A Fully Computerized Scanning Tunnelling Microscope

A new, fully computerized and inexpensive, scanning tunnelling microscope was designed and built. Its key design feature is the application of the high sensitivity bimorph, for the coarse positioning of the bimorph is > 0.03 mm and can be divided up to the 12 bit number of steps. The bimorph positioning implies that this microscope is fully computer controlled, and using of bimorph instead of inch-worm implies low cost of the unit. The microscope can create images of the surface in the constant current mode and in the imaging current mode. The presented microscope works with the z-axis analog or digital feedback loop optionally. All parameters of the analog and digital feedback loop are computer controlled. Due to the digital z-axis feedback loop benefits, electron tunneling spectroscopy mode is naturally accessible. The performance of the microscope was tested in air by imaging of surface of HOPG (high oriented pyrolytic graphite).