Optimal algorithm for spray pyrolysis deposition of TiO2 films by using an industrial robot

Abstract

This paper approaches the optimization of the spray pyrolysis deposition (SPD) using an industrial robot. The purpose is to develop an optimal algorithm for obtaining uniform films on a planar surface. The design objective refers to the uniformity of the film, the aim being to optimize the difference in thickness between two specific points on the sample. The characteristic parameters of the SPD process (the substrate temperature, the height of spraying cone, the spraying angle, the carrier gas pressure, the trajectory step, the time between two passes, and the number of consecutive passes on the substrate) are used as design variables in the optimization. The investigation strategy is based on a design of experiments technique (Plackett-Burman), obtaining the appropriate regression function. The goodness-of-fit has been verified by computing the variance in the predicted results versus the real data, the probability that the fitted model has no useful terms, and the significance of the regression. Experimental results are used to validate the optimization algorithm.