Design and Construction of a Cost Effective Computer Controlled Scanning Tunneling Microscope and Probe Production Technique

Dr. M Ahmadi; Ahad Ahmadzade

Volume : IV, Issue : VIII, August - 2014

Design and Construction of a Cost Effective Computer Controlled Scanning Tunneling Microscope and Probe Production Technique

Dr. M Ahmadi, Ahad Ahmadzade

Abstract :

Working in the field of Nano technology requires instruments that can visualize and manipulate nanostructures. A Scanning Tunneling Microscope (STM) can analyze a sample surface at nano&ndash;scale and produce its topographical image. The design of the STM is based on Screw&ndash;Lever Motion demagnifier described in the literature. The scanner uses three orthogonal stack piezo cubes joined together with a metallic tripod. Images of highly oriented pyrolytic graphite have been obtained in air with constant current mode. The atomic resolution images obtained clearly show the hexagonal lattice of graphite. In this article, we describe design and construction of a robust low cost computer controlled constant current imaging STM. We also explain a simple method used to produce probes (tips) for the microscope. Major sections such as viation isolation system, scan unit, analogue and computer control electronics have all been described. Data acquisition system designed and built is very low cost and easily available to everyone. The software that controls the system was written in Delphi language. To achieve cost effectiveness, expensive components and royalty controlled software have been avoided. The STM designed is therefore low cost, efficient and suitable for students, researchers and low budget institutions.