Multinozzle electrospray method for high-throughput and uniform coating: Application of superhydrophobic coating

Electrospraying is an effective method of producing functional layers on substrates. By means of electrospraying, it is possible to create uniform and fine droplets that attract to the substrate without being blown away by the electric field formed by the nozzle and the substrate. The uniformity of the coated layer is rarely affected by a fluid drying process (such as Marangoni flow on substrates) as the size of droplets can reach micron/nano-levels and the solvents in the droplets can evaporate quickly. Therefore, the electrospray process is often referred to as ‘dry deposition.’ However, when an electrospray system with multinozzles is considered for the faster process of producing large substrates, the drying process may be completely different than for a single-nozzle system. In addition, crosstalk and nonuniform spray volume from each nozzle can pose an additional problem that needs to be addressed. In this study, we proposed a multinozzle electrospray system and process to average the spray amount heterogeneity and achieve layer uniformity in a fast-drying process. Finally, we demonstrated the effectiveness of our proposed methods by fabricating superhydrophobic layers on a highly insulating substrate.