2025 AIChE Annual Meeting
November 2 – 6, 2025
Boston, MA
John B. Hynes Veterans Memorial Convention Center, Marriott Copley Place, Sheraton
Link to Meeting Registration

Special Session: Coating Science, Technology, and Applications (Invited)

Tuesday, November 4 3:30PM-6:00PM EST
Hynes Convention Center, Room 302
Session Chairs: Kristianto Tjiptowidjojo (Avery Dennison), Eric Vandre (3M),
Ted Lightfoot (Ted Lightfoot LLC), Tequila Harris (Georgia Tech)

Invited Talks and Speakers

426a – Kinetic wetting of a solid by a liquid exhibiting a diffuse interface between the liquid and vapor phases.

E. J. (Ted) Lightfoot – Ted Lightfoot LLC

Abstract

Dynamic wetting of a solid by a liquid is critical in a number of applications including high-speed coating, enhanced oil recovery, penetration of a liquid into a solid matrix, and the spreading of drops on a solid surface. Air entrainment due to dynamic wetting failure is often the fundamental limit to line speed in liquid coating operations. Numerous empirical and theoretical approaches have been taken to modeling dynamic wetting of a solid by liquids with sharp interfaces between the liquid and vapor phases. However, it is well known that liquid vapor interfaces are not sharp at the molecular level. Here we discuss the effects a diffuse liquid vapor interfaces on wetting. More specifically, we examine, in the vein of Ockham’s razor, the minimum number of assumptions required to explain certain intriguing features of dynamic wetting under the assumption of a diffuse liquid vapor interface.

Speaker Bio

Ted Lightfoot spent 35 years with DuPont and DOW-Dupont making photographic film, solvent cast films, optical films and other proprietary developments. He was the first American to be named an Industrial Fellow at the University of Minnesota Coating Fundamentals program was a founding director of the ISCST as well as a founder and former leader of DuPont’s internal coating network. He retired from DuPont in 2019 and started Ted Lightfoot LLC, a consulting company in film casting, coating, drying, and laminating.

426b – Fabrication of a Multi-Material Devices Using Novel Slot Die Configurations

Tequila Harris – Georgia Tech

Abstract

Advancements in electronics, membranes, organic solar cells, and fuel cells often necessitate complex structures that require patterning and multilayer designs, which require cumbersome, expensive fabrication techniques. Traditional fabrication methods for these devices typically involve multiple coating tools, drying chambers, and additional patterning techniques that often require subtractive fabrication steps. Collectively, this leads to extensive equipment and facilities and increases in energy consumption, overall costs, and carbon footprint. To address these challenges, here we present one-step continuous manufacturing to fabricate complex multilayer, multi-material thin film structures using an advanced slot die technique (co-deposition and dual-layer slot die) within a laboratory scale roll-to-roll (R2R) system. The co-deposition slot die enables patterning multiple materials across the web (z-axis), while the dual-layer slot die enables coating multiple materials through the thickness (y-axis). In this work, several conductive inks and non-conductive polymers were fabricated simultaneously. Guided by coating fundamentals, the width and thickness of fabricated thin film were controlled across two or three layers. The electrical properties of the multilayer thin films were found to be comparable with reported values in the field. Additionally, material properties such as layer adhesion were found to be excellent, showing no signs of delamination. Broad implementation of the presented fabrication process for multilayer, multi-material thin film, can lead to faster production rates with significant reductions in infrastructure, energy, and material waste.

Speaker Bio

Dr. Tequila A. L. Harris is an Associate Professor in the George W. Woodruff School of Mechanical Engineering, at Georgia Institute of Technology and Principal Investigator of the Highly Advanced Roll-to-Roll iManufacturIng Systems (HARRIS) group.  Prior to joining Georgia Tech, she earned her Masters and Doctorate degrees from Rensselaer Polytechnic Institute and a Bachelors in Physics from Lane College.  Dr. Harris investigates the scalability of simple and complex thin film structures and patterns from solution and develop innovative manufacturing technologies to fabricate films and devices, at lab and pilot scales.  The connectivity between process-structure-property-function of thin films is explored in the HARRiS lab using traditional and advanced techniques invented in her group.  More fundamentally, mechanisms that cause failure pre- and post-processing are elucidated to discovery mitigation strategies.  She utilizes experimental analysis, computational fluid dynamics, and analytical modeling approaches to develop process models and approaches to predict and control the quality of thin films coated/cast on permeable and impermeable substrates. By addressing the associated complex fundamental problems, she aims to impact a plethora of industries and fields such as energy, electronics, clean water, among others.  Dr. Harris has received several awards and honors, of note, the International Society of Coating Science and Technology L. E. Scriven Young Investigator Award, the National Science Foundation CAREER Award and a finalist for the 2023 Women in Technology Award.

