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Title: Nondestructive and noncontact method for determining the spring constant of rectangular cantilevers

Journal Article · · Review of Scientific Instruments
DOI:https://doi.org/10.1063/1.2720727· OSTI ID:20953427
; ; ;  [1]
  1. Max Planck Institute for Polymer Research, Ackermannweg 10, 55128 Mainz (Germany)

We present here an experimental setup and suggest an extension to the long existing added-mass method for the calibration of the spring constant of atomic force microscope cantilevers. Instead of measuring the resonance frequency shift that results from attaching particles of known masses to the end of cantilevers, we load them with water microdrops generated by a commercial inkjet dispenser. Such a device is capable of generating drops, and thus masses, of extremely reproducible size. This makes it an ideal tool for calibration tasks. Moreover, the major advantage of water microdrops is that they allow for a nearly contactless calibration: no mechanical micromanipulation of particles on cantilevers is required, neither for their deposition nor for removal. After some seconds the water drop is completely evaporated, and no residues are left on the cantilever surface or tip. We present two variants: we vary the size of the drops and deposit them at the free end of the cantilever, or we keep the size of the drops constant and vary their position along the cantilever. For the second variant, we implemented also numerical simulations. Spring constants measured by this method are comparable to results obtained by the thermal noise method, as we demonstrate for six different cantilevers.

OSTI ID:
20953427
Journal Information:
Review of Scientific Instruments, Vol. 78, Issue 4; Other Information: DOI: 10.1063/1.2720727; (c) 2007 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 0034-6748
Country of Publication:
United States
Language:
English