Microscópio de tunelamento por varredura: STM

Abstract

Nanotechnology has the potential to be responsible for the next great technological revolution, since it acts in different areas of knowledge. According to Agência Brasil, the Brazilian market for products based on nanotechnologies originally developed in the country last year totaled about $115 million, placing Brazil as responsible for 0.03% of the world of nanotechnology (AGÊNCIA BRASIL 2011). This project aims to develop a scanning tunneling microscope at low cost. The methodology applied to the project is the classic model by following these steps: research, design, implementation and testing, in which hardware is a critical part. During its course, the methodology included a process of documenting the steps and decisions in order to allow the use and reuse of expertise acquired in subsequent scientific projects. The microscope is composed of four main modules: the module that allows the tunneling current’s detection, the surface scanning module, the discretization and pre-processing module, and the processing and imaging one. This system can perform a scan with a probe on the surface to be analyzed, which is held concurrently by detecting the current generated by tunnel effect between the surface and probe. The control system is responsible for scanning and correcting the probe height. The microcontroller collects and digitizes the position information (XY) and the probe’s height, and sends that data to the computer, where there is software that generates images from the data obtained. The final goal of this project is a system that has hardware, firmware and software specific to that application, with commercial value about 50% cheaper than similar to some equipment found in Europe. Another result to UTFPR was the first steps in order to enable some nanotechnology research to take place at the university.