A bimorph-driven inertial micropositioner for scanning tunnelling microscopy

A bimorph-based inertial linear slider motor, suitable for the coarse approach of the scanning tunnelling microscope tip to the sample, is described. It is best suited for moving micropositioning structures of low height such as bimorph parallelograms, in the z direction, but also for sample stages carrying small samples. It is operated either by trains of voltage pulses of asymmetric shapes, produced by a digital-to-analogue converter, or, since it can also be moved by suitable combinations of binary ones and zeros, simply by switching between two voltage levels. The second case resulted in the most efficient horizontal movement, but it was less successful in moving against gravity.