Michael D. Graham

Michael D. Graham

University of Wisconsin-Madison

Chemical Engineer
Awarded Bingham Medal 2024
Fellow, Inducted 2024
University of Wisconsin-Madison weblink
Citation

For foundational and pioneering theoretical contributions to rheology, including advances in understanding the structure and dynamics of confined flowing polymer solutions, instabilities in viscoelastic flows, turbulent drag reduction, collective dynamics in active suspensions, and blood flow in microcirculation underlying health and disease.

Michael D. Graham, Steenbock Professor of Engineering and Harvey D. Spangler Professor in the Department of Chemical and Biological Engineering at the University of Wisconsin-Madison, is the recipient of the 2024 Bingham Medal from the Society of Rheology. Mike’s research uses theory and computation to understand the rheology and dynamics of complex fluids over a wide range of length and time scales. His research is distinguished both by the impressive breadth of topics where he has done groundbreaking and influential work and the exceptional quality and strong focus on achieving fundamental mechanistic insight in rheology and fluid dynamics.

Mike received his Ph.D. in chemical engineering from Cornell University in 1992 with the late Paul Steen. Following his Ph.D., Mike was a postdoctoral fellow at the University of Houston (with Dan Luss) and Princeton University (with Yannis Kevrekidis) before starting his independent career as an Assistant Professor in the Department of Chemical and Biological Engineering at the University of Wisconsin-Madison in 1994.

Mike has been recognized with several impressive awards and accolades, including the William Schowalter Lecture Award from the American Institute of Chemical Engineers in 2019 for outstanding accomplishments in theoretical and computational fluid dynamics, the Stanley Corrsin Award from the Division of Fluid Dynamics at the American Physical Society in 2015, a highly prestigious Vannevar Bush Faculty Fellowship from the Department of Defense, several named lectureships at peer institutions, and nearly 200 invited seminars. Mike has a long and dedicated record of service with the Society of Rheology, including serving as President of SoR (2020-2021), Vice President (2018-2019), Chair and Member of the Bingham Medal Committee, Technical Co-Chair of the SoR Annual Meeting in 2007, and several other roles. He previously served as Editor-in-Chief of the Journal of Non-Newtonian Fluid Mechanics (2013-2015) and Associate Editor of the Journal of Fluid Mechanics, (2005-2012).

Mike’s research focuses on two major areas: (1) microscale rheology and dynamics of multiphase and active fluids, and (2) flow instabilities, nonlinear dynamics, and turbulence in Newtonian and complex fluids. In the area of microscale rheology, his work has focused on understanding the dynamics of DNA molecules in microfluidic confinement, the dynamics of blood cells in flow, collective dynamics in bacterial swimming, the dynamics of thin deformable sheets in flow, and the rheology of dilute micellar surfactant solutions. In the area of flow instabilities and turbulence, his work has elucidated complex interactions between rheology and fluid dynamics giving rise to turbulent drag reduction in polymer and surfactant solutions. In all cases, Mike and his research group have made numerous impactful contributions to the field of rheology that have given our community a bevy of new scholarly ideas.

A main focus of Mike’s work lies in understanding the microhydrodynamics and rheology of polymer solutions under confinement. Mike’s research has been at the forefront of efforts to understand the behavior of DNA and polymers in confined spaces. One of Mike’s seminal contributions in this area was the development of a method for coarse-grained Brownian Dynamics simulations of flowing polymer solutions in a confined geometry that accurately accounts for both intramolecular and wall-induced hydrodynamic interactions (HI) (Jendrejack et al., J. Chem. Phys 2004). This work relied on development of a self-consistent coarse-grained Langevin description of the polymer dynamics, together with a numerical simulation of the flow in the confined geometry that is affected by the motions of polymer segments. Using this groundbreaking method, Mike’s group was able to computationally capture experimental observations regarding the migration of flexible polymers away from solid surfaces in dilute solutions. Mike further developed a coarse-grained molecular theory that incorporates both HI and velocity gradient-dependent conformations, leading to new predictions of non-monotonic concentration profiles (Ma and Graham, Phys. Fluids, 2005). Subsequent experimental validations have confirmed the accuracy of these predictions, and related work extended these concepts to polymer dynamics in oscillatory flows in microchannels (Chen et al., Macromolecules 2005) and development of an immersed boundary method for Brownian dynamics simulation of DNA and polymer chains in complex geometries (Zhang et al., J. Chem. Phys., 2012). His work in this area has broad implications beyond DNA, with applications in various processes involving confined complex fluids.

In a second area, Mike’s work has provided invaluable insights into crucial aspects of blood flow, shedding light on the behavior of blood components and their implications for disease and biological outcomes. The distribution of particles such as white blood cells and platelets during blood flow plays a pivotal role in determining physiological responses. One of the key phenomena Mike investigated involves the margination of blood components (Kumar and Graham, Phys. Rev. Lett., 2012; Kumar and Graham, Soft Matter 2012), where flexible red blood cells migrate toward the center of blood vessels, leaving a cell-free layer at the vessel wall. In contrast, stiff white blood cells and small platelets preferentially localize near the walls. This phenomenon, known as margination, is critical for physiological responses such as inflammation and hemostasis. Mike’s research elucidated the mechanisms underlying margination while further highlighting its significance in the pathophysiology of certain blood disorders (Fay et al., Proc. Natl. Acad. Sci., 2016; Cheng et al., Sci. Adv. 2023). A notable contribution from Mike’s group is the development of a kinetic theory (Henriquez Rivera, et al., Phys. Rev. Fluids, 2016) that captures key effects observed in shear-driven cell-cell collisions and wall-induced hydrodynamic migration. This mechanistic insight paved the way for understanding cell dynamics in sickle cell disease (Zhang et al., Phys. Rev. Fluids, 2020).

Mike’s contributions in the two additional areas of research – active particle dynamics and turbulent drag reduction – are similarly impactful and impressive. Mike is broadly considered as one of the founders of the field of active particle dynamics, with his seminal contributions including: (1) the first computational study of collective swimming using an accurate microhydrodynamic description of swimmers using a force dipole (Hernandez et