426c – Manufacturing Models for the Hydrogen Economy: Slot Coating, Slide Coating, and Related Models

Rekha Rao – Sandia National Laboratories

Abstract:

Low-defect manufacturing of polymer electrolyte membrane (PEM) fuel cells and electrolyzers are important to the hydrogen economy. The M2PAC roll-to-roll consortium has a mission to advance efficient, high-throughput, and high-quality manufacturing methods and processes for clean hydrogen technologies to accelerate domestic manufacturing and reduce the capital cost of durable and high-performing systems. The manufacturing of these fuel cells and electrolyzers utilizes slot-die coating. In this process, a particle-filled ink flows through a slot die and is deposited onto a moving substrate. Fluid instabilities can occur such as ribbing or barring. Additional defects can occur via settling of the ink or inhomogeneous deposition pattern during the drying step. Computational models of coating flows can determine operating windows to reduce defects and increase yields. Fuel-cell inks tend to be highly-particle filled polymer solutions and exhibit shear thinning rheology while electrolyzer inks have lower particle loading and exhibit Newtonian rheology. In this talk, we will discuss work on modeling coating and drying of PEM fuel cell and electrolyzers manufacturing and plans for future work.

*SAND2025-06236A. Sandia National Laboratories is a multimission laboratory managed and operated by National Technology and Engineering Solutions of Sandia, LLC, a wholly owned subsidiary of Honeywell International, Inc., for the U.S. Department of Energy’s National Nuclear Security Administration under contract DE-NA0003525.

Speaker Bio

Dr. Rekha Rao is a Distinguished Member of Technical Staff at Sandia National Laboratories. She came to Sandia in 1990 after earning her BS from UC Berkeley and Ph.D. from the University of Washington, both in Chemical Engineering. Rekha is an expert in the computational mechanics of complex fluids, including theoretical development, numerical algorithms, and finite element implementation. She is one of the founding authors of Goma, an R&D 100 winning open-source software package for process flow modeling. She has authored or coauthored over 125 peer-reviewed journal articles, reports, and conference proceedings. Rekha’s research has spanned model development in support of energy-production, environmental issues, polymer processing, and manufacturing. Her work on foam process models have led to publications, collaborations with industry, and to a production computational capability impacting manufacturing yields. Rekha is the President of the US Association of Computational Mechanics and the Chair of the Female Research Committee of the International Association of Computational Mechanics, mentoring and encouraging women in computational mechanics.

426d – Pinning–depinning transition of droplets on inclined substrates with a three-dimensional topographical defect

Satish Kumar – University of Minnesota

Abstract

Droplets on inclined substrates can depin and slide freely above a critical substrate inclination angle. Pinning can be caused by topographical defects on the substrate, and understanding the influence of defect geometry on the pinning–depinning transition is important for diverse applications such as fog harvesting, droplet-based microfluidic devices, self-cleaning surfaces, and inkjet printing. Here, we develop a lubrication-theory-based model to investigate the motion of droplets on inclined substrates with a single three-dimensional Gaussian-shaped defect that can be in the form of a bump or a dent. A precursor-film/disjoining-pressure approach is used to capture contact-line motion, and a nonlinear evolution equation is derived which describes droplet thickness as a function of the position along the substrate and time. The evolution equation is solved numerically using an alternating direction implicit finite-difference scheme to study how the defect geometry influences the critical inclination angle and the shape of a pinned droplet. It is found that the critical substrate inclination angle increases as the defect becomes taller/deeper or wider along the direction lateral to the droplet-sliding direction. However, the critical inclination angle decreases as the defect becomes wider along the sliding direction. Below the critical inclination angle, the advancing contact line of the droplet at the droplet centerline is pinned to the defect at the point having maximum negative slope. Simple scaling relations that reflect the influence of defect geometry on the droplet retention force arising from surface tension are able to account for many of the trends observed in the numerical simulations [1].

[1] N. V. Mhatre and S. Kumar, Soft Matter 20, 3529-3540 (2024).

Speaker Bio

Satish Kumar is a Distinguished McKnight University Professor at the University of Minnesota, where he is on the faculty of the Department of Chemical Engineering and Materials Science.  Prof. Kumar received his undergraduate degree from Minnesota (1993), and his master’s (1994) and doctoral degrees (1998) from Stanford University, all in chemical engineering.  Following postdoctoral work at École Normale Supérieure (Paris) and the University of Michigan, he joined the faculty at Minnesota in 2001.   He is both a Fellow and an Outstanding Referee of the American Physical Society, is Co-Editor-in-Chief of the Journal of Engineering Mathematics, and serves on the editorial board of the Journal of Non-Newtonian Fluid Mechanics.  He has served as a member of the Executive Committee of the American Physical Society Division of Fluid Dynamics, is a former president of the International Society of Coating Science and Technology, and is currently a member of the U. S. National Committee on Theoretical and Applied Mechanics.  Prof. Kumar served for 7 years as Faculty Director of the Industrial Partnership for Research in Interfacial and Materials Engineering (IPRIME), a university-industry consortium, and is currently co-director of its Coating Process Fundamentals Program.  Prof. Kumar’s research involves integration of transport phenomena, colloid and interface science, rheology, applied and computational mathematics, and experiments to address fundamental issues motivated by problems in materials processing.  These fundamental investigations, which are described in over 170 journal articles and 28 PhD theses, are frequently inspired by industrial applications such as coating and printing processes, polymer processing, nanofluidics/microfluidics, and energy.

