Dynamic simulation of atomic force microscope cantilevers oscillating in liquid

Michael James Martin, Hosam K. Fathy, Brian H. Houston

Research output: Contribution to journalArticlepeer-review

22 Scopus citations

Abstract

To simulate the behavior of an atomic force microscope (AFM) operating in liquid, a lumped-parameter model of a 40×5 μ m2 thick silicon cantilever with natural frequencies ranging from 3.0 to 6.0× 105 rad/s was combined with a transient Navier-Stokes solver. The equations of motion were solved simultaneously with the time-dependent flow field. The simulations successfully capture known characteristics of the AFM in liquid, including large viscous losses, reduced peak resonant frequencies, and frequency-dependent damping. From these simulations, the transfer function G (s) of the system was obtained. While the transfer function shares many of the characteristics of a second-order system at higher frequencies, the frequency-dependent damping means that a second-order model cannot be applied. The viscous damping of the system is investigated in greater depth. A phase difference between the peak velocity and peak damping force is observed. Both the phase difference and the magnitude of the damping are shown to be functions of the excitation frequency. Finally, the damping is shown to be strongly dependent on the liquid viscosity and weakly dependent on the liquid density.

Original languageEnglish (US)
Article number044316
JournalJournal of Applied Physics
Volume104
Issue number4
DOIs
StatePublished - 2008

All Science Journal Classification (ASJC) codes

  • Physics and Astronomy(all)

Fingerprint Dive into the research topics of 'Dynamic simulation of atomic force microscope cantilevers oscillating in liquid'. Together they form a unique fingerprint.

Cite this