Piezoelectric bimorph-based translation device for two-dimensional, remote micropositioning

Abstract

We describe a two-dimensional, remote micropositioning device that uses the bending mode of a piezoelectric bimorph for walking in the forward/reverse direction of motion. For this mode of operation step sizes range from ∼50 to 5000 nm, with a voltage sensitivity of ∼10 nm/V. Speeds of about 1 mm/s are possible. In the lateral direction of motion, the linear extension mode of the bimorph is used, giving step sizes from ∼50 to 1000 nm, with a sensitivity of ∼2 nm/V. For the walking sequence, anodized aluminum feet are electrostatically clamped to an anodized aluminum baseplate. When used as the coarse positioner in a scanning tunneling microscope, the device requires less than 100 V operating voltage, thus eliminating the high-voltage supply needed for previous piezoelectric walking devices. A circuit diagram for ‘‘joystick’’ control of the micropositioner is also described.