Applications of Stepper Motors for Thin Film Synthesis Through Programmable Dip-Coater

The dip-coating process for thin film synthesis is a widely used technique for developing even layers of a Sol-Gel polymer. This research investigated the development of a dip-coater utilizing a NEMA stepper motor attached to a linear rail guide with a simple relay circuit. A comprehensive breakdown and modern mode of the operation of stepper motors was studied. The polarization of the stator poles and subsequent alignment within the stepper motor were determined and visually represented with a single-step assembly. The stepper motor was programmed by a Raspberry Pi 5 through C code. The developed C code was compatible with any four-wire stepper motor for open-source usage. The thickness of the layers of the thin film after each dip was calculated through gravimetric analysis. The Sol-Gel thin films were then doped with tetra-hydroxyphenyl porphyrin (H2THPP) and characterized using UV-Vis spectroscopy to determine optimum concentration.