Low-voltage and high-performance buzzer-scanner based streamlined atomic force microscope system

• Published in: Nanotechnology 2013-11, Vol.24 (45), p.455503-455503
• Main Authors: Wang, Wei-Min, Huang, Kuang-Yuh, Huang, Hsuan-Fu, Hwang, Ing-Shouh, Hwu, En-Te
• Format: Article
• Language: English
• Subjects: Actuation; Condensed matter: structure, mechanical and thermal properties; Electron, ion, and scanning probe microscopy; Exact sciences and technology; Physics; Scanning probe microscopy: scanning tunneling, atomic force, scanning optical, magnetic force, etc; Structure of solids and liquids; crystallography
• ISSN: 0957-4484; 1361-6528
• DOI: 10.1088/0957-4484/24/45/455503

In this paper we present a novel scanner design in a quad-rod actuation structure, actuated by piezoelectric disk buzzers, and a new type of atomic force microscope (AFM), which uses this buzzer-scanner and a compact disk/digital-versatile-disk astigmatic optical pickup unit (OPU) for the detection of cantilever movements. Commercially available piezoelectric disk buzzers have a low capacitance and can be driven by low-voltage signal sources, such as analog outputs from a data acquisition card, without additional voltage or current amplifiers. Various scanning ranges can be realized through changing the dimensions of the actuation structure and/or the choice of disk buzzer. We constructed a buzzer-scanner and evaluated its performance. The scanner had a scanning range of 15 μm in the X and Y directions and an actuation range of 3.5 μm on the Z axis, with nonlinearity of 2.11%, 2.73%, and 2.19% for the X,Y and Z axes, respectively. The scanner had a resonance frequency of approximately 360 Hz on the X and Y axes, and 4.12 kHz on the Z axis. An OPU-AFM with this buzzer-scanner can resolve single atomic steps of a graphite substrate with a noise level of 0.06 nm. The obtained topographic images exhibit much less distortion than those obtained with an AFM using a piezoelectric tube scanner.