Just a pointer to the article the high schoolers used to make an STM the size of a breadbox:
A miniaturized scanning tunneling microscope with large operation range, Rev.Sci.Instrum. 64 (3), March 1993, pp.692-693.
This is an STM that could be built with a total volume including control electronics of ONE square inch. It's two concentric piezo tubes,both 0.5 inches long, with outer tube diameter 0.25 inch, and inner tube diameter 0.09 inch (might have to go with 0.125 inch, Stavely apparently doesn't make an 0.09 inch diameter tube). A glass tube is glued inside the inner tube, and a wire is pushed inside the tube. Basically, you set a sample on top of a tube. To move the sample, you apply a sawtooth-shaped voltage (i.e., slowly increasing, then rapidly droping off) to one side of the tube. It slowly bends in one direction, with the sample moving along with it. Then, the current rapidly drops off, and the tube rapidly (10,000 g's acceleration) returns to it's resting position. The sample remains where it is due to it's inertia. Thus the sample's postion on top of the tube has changed. A series of these sawtooth voltages steps the sample laterally anywhere you want it to go- and does it VERY rapidly: 100,000 pixels/sec. Same principle with the scanning tip. It's moved up and down via slow expansion or contraction, and rapid return. So you have an STM with NO moving parts. And NO need for vibration isolation- the harmonic is extremely high due to smallness and rigid construction: 100 kHz. And you mount the sample by placing it on top of a tube. Simplicity itself.
Having read the previous pararaph, a few clarifying comments are in order. The outer tube, the one the sample sits on, moves the sample laterally anywhere you want it to go. The inner tube holds the wire and sharpened tip, and through piezo expansion and contraction moves the probe first near to the sample, then keeps it close using the tunneling current as feedback as the sample moves back and forth above it.
THIS is the design for homebrew STMers!
Jim Rice