A 3D Printable Microscope With Dynamic Pattern Illumination

We explored the utility of a video projector as the source of dynamic pattern illumination for a 3D printable microscope in conjunction with a Raspberry Pi module and camera system. This setup provides a low-cost solution in achieving different contrast-enhancement modalities, including dark-field, Rheinberg illumination, oblique illumination, and polarization microscopy. In commercially available microscopes, these methods are possible through the use of specialized physical filter attachments that typically add to the cost of the microscope. With our microscope design, the physical filters are replaced by projecting an illumination mask/pattern on the back focal plane of the microscope’s condenser lens. Our design also provides for ease in switching from one contrast-enhancement method to another with no optical re-alignment, as this can be done with a click of the button on a PC. We will demonstrate that in using the different illumination patterns with varying colors it is possible to highlight and optically stain the details of an unstained, transparent specimen. Furthermore, we will discuss how our system produces color-coded information regarding the birefringence of our samples within a single image.