Single-tube three-dimensional scanner for scanning tunneling microscopy

We report a new type of three-dimensional mechanical scanner fabricated from a single piezoelectric tube. It has a typical response of 5 nm/V in each orthogonal direction and mechanical resonances at 8 kHz (bending perpendicular to the tube axis) and 40 kHz (motion parallel to the tube axis). When used in a scanning tunneling microscope it is the higher frequency mode which is most critical since it corresponds to motion perpendicular to the sample surface. We show an image of the atomic surface of graphite taken in air using a tube scanner incorporated into a scanning tunneling microscope. The tube scanner allows the development of smaller, simpler, and faster scanning tunneling microscopes.