Project: DIY Superresolution Microscope (SIM – Structured Illumination Microscopy)

Back when I was in Japan (look here for more details: https://connectingjapandgermany.wordpress.com/) I had the chance to work for one of the best optic companies in the world. Nikon. I was able to spend two weeks in the life science department and was able to do some research. It was the first time to here somehting like superresolution microscopy. In university you always learn everything about the abbe-criteria and the maxima resolution given by (Wikipedia):

\sin(\delta_\varphi)=1{,}22\frac{\lambda}{D}
\delta_\varphi : minimaler Winkel
\lambda : Wellenlänge der beobachteten Strahlung
D : Öffnungsdurchmesser

With tricky illumination and post-processing you can more-less easily double the resolution. Therefore you’re illuminating the object with a sinusodial pattern varied in phase and space. In the fourier domain of the recorded pictures, You’ll get the equivalent phase distribution, which can be superpositioned to a spectrum whichs OTF has half of the original one. This means, that the PSF of the Microscopes lens halfs just by doing some computation.

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Driving a Stepper with Arduino, Labview and a H-Bridge (L298N) (LIFA)

For a project in university I had to drive a stepper Motor which drives a wormdrive. By varying the Z-Position, I wanted to find the focus of an electrical tunable lens from Optotune. I needed an easy setup for the correlation between current of the lens and focal power. The tunable lenses company provides a c# and labview interface. I’m not an expert in either both cases, but I’m more familiar with LabView, as i t was part of my bachelors thesis. So the logical step was to combine the USB-Lensdriver for the tunable lens with the arduino which can be used in Labview. The Magic-Word is LIFA (Labview Inteface for Arduino can be found here: https://decibel.ni.com/content/groups/labview-interface-for-arduino). After installing and playing around, I found out, that the given Stepper Example is only for Easy Driver Boards. Mine was a simple H-Bridge. So it’s more less an amplifier for the given Input signals. The sequence for driving the Stepper has to given by a controller board (The Arduino in my case). You can find the code here: http://www.scharnefski.de/smotsteu/smotsteu.htm („Zeit-Diagramm“).

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