Quantitative characterization of surface topography using spectral analysis

TL;DR

This paper reviews methods for accurately reconstructing the power spectral density of surface topography from measurements, enabling better prediction and tuning of surface functional properties like adhesion and friction.

Contribution

It provides a comprehensive overview of PSD mathematical definitions, reconstruction strategies, artifact mitigation, and bounds estimation, emphasizing the importance of accurate PSD analysis for surface property prediction.

Findings

Reconstruction strategies improve PSD accuracy across scales

Artifact detection enhances measurement reliability

Analytical models enable property tuning via surface topography

Abstract

Roughness determines many functional properties of surfaces, such as adhesion, friction, and (thermal and electrical) contact conductance. Recent analytical models and simulations enable quantitative prediction of these properties from knowledge of the power spectral density (PSD) of the surface topography. The utility of the PSD is that it contains statistical information that is unbiased by the particular scan size and pixel resolution chosen by the researcher. In this article, we first review the mathematical definition of the PSD, including the one- and two-dimensional cases, and common variations of each. We then discuss strategies for reconstructing an accurate PSD of a surface using topography measurements at different size scales. Finally, we discuss detecting and mitigating artifacts at the smallest scales, and computing upper/lower bounds on functional properties obtained from models. We accompany our discussion with virtual measurements on computer-generated surfaces. This discussion summarizes how to analyze topography measurements to reconstruct a reliable PSD. Analytical models demonstrate the potential for tuning functional properties by rationally tailoring surface topography - however, this potential can only be achieved through the accurate, quantitative reconstruction of the power spectral density of real-world surfaces.