Dimensional Accuracy of Photo-Curing (LCD) Microprinting

The study investigates the dimensional accuracy of photo-curing (LCD – liquid crystal display) microprinting, as well as the geometries possible to obtain in a repeatable manner through the before mentioned method. LCD technologies rely on the photopolymerization effect induced by UV light patterns projected through a liquid crystal screen. This method is known for its capability of producing high-quality surface finish and fine details (in comparison to material extrusion 3d printing methods). Quality of the part can be influenced by various factors, including the screen resolution and pixel size, light intensity distribution, resin composition, its type, its properties and exposition time, to name a few. To comprehensively understand these effects, authors conducted a series of experiments, to quantify the dimensional deviations and amount of geometrical defects in comparison to intended designs (the model). Various geometric shapes with critical dimensions ranging from tens to hundreds of micrometers were printed using different manufacturing settings. The results were analyzed to identify the primary contributors to dimensional deviations and to assess the limitations of the process. Our findings reveal that high levels of precision with very fine structures (approximately 30-40 micrometers in the smallest dimension) can be achieved, but proper resin selection, as well as processing parameters, including digital model preparation, have to be picked. The study provides insight into photo-curing LCD microprinting, expanding its applicability in precision engineering and microdevice fabrication.