Accurate noncontact calibration of colloidal probe sensitivities in atomic force microscopy

Journal Article · Mon Jun 15 04:00:00 EDT 2009 · Review of Scientific Instruments

DOI:https://doi.org/10.1063/1.3152335· OSTI ID:22053592

Chung, Koo-Hyun; Shaw, Gordon A; Pratt, Jon R ^[1]

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1. National Institute of Standards and Technology, Gaithersburg, Maryland 20899 (United States)

The absolute force sensitivities of colloidal probes comprised of atomic force microscope, or AFM, cantilevers with microspheres attached to their distal ends are measured. The force sensitivities are calibrated through reference to accurate electrostatic forces, the realizations of which are described in detail. Furthermore, the absolute accuracy of a common AFM force calibration scheme, known as the thermal noise method, is evaluated. It is demonstrated that the thermal noise method can be applied with great success to colloidal probe calibration in air and in liquid to yield force measurements with relative standard uncertainties below 5%. Techniques to combine the electrostatics-based determination of the AFM force sensitivity with measurements of the colloidal probe's thermal noise spectrum to compute noncontact estimates of the displacement sensitivity and spring constant are also developed.

• OSTI ID: 22053592
• Journal Information: Review of Scientific Instruments, Journal Name: Review of Scientific Instruments Journal Issue: 6 Vol. 80; ISSN 0034-6748; ISSN RSINAK
• Country of Publication: United States
• Language: English

Related Subjects

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ACCURACY
AIR
ATOMIC FORCE MICROSCOPY
CALIBRATION
COLLOIDS
ELECTROSTATICS
LIQUIDS
MICROSPHERES
PROBES
SENSITIVITY
SPECTRA
TEMPERATURE NOISE