There are lots of electronic projects that can be made at home but I would have never thought I would see a Scanning Electron Microscope that was made at home! The results are able to be watched on an oscilloscope. The comments of the article are great also and worth a read. You can see the system in operation in the video at 9:53.
Via: Make
“The lock washer is only being magnified 10 or 20x. In this test video, I wasn’t too concerned with focus, so the resolution is probably 50um or more. Eventually, I hope to achieve resolution of about 1um. I will probably experiment with different objective lens placement, final aperture size (currently 100um), deflection plate placement, etc.
I originally wanted to use a microprocessor to generate the raster scan pattern and capture the data for storage/display on an LCD. I may still do this, but there are a few problems: finding a microprocessor with enough RAM to store the image matrix, using a DAC to generate the raster scan pattern at live video rates, and interfacing with a nice LCD (ie generate SVGA video). The Parallax Propeller seems like it might work, but needs a lot of development.”