DOI
https://doi.org/10.25772/B7QQ-HG45
Defense Date
2010
Document Type
Thesis
Degree Name
Master of Science
Department
Mechanical and Nuclear Engineering
First Advisor
Kam Leang
Abstract
An iterative control algorithm (ICA) which uses an approximate inverse-hysteresis model is implemented to compensate for hysteresis to precisely fabricate features on a soft polymer substrate using an atomic force microscope (AFM). The AFM is an important instrument in micro/nanotechnology because of its ability to interrogate, manipulate, and fabricate objects at the micro/nanoscale. The AFM uses a piezoelectric actuator to position an AFM-probe tip relative to the sample surface in three dimensions. In particular, precision lateral control of the AFM-probe tip relative to the sample surface is needed to ensure high-performance operation of the AFM. However, precision lateral positioning of the AFM-probe tip is challenging due to significant positioning error caused by hysteresis effect. An ICA which incorporates an approximate inverse of the hysteresis behavior is proposed to compensate for the hysteresis-caused positioning error. The approach is applied to fabricate a feature using the AFM on a polycarbonate surface, and it is demonstrated that the maximum tracking error can be reduced to 0.225% of the displacement range, underscoring the benefits of the control method.
Rights
© The Author
Is Part Of
VCU University Archives
Is Part Of
VCU Theses and Dissertations
Date of Submission
November 2010