### Session H2: Poster Session (3:30 - 5:15 PM)

3:30 PM–3:30 PM, Friday, November 13, 2009
IMU Room: 243 (Ballroom)

Abstract ID: BAPS.2009.PSF.H2.29

### Abstract: H2.00029 : Construction of an Inexpensive Scanning Tunneling Microscope for Undergraduate Laboratories

MathJax On | Off     Abstract

#### Authors:

Paul Garcia
(Doane College)

Justin Nitz
Our goal is to produce an inexpensive, room-temperature, atmospheric-pressure scanning tunneling microscope (STM) with atomic resolution. Our prototype uses slip-stick motion for coarse approach to the surface to be imaged. Motion of the tip is accomplished with four flat piezoelectric translators that provide both z-motion (slip-stick and feedback control) as well as the x-y scanning motion. Maximum x-y scan range is estimated and measured to be approximately 1.7 $\mu$m x 1.7 $\mu$m and the fine z-motion range is estimated to be about 570 nm. Control of the x-y motion is done with a microcontroller containing two 16-bit DACs (digital to analog converter). The z-motion is driven by an analog loop that amplifies the tunneling current and then drives the inner electrode of the piezo translators. The cost of our prototype is currently under {\\$}300 and we hope to keep it very affordable for high school and college teaching laboratories.