On eigenmodes, stiffness, and sensitivity of atomic force microscope cantilevers in air versus liquids

Journal Article · Mon Feb 15 00:00:00 EST 2010 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.3284206· OSTI ID:21480226

Kiracofe, Daniel; Raman, Arvind ^[1]

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1. Birck Nanotechnology Center and School of Mechanical Engineering, Purdue University, West Lafayette, Indiana 47904-2088 (United States)

The effect of hydrodynamic loading on the eigenmode shapes, modal stiffnesses, and optical lever sensitivities of atomic force microscope (AFM) microcantilevers is investigated by measuring the vibrations of such microcantilevers in air and water using a scanning laser Doppler vibrometer. It is found that for rectangular tipless microcantilevers, the measured fundamental and higher eigenmodes and their equivalent stiffnesses are nearly identical in air and in water. However, for microcantilevers with a tip mass or for picket shaped cantilevers, there is a marked difference in the second (and higher) eigenmode shapes between air and water that leads to a large decrease in their modal stiffness in water as compared to air as well as a decrease in their optical lever sensitivity. These results are explained in terms of hydrodynamic interactions of microcantilevers with nonuniform mass distribution. The results clearly demonstrate that tip mass and hydrodynamic loading must be taken into account in stiffness calibration and optical lever sensitivity calibration while using higher-order eigenmodes in dynamic AFM.

• OSTI ID: 21480226
• Journal Information: Journal of Applied Physics, Vol. 107, Issue 3; Other Information: DOI: 10.1063/1.3284206; (c) 2010 American Institute of Physics; ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
AIR
ATOMIC FORCE MICROSCOPY
CALIBRATION
FLEXIBILITY
HYDRODYNAMICS
LIQUIDS
MASS DISTRIBUTION
MECHANICAL VIBRATIONS
SENSITIVITY
WATER
DISTRIBUTION
FLUID MECHANICS
FLUIDS
GASES
HYDROGEN COMPOUNDS
MECHANICAL PROPERTIES
MECHANICS
MICROSCOPY
OXYGEN COMPOUNDS
SPATIAL DISTRIBUTION
TENSILE PROPERTIES