I’m a do-it-yourselfer kind of guy.  Building something is so much more satisfying than buying it, and I’ve always enjoyed understanding how things work under the hood.  And I’m cheaper than Scrooge.

scanning tunneling microscope.

For the non-physicists out there, basically an STM works like an arc welder. You put a probe very close to a surface, and electrons jump across the gap like a quantum mechanical spark. Since electrons are moving across the gap, there is a current flowing through the probe which can be measured. The size of this current tells you what the surface “looks like” to an electron.

At first a homemade STM sounded kind of ridiculous. STMs require a probe with a tip sharpened to a few atoms that can be positioned with accuracy better than a tenth of a nanometer. The current flowing between the tip and the surface is in the nanoAmpere range. That’s really small. But then I realized that this technology is over twenty years old. Physics departments build these things from scratch all the time. Really, it’s not that hard. By leaving out the vaccuum chamber and sacrificing some accuracy, this is doable.

A group in Germany has plans for a simple STM online. They also sell all the stuff you need for around $1100. Unfortunately, I have a budget of about $10 and a stick of gum, so I’ll have to improvise a bit. Expect updates on my progress.

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