A simple and efficient quasi 3-dimensional viscoelastic model and software for simulation of tapping-mode atomic...

Area of Science:

• Materials Science
• Nanotechnology
• Computational Physics

Background:

• Viscoelasticity is crucial in atomic force microscopy (AFM) for understanding material properties at the nanoscale.
• Standard linear solid (SLS) models describe fundamental viscoelastic behaviors like stress relaxation and creep.
• Existing 1D SLS models in AFM simulations lack accurate repulsive force curve curvature, limiting quantitative analysis.

Purpose of the Study:

• Introduce a quasi-3-dimensional (Q3D) viscoelastic model for enhanced AFM simulations.
• Improve the quantitative interpretation of AFM experimental data.
• Develop a computational tool for simulating AFM amplitude and phase spectroscopy.

Main Methods:

• Developed a Q3D viscoelastic model using a 2D array of standard linear solid (SLS) elements.
• Implemented the model in a software tool for AFM simulations.
• Simulated force curves for single- and multifrequency tapping-mode imaging.

Main Results:

• The Q3D model generates force curves with correct upward curvature in the repulsive region.
• The model maintains low computational cost, similar to 1D models.
• Simulations accurately reproduced expected features for tapping-mode imaging.
• The software tool can simulate amplitude and phase spectroscopy curves.

Conclusions:

• The Q3D viscoelastic model provides a significant advancement for AFM simulations.
• The model enables more accurate quantitative interpretation of AFM experimental data.
• The accompanying software tool aids in analyzing AFM measurements and can be adapted for various control schemes.