Several homegrown recipes abound for building scanning tunneling electron microscopes. One such project, from a research group at the University of Muenster in Germany, is called the SXM; through their website, you can buy a construction kit for 985 euros. But many of these projects, designed by academics, rely on pricey external hardware -- like signal generators and oscilloscopes -- that the average person might not have. They also don't always use the most up-to-date technology, and while some have released schematics, none of them are open source. De'Angeli's project is designed to stand alone, and it is entirely open source, relying on the Arduino, the popular open-source microcontroller board, which is in active use for thousands of projects around the globe. A Python script takes the raw data and pulls it into an image file. D'Angeli's hope is that average folks -- people not affiliated with science departments at all -- will start making and using their own STMs at home.