methods are compared in Tables 1 and 2. Electrospray has advantages of uniform coating of large areas, inexpensive equipment, operation at atmospheric conditions, and easy control of deposition rate and film thickness by adjusting voltage and flow rate. Advances in electrospray applications in thin film deposition will certainly continue in near future, particularly in nanotechnology and biotechnology, and new achievements in this field can be expected. However, there are still a number of challenges to be faced, needed for commercial thin film production.
One of such problems is a specific electrospray mode control. Electrospray is very sensitive to the liquid physical properties and the electric field in the vicinity of the emitter tip. The issue of continuous control of spray modes has been undertaken by Valaskovic et al. An orthogonal opto-electronic system based on the spray plume observation in certain characteristic cross sections, which controls the applied voltage has been developed. For further development in MEMS, nanotechnology, and nanoelectronics it will be necessary to develop the direct patterning techniques for the deposition of thin layers of pattern size finer than 1 lm. Although an attempt was made to consider wide spectrum of relevant refereed papers, the literature cited in this paper is by no means complete. However, the author believes that it should provide the reader with the development and application of electrospraying, including LMISs, in thin film deposition.