Stoppi built an atomic force microscope (AFM) out of junk parts, and got good results considering, with a 35-micron resolution across a printed circuit board (PCB) copper pour.
An AFM is a height-measuring instrument with very high resolution, making it ideal for measuring and imaging surface imperfections on a very fine scale.
Traditional AFMs use a piezo micromotor to move the sample up and down to a very fine point, with the height measured from the piezo setup and a motor stage.
Stoppi’s design replaced the piezo motor with a laser reflecting off a mirror onto a line sensor, a simpler solution that also allowed increasing the minimum resolvable height by moving the line sensors further away from the sample.
