Creating a Low-Cost Scanning Tunneling Microscope

Commercial Scanning Tunneling Microscopes (STMs), which typically cost upwards of $10,000, is used in analyzing the atomic structure of conductive materials. This project is aimed at producing a low-cost and accurate STM for under $500 that can be purchased as a kit and recreated by following a tutorial. Commercial STMs use piezoelectric actuators for the X, Y, and Z movement of the tip. In order to reduce cost dramatically, we have developed a mechanism to control the X and Y movement using a novel magnetic actuation system that is significantly more cost-effective than piezoelectric actuators. In addition, the usage of magnetic actuation provides a promising means for measurement scale flexibility due to the easy adjustment of the compliance of the system. The major difficulties of the project are due primarily to the cost constraint, such as achieving a repeatable close approach to successful tunneling without using high-end components and also being able to suppress noise, both electrical and mechanical, to make precise measurements. This implies replicability of the design of the apparatus without using specialized equipment that would pose additional expenses. Regardless, the ability for creating low-cost scanning tunneling microscope remains feasible accounting for research, development and material costs. While internal noise still poses problems, effective noise reduction from the environment have been proved successful and the ability to approach a tunneling current has become more reliable. Software licensing for the apparatus will reduce its pricing as it is created from the ground up through the use of LabVIEW software.