Characterization of polyester degradation using tapping mode atomic force microscopy: exposure to alkaline solution at room temperature

2001 ◽  
Vol 74 (1) ◽  
pp. 139-149 ◽  
Author(s):  
X Gu ◽  
D Raghavan ◽  
T Nguyen ◽  
M.R VanLandingham ◽  
D Yebassa
Author(s):  
Xiaopeng Zhao ◽  
Harry Dankowicz

Tapping-mode atomic force microscopy has wide applications for probing the nanoscale surface and subsurface properties of numerous materials in a variety of environments. Strongly nonlinear effects due to large variations in the force field on the probe tip over very small length scales and the intermittency of contact with the sample, however, result in strong dynamical instabilities. These can result in a sudden loss of stability of low-contact-velocity oscillations of the atomic-force-microscope tip in favor of oscillations with high contact velocity, coexistence of stable oscillatory motions, and destructive, nonrepeatable, and unreliable characterization of the nanostructure. In this paper, dynamical systems tools for piecewise smooth systems are employed to characterize the loss of stability and associated parameter hysteresis phenomena.


Author(s):  
Harry Dankowicz

Tapping-mode atomic force microscopy provides a means for successful and non-intrusive characterization of soft physical and biological structures at the nanoscale. Its full potential can only be realized, provided that the response of the oscillating probe tip to the strongly nonlinear, near-field force interactions with the structure and the intermittency of contact can be accurately modelled, analysed, controlled and interpreted. To this end, this paper reviews some experimental observations of fundamentally nonlinear behaviour of the tip dynamics. It discusses the nonlinear phenomenology that explains their presence in the tapping-mode operation of the atomic force microscope. Particular emphasis is placed on the coexistence of different steady-state responses and their origin in transitions across regions of rapidly varying force characteristics. The heuristics of a recently developed method for treating such transitions are presented and insights into its implications are drawn from related micro- and nanoscale applications.


2005 ◽  
Vol 1 (2) ◽  
pp. 109-115 ◽  
Author(s):  
Xiaopeng Zhao ◽  
Harry Dankowicz

Tapping-mode atomic force microscopy has wide applications for probing the nanoscale surface and subsurface properties of a variety of materials in a variety of environments. Strongly nonlinear effects due to large variations in the force field on the probe tip over very small length scales and the intermittency of contact with the sample, however, result in strong dynamical instabilities. These can result in a sudden loss of stability of low-contact-velocity oscillations of the atomic-force-microscope tip in favor of oscillations with high contact velocity, coexistence of stable oscillatory motions, and destructive, nonrepeatable, and unreliable characterization of the nanostructure. In this paper, dynamical systems tools for piecewise-smooth systems are employed to characterize the loss of stability and associated parameter-hysteresis phenomena.


Sign in / Sign up

Export Citation Format

Share Document