The goal was to build a scanning probe microscope using a piezoelectric buzzer split into 4 piezos to create a nanometer precise xyz stage. See this page for the basic concept.
Because I didn't have time to build the entire system with a coarse stage, tunneling current amplifier, feedback, etc, I mounted a mirror and a laser pointer to see the deflection of the buzzer.
Based on rough measurements of the laser deflection, I calculated the motion/voltage of the stage. Assuming a 1cm arm mounting a probe, the probe would deflect roughly 1 micron/volt. Assuming the z deflection is roughly the same, this would be too coarse for an STM, but ok for an AFM or other probes not requiring such a fine z resolution.