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Accurate Calibration and Uncertainty Estimation of the Normal Spring Constant of Various AFM Cantilevers

Measurement of force on a micro- or nano-Newton scale is important when exploring the mechanical properties of materials in the biophysics and nanomechanical fields. The atomic force microscope (AFM) is widely used in microforce measurement. The cantilever probe works as an AFM force sensor, and the...

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Detalles Bibliográficos
Autores principales: Song, Yunpeng, Wu, Sen, Xu, Linyan, Fu, Xing
Formato: Online Artículo Texto
Lenguaje:English
Publicado: MDPI 2015
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4435172/
https://www.ncbi.nlm.nih.gov/pubmed/25763650
http://dx.doi.org/10.3390/s150305865
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author Song, Yunpeng
Wu, Sen
Xu, Linyan
Fu, Xing
author_facet Song, Yunpeng
Wu, Sen
Xu, Linyan
Fu, Xing
author_sort Song, Yunpeng
collection PubMed
description Measurement of force on a micro- or nano-Newton scale is important when exploring the mechanical properties of materials in the biophysics and nanomechanical fields. The atomic force microscope (AFM) is widely used in microforce measurement. The cantilever probe works as an AFM force sensor, and the spring constant of the cantilever is of great significance to the accuracy of the measurement results. This paper presents a normal spring constant calibration method with the combined use of an electromagnetic balance and a homemade AFM head. When the cantilever presses the balance, its deflection is detected through an optical lever integrated in the AFM head. Meanwhile, the corresponding bending force is recorded by the balance. Then the spring constant can be simply calculated using Hooke’s law. During the calibration, a feedback loop is applied to control the deflection of the cantilever. Errors that may affect the stability of the cantilever could be compensated rapidly. Five types of commercial cantilevers with different shapes, stiffness, and operating modes were chosen to evaluate the performance of our system. Based on the uncertainty analysis, the expanded relative standard uncertainties of the normal spring constant of most measured cantilevers are believed to be better than 2%.
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spelling pubmed-44351722015-05-19 Accurate Calibration and Uncertainty Estimation of the Normal Spring Constant of Various AFM Cantilevers Song, Yunpeng Wu, Sen Xu, Linyan Fu, Xing Sensors (Basel) Article Measurement of force on a micro- or nano-Newton scale is important when exploring the mechanical properties of materials in the biophysics and nanomechanical fields. The atomic force microscope (AFM) is widely used in microforce measurement. The cantilever probe works as an AFM force sensor, and the spring constant of the cantilever is of great significance to the accuracy of the measurement results. This paper presents a normal spring constant calibration method with the combined use of an electromagnetic balance and a homemade AFM head. When the cantilever presses the balance, its deflection is detected through an optical lever integrated in the AFM head. Meanwhile, the corresponding bending force is recorded by the balance. Then the spring constant can be simply calculated using Hooke’s law. During the calibration, a feedback loop is applied to control the deflection of the cantilever. Errors that may affect the stability of the cantilever could be compensated rapidly. Five types of commercial cantilevers with different shapes, stiffness, and operating modes were chosen to evaluate the performance of our system. Based on the uncertainty analysis, the expanded relative standard uncertainties of the normal spring constant of most measured cantilevers are believed to be better than 2%. MDPI 2015-03-10 /pmc/articles/PMC4435172/ /pubmed/25763650 http://dx.doi.org/10.3390/s150305865 Text en © 2015 by the authors; licensee MDPI, Basel, Switzerland. https://creativecommons.org/licenses/by/4.0/This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution license (http://creativecommons.org/licenses/by/4.0/ (https://creativecommons.org/licenses/by/4.0/) ).
spellingShingle Article
Song, Yunpeng
Wu, Sen
Xu, Linyan
Fu, Xing
Accurate Calibration and Uncertainty Estimation of the Normal Spring Constant of Various AFM Cantilevers
title Accurate Calibration and Uncertainty Estimation of the Normal Spring Constant of Various AFM Cantilevers
title_full Accurate Calibration and Uncertainty Estimation of the Normal Spring Constant of Various AFM Cantilevers
title_fullStr Accurate Calibration and Uncertainty Estimation of the Normal Spring Constant of Various AFM Cantilevers
title_full_unstemmed Accurate Calibration and Uncertainty Estimation of the Normal Spring Constant of Various AFM Cantilevers
title_short Accurate Calibration and Uncertainty Estimation of the Normal Spring Constant of Various AFM Cantilevers
title_sort accurate calibration and uncertainty estimation of the normal spring constant of various afm cantilevers
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4435172/
https://www.ncbi.nlm.nih.gov/pubmed/25763650
http://dx.doi.org/10.3390/s150305865
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