Automated polarimetric microscope

It took me a while, but I decided to make a new printer, which meant dismantling the polarimetric microscope for parts. Even though the printer isn’t ready yet, it was capable of doing xyz and e (for zoom). I’ve been working with new polarimetric sensors that have twice the resolution in x and y, so I thought let’s give it a try once more. 

Today I turned the microscope on myself, boy oh boy polarimetric imaging is NOT flattering AT ALL. Except for the eyes, so here are 2 videos.

As you might have noticed there are some vibrations in the video, these are due to me typing at 1.5m from the printer. It is that sensitive! That makes it even more impressive to me how little vibration there is from the stepper motors when it moves.

The stepper drivers are TMC5160s with microPlyer (interpolation between steps) and StealthChop (noiseless operation at low speeds) technology.

This is my setup. Yes it is messy. Yes that's a piece of lego to stop a pin from shorting...

After some heavy refactoring of the CUDA code the software can now keep up with the framerate! The biggest bottleneck was the pow function in CUDA. I replaced it with a log / exp combo and now it is flying!

I also 3d printed a contraption that controls the magnification of the lens. A NEMA 8 motor is connected to the 3d printer as extruder motor. This means smooth and coordinated moves for X, Y, Z and E. The lens has some drawbacks: it won't keep focus when zoomed, so each zoom is accompanied by a small change in Z to try and keep the lens focused during zooming.

Finally, I made a video and posted it in the details section!

So version 1 is now done! I have made a few pictures that show the potential, I think they are awesome!

I hooked up the microscope lens to the extruder motor, which gives me control of the angle of the lens. The camera has an external shutter option which I hooked up to the fan pins, this allows me to time the captures in between the movements. I am kind of thinking it might be possible to do multiple view geometry of microscopic objects, or stitch the individual images together into superresolution pics. On the other hand it might also be cool to use the extruder motor for the zoom function of the lens and make some cinematic passes of objects.

At the moment the framerate is too low to do this, but I'm working on some CUDA optimizations that should resolve that issue.

Right now, I have to dismantle the thing because I need to do some printing. But next update should be interesting!