Adaptive Speckle Imaging Interferometry: a new technique for the analysis of microstructure dynamics, drying processes and coating formation

TL;DR

Adaptive Speckle Imaging Interferometry (ASII) is a novel, high-dynamic-range technique for non-invasive analysis of microstructure dynamics during drying and coating formation, enabling real-time monitoring with a new commercial instrument.

Contribution

This paper introduces ASII, an innovative extension of diffusing wave spectroscopy, with an efficient inter-image distance tool and speckle rate concept for dynamic analysis.

Findings

Effective non-invasive characterization of drying phenomena.

High dynamic range and reactive monitoring capability.

Commercial instrument HORUS(R) developed for practical applications.

Abstract

We describe an extension of multi-speckle diffusing wave spectroscopy adapted to follow the non-stationary microscopic dynamics in drying films and coatings in a very reactive way and with a high dynamic range. We call this technique "Adaptive Speckle Imaging Interferometry". We introduce an efficient tool, the inter-image distance, to evaluate the speckle dynamics, and the concept of "speckle rate" (SR, in Hz) to quantify this dynamics. The adaptive algorithm plots a simple kinetics, the time evolution of the SR, providing a non-invasive characterization of drying phenomena. A new commercial instrument, called HORUS(R), based on ASII and specialized in the analysis of film formation and drying processes is presented.