Sponsor
Portland State University. Department of Physics
First Advisor
Andres La Rosa
Date of Publication
Spring 1-1-2012
Document Type
Thesis
Degree Name
Master of Science (M.S.) in Applied Physics
Department
Physics
Language
English
Subjects
Scanning probe microscopy, Acoustic imaging, Feedback control systems, Nanofluidics, Nanotechnology, Nanotribology
DOI
10.15760/etd.548
Physical Description
1 online resource (xv, 102 p.)
Abstract
A remote-sensing acoustic method for implementing position control feedback in Scanning Probe Microscopy (SPM) is presented. The capabilities of this feedback control using the new Whispering Gallery Acoustic Sensing (WGAS) method is demonstrated in a Shear-force Scanning Probe Microscope that uses a sharp probe attached to a piezoelectric Quartz Tuning Fork (QTF) firmly mounted on the microscope's frame. As the QTF is electrically driven its mechanical response reaches the SPM frame which then acts as a resonant cavity producing acoustic modes measured with an acoustic sensor strategically placed on the SPM head. The novelty of the WGAS resides in using an SPM frame with a perimeter closely matching the intervening acoustic wavelength to act as a resonant cavity. The whispering gallery cavity constitutes an acoustic amplifier for the mechanical motion of the QTF probe. The observed monotonic behavior of the whispering gallery acoustic signal as a function of the probe sample distance is exploited here for tip-sample distance control with nanometer sensitivity, thus allowing topographic characterization as the probe is scanned across the sample's surface. This thesis includes a description of a Labview based programming for the Field Programmable Gate Array (FPGA) card used in the automated control of the WGAS feedback microscope, a solution for improving the effective resolution of the Digital to Analog Converter (DAC) and initial results towards theoretically modeling the WGAS working principle.
Rights
In Copyright. URI: http://rightsstatements.org/vocab/InC/1.0/ This Item is protected by copyright and/or related rights. You are free to use this Item in any way that is permitted by the copyright and related rights legislation that applies to your use. For other uses you need to obtain permission from the rights-holder(s).
Persistent Identifier
http://archives.pdx.edu/ds/psu/8468
Recommended Citation
Fernandez Rodriguez, Rodolfo, "Development and Implementation of Acoustic Feedback Control for Scanning Probe Microscopy" (2012). Dissertations and Theses. Paper 548.
https://doi.org/10.15760/etd.548
Included in
Atomic, Molecular and Optical Physics Commons, Diagnosis Commons, Medical Biophysics Commons
Comments
Portland State University. Dept. of Physics