Ewoldt paper named best publication by Journal of Rheology

A paper published last year by MechSE Associate Professor Randy Ewoldt and colleagues has won the Journal of Rheology 2021 Publication Award.

The Society of Rheology annually selects the best paper published in the Journal of Rheology during the preceding two years for special recognition at the annual meeting and for a monetary award. The award will be presented in October 2021 at the 92nd Society of Rheology Annual Meeting in Bangor, Maine.

In their paper, “Operating windows for oscillatory interfacial shear rheology,” authors Damian Renggli, Alexandra A. Alicke, Ewoldt, and Jan Vermant discuss recent advances in the ability to measure interfacial viscoelasticity and clarify these discoveries in terms of the ranges of interfacial complex modulus as functions of interfacial stress and strain amplitudes that can be reliably measured. Interfacial rheometry measurements are challenging for various reasons that are understood by rheology experts. However, scientists had not previously studied the operating limits of interfacial rheometers; this work from Ewoldt and colleagues investigated the experimental challenges to develop a generic methodology and provide clear guidelines of the operating limits of various interfacial rheometers, including the interfacial needle shear rheometer, the double wall ring, and the bicone geometries.

The work has great practical use to help scientists and engineers identify bad data and understand its cause. The paper extends to interfacial rheometry an approach pioneered by Ewoldt for bulk rheometry, which constitutes a book chapter and is the topic of a recorded webinar, "Experimental challenges of shear rheology: How to avoid bad data,” which has been viewed more than 8,000 times.

Ewoldt, who also holds a Kritzer Faculty Scholar appointment, conducts fundamental research in fluid mechanics and rheology of complex fluids motivated by both their unavoidable and opportunistic novel functionality. Work often involves interdisciplinary collaborations and is a combination of experiment and theory. Complex fluids are ubiquitous in nature and in man-made applications, enabling his research to extend from bioengineering to manufacturing and robotics. He regularly lectures at rheology short courses in the U.S. and Europe.