Optical sectioning robotic microscopy for everyone: the structured illumination microscope with the OpenFlexure stages

Abstract

We report on the 3D-printed structured illumination microscope (SIM) with optical sectioning capability. Optically sectioned images are obtained by projecting a single-spatial-frequency grid pattern onto the specimen and recording three images with the grid pattern at different spatial phases, and then post-processing with simple mathematics. For the precise actuation of the grid for the structured illumination and the positioning of the sample, stages of the open-sourced, 3D-printable OpenFlexure families, which are capable of highly precise positioning control of tens of nanometers based on the flexure mechanism of the flexible plastics, are utilized. Our system has optical sectioning strength of a few microns, which is equivalent to that achievable with the confocal microscopes. The operation of our system can be automated with the Raspberry Pi and can be remotely operated from a PC via a wireless local area network.