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Thermal Noise Reduction of Mechanical Oscillators by Actively Controlled External Dissipative ForcesWe show that the thermal fluctuations of very soft mechanical oscillators, such as the cantilever in an atomic force microscope (AFM), can be reduced without changing the stiffness of the spring or having to lower the environment temperature. We derive a theoretical relationship between the thermal fluctuations of an oscillator and an actively external-dissipative force. This relationship is verified by experiments with an AFM cantilever where the external active force is coupled through a magnetic field. With simple instrumentation, we have reduced the thermal noise amplitude of the cantilever by a factor of 3.4, achieving an apparent temperature of 25 K with the environment at 295K. This active noise reduction approach can significantly improve the accuracy of static position or static force measurements in a number of practical applications.
Document ID
20010002835
Acquisition Source
Headquarters
Document Type
Reprint (Version printed in journal)
Authors
Liang, Shoudan
(NASA Ames Research Center Moffett Field, CA United States)
Medich, David
(Virginia Univ. Charlottesville, VA United States)
Czajkowsky, Daniel M.
(Virginia Univ. Charlottesville, VA United States)
Sheng, Sitong
(Virginia Univ. Charlottesville, VA United States)
Yuan, Jian-Yang
(Alberta Research Council Edmonton, Alberta Canada)
Shao, Zhifeng
(Virginia Univ. Charlottesville, VA United States)
Date Acquired
August 20, 2013
Publication Date
January 1, 1999
Publication Information
Publication: Ultramicroscopy
Publisher: Elsevier Science B.V.
ISSN: 0304-3991
Subject Category
Instrumentation And Photography
Distribution Limits
Public
Copyright
Other

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