426e – Bioinspired coatings and surfaces for haptic engineering

Lilian Hsiao – North Carolina State University

Abstract

In the animal kingdom, there are many examples of surfaces and coatings that can effectively control friction, even in extreme environments where high shear rates and complex fluids are present. This talk focuses on the fundamental interfacial principles that can be used to engineer the sliding friction at haptic interfaces. The first example is the use of surface patterns to separate length scales in lubricated flows, which is applicable even to real-world systems in soft robotics and tactile sensing. The second example is the incorporation of fatty amide organic molecules that form slip planes at the interface, such as that between human skin and nonwoven textiles. These materials generate triboelectric power when tapped, where the slip additives serve as a crucial gateway between charge carrying efficiency and human haptic sensation.

Speaker Bio

Lilian Hsiao is University Faculty Scholar and Associate Professor of Chemical and Biomolecular Engineering at North Carolina State University. She received a B.S. in Chemical Engineering from the University of Wisconsin-Madison in 2008, Ph.D. in Chemical Engineering from the University of Michigan in 2014, and conducted postdoctoral work at the Massachusetts Institute of Technology. Her research program specializes in the use of in situ confocal microscopy and rheological tools to understand the physics of deforming soft materials. Her research work has won numerous awards, including the American Physical Society DSOFT Early Career Award, Society of Rheology Metzner Award, Camille Dreyfus Teacher-Scholar Award, Sloan Research Fellowship in Chemistry, and the American Chemical Society Unilever Award.

426f – Influence of rheology modifiers on the microstructure evolution of drying paints

James Gilchrist – Lehigh University

Abstract

The evolution of microstructure in drying coatings is essential to the final film properties. Understanding this process and the microstructure during drying is a common question in the coatings industry. There is often a separation between the predicted film and the final applied film due to evolving rheology and particle-scale interactions. There are few techniques that are able to provide this information in situ. This work focuses on tracking fluorescent silica particles that behave as surrogate pigment using high-speed laser scanning confocal microscopy to give the time evolution of microstructure as a function of the formulation. Specifically, the addition of cellulose-based rheology modifiers is examined to understand the impact of rheology modifiers on the drying process and resulting microstructure. Clear changes in particle stability, such as the onset of depletion or other attractive interactions, are observed during drying that significantly alter the microstructure evolution during drying. Using the 3D particle locations, the evolution of this microstructure allows thorough statistical analysis, resulting in simulation-like detail from physical experiments.

426g – Addressing Challenges in Industrial R&D Coating

Kara Meyers – 3M Company

Abstract

Coating in industry provides its own unique challenges. As materials science innovations continue to drive towards new and more sustainable products, our ability to characterize and process those materials must also advance. As a coating engineer at 3M’s Corporate Research Process Labs, I will discuss a few key fundamental technical challenges relevant to coating of complex, viscoelastic rheologies to produce a range of products – highlighting importance of probing fundamental understanding in the spirit of improving coating across multiple products and industries.

Speaker Bio

Kara graduated from the University of Minnesota, Twin Cities with dual Bachelor’s degrees in Chemistry and Chemical Engineering, with a Mathematics minor. Since graduation, she has gained expertise in multiple coating and patterning processes as part of 3M’s Corporate Research Process Laboratory – where she has spent her career focused on enabling new products across a broad range of markets through the development of novel process technology platforms. To date, she has developed processes that allow for the reduction or elimination of solvents from new and existing products, and led the development of novel roll-to-roll flexible electronics processes. Through these experiences she has deployed multiple process technologies to several manufacturing sites in the US and internationally, provided input on the design of over $2M of capital equipment, and championed fundamental education efforts within 3M’s technical community. Her current work focuses on the intricacies of handling viscoelastic fluids and mapping fundamental process windows – with the goal of enabling viable processing of more sustainable adhesives. In total, Kara’s work has generated filings in 28 active patent families with 17 granted US patent applications to date. She has received multiple awards from 3M’s internal technical community for creativity and technical excellence as well as external recognition from the Society of Women Engineers (SWE).

Categories: Uncategorized