2025 ISM–NIST Fellows: Narayan Das and Ruth Crothers

Posted in ISM Stories News Story

The Institute for Soft Matter and Metrology (ISM) is pleased to welcome the 2025 ISM–NIST Fellows, Narayan Das and Ruth Crothers, whose research spans polymer mechanics, colloidal materials, and advanced measurement techniques. As part of the ISM–NIST Fellowship program, both fellows will leverage ISM’s unique experimental capabilities and collaborative environment to advance fundamental understanding in soft matter science.

Narayan Das: ISM–NIST Fellow | Polymer Networks and Mechanics

Narayan Das joins Georgetown from the Indian Institute of Science Education and Research (IISER) Kolkata, India, where he developed a strong foundation in polymer and soft-materials research. His current project focuses on mechanochemical barriers for novel energy dissipation mechanisms in polymer networks, with the goal of understanding how complex soft materials respond to mechanical stress.

Narayan’s research relies on a combination of experimental and analytical tools, including dynamic mechanical analysis, Instron testing, nuclear magnetic resonance (NMR), gel permeation chromatography (GPC), and 3D printing. Together, these methods allow him to probe the structure–property relationships that govern the mechanical behavior of polymer networks.

At ISM, Narayan is collaborating with Professor Nagarjuna Gavvalapalli in the Department of Chemistry, exploring how molecular-level interactions influence macroscopic mechanical properties. Through this work, he aims to generate high-quality, reproducible data that is relevant to advanced manufacturing, while contributing to impactful scientific publications.

Looking ahead, Narayan hopes to establish a strong foundation for an independent research career, using ISM’s advanced measurement capabilities to build a comprehensive understanding of soft polymer networks and their real-world applications.

Ruth Crothers: ISM–NIST Fellow | Colloidal Particles and Rheology

Ruth Crothers joins ISM from Radboud University in the Netherlands, where she completed her PhD under the supervision of Professor Roel P. A. Dullens in the Department of Physics and Chemistry of Soft Matter. During her doctoral work, Ruth’s research focused on the rotational dynamics of colloidal microspheres in the fluid, crystal and glass phase. She learnt to synthesize a colloidal microsphere, previously developed by the group, that uniquely allows the direct observation of rotational and translational dynamics of every particle in a population allowing insight into the dynamics at both an ensemble averaged and single-particle level.

At Georgetown, Ruth is applying her expertise in colloidal synthesis to explore how particle shape and polydispersity can be used as tools to control the rheological behavior of colloidal suspensions. A key contribution from her PhD is a unique synthesis method that enables the creation of truly polydisperse particle populations with controlled polydispersity ranging from 5% to 30%. This capability allows researchers to systematically investigate how variations in particle size distribution affect material flow and mechanical properties; this is an area that is typically difficult to study using conventional techniques.

Ruth is primarily collaborating with Professor Blair and his lab, combining her experience in particle synthesis with the group’s expertise in rheology. Together, they aim to connect microscopic particle behavior with macroscopic material response.

During her time as an ISM–NIST Fellow, Ruth hopes to further expand the toolkit of colloidal synthesis by exploring new ways to manipulate particle shape and surface chemistry, opening up new experimental pathways for designing and understanding soft materials.

Through their complementary research interests, Narayan Das and Ruth Crothers exemplify the interdisciplinary mission of the ISM–NIST Fellowship. Their work strengthens ISM’s role as a hub for innovative measurement science, bridging fundamental research with practical applications in materials design and manufacturing.