On modeling and measuring viscoelasticity with dynamic Atomic Force Microscopy
Abstract
The interaction between a rapidly oscillating atomic force microscope tip and a soft material surface is described using both elastic and viscous forces with a moving surface model. We derive the simplest form of this model, motivating it as a way to capture the impact dynamics of the tip and sample with an interaction consisting of two components: interfacial or surface force, and bulk or volumetric force. Analytic solutions to the piece-wise linear model identify characteristic time constants, providing a physical explanation of the hysteresis observed in the measured dynamic force quadrature curves. Numerical simulation is used to fit the model to experimental data and excellent agreement is found with a variety of different samples. The model parameters form a dimensionless impact-rheology factor, giving a quantitative physical number to characterize a viscoelastic surface that does not depend on the tip shape or cantilever frequency.
Cite
@article{arxiv.1711.09024,
title = {On modeling and measuring viscoelasticity with dynamic Atomic Force Microscopy},
author = {Per-Anders Thorén and Riccardo Borgani and Daniel Forchheimer and Illia Dobryden and Per M. Claesson and Hailu G. Kassa and Philippe Leclère and Yifan Wang and Heinrich M. Jaeger and David B. Haviland},
journal= {arXiv preprint arXiv:1711.09024},
year = {2018}
}
Comments
13 pages, 7 figures