I recently finished building a scanning tunneling microscope as a hobby project. The inspiration for this project came mainly from seeing John Alexander’s simple STM project some time ago. I’m a physics PhD student and although I work mainly with optical microscopes, I’ve had a few opportunities to use an atomic force microscope (AFM) and thought that building one would be a fun project. I ended up building an STM as it’s somewhat simpler and easily capable of atomic resolution imaging, but I do plan to add AFM capabilities to it at some point.
My STM uses the unimorph disk scanner invented by John Alexander. This type of scanner is much more sensitive and less rigid than the (much more expensive) piezo tube scanners typically used in scanning probe microscopes, but with low enough scanning voltages and decent vibration isolation I was able to achieve atomic resolution on graphite!
I’m currently working on improved schematics and laying out a PCB for this project, as the electronics are mostly on a breadboard at the moment.