Journal of Ultrafine Grained and Nanostructured  Materials

Journal of Ultrafine Grained and Nanostructured Materials

Effects of Fluid Environment Properties on the Nonlinear Vibrations of AFM Piezoelectric Microcantilevers

Document Type : Research Paper

Authors
1 Department of Mechanical Engineering, University of Guilan, Rasht, Iran.
2 Department of Engineering Science, Faculty of Technology and Engineering, East of Guilan, University of Guilan, Rudsar-Vajargah, Iran.
Abstract
Nowadays, atomic-force microscopy plays a significant role in nanoscience and nanotechnology, and is widely used for direct measurement at atomic scale and scanning the sample surfaces. In tapping mode, the microcantilever of atomic-force microscope is excited at resonance frequency. Therefore, it is important to study its resonance. Moreover, atomic-force microscopes can be operated in fluid environments such as their applications in chemical and biological sensors. Additionally, piezoelectric microcantilevers are used to enhance atomic-force microscope scanning. Motivated by these considerations, presented herein is a finite element investigation into the nonlinear vibration behavior of piezoelectric microcantilever of atomic-force microscopes in fluid environment. For this purpose, a 3D finite element model coupled with a computational fluid dynamics model is introduced based upon a fluid-solid interaction analysis. First, the reliability of present fluid-solid interaction analysis is revealed by comparison with experimental data available in the literature. Then, numerical results are presented to study the influences of fluid dynamic viscosity and density on the resonance frequency, resonance amplitude and time response of piezoelectric microcantilever. It was shown that increasing the fluid density and dynamic viscosity results in the decrease of resonance frequency. For example, for density equal to 1000 kg/m3 , increasing the viscosity of fluid environment from 0.1 to 1, 10 and 20 mPa.s leads to decrease of resonance frequency about 3%, 29% and 42%, respectively. Also, the resonance amplitude of microcantilever increases as the density increases, while increasing dynamic viscosity has a decreasing effect on the resonance amplitude.
Keywords

14. Salehi, Mi., Marashi, P., Salehi, Ma., and Ghannad, R., 2014, “Optimization of the FeCo nanowire fabrication embedded in anodic aluminum oxide template by response surface methodology,” J. Ultrafine Grained Nanostruct. Mater., 47, pp. 27-35.
 
Volume 50, Issue 2
December 2017
Pages 117-123

  • Receive Date 10 June 2017
  • Revise Date 01 November 2017
  • Accept Date 24 November 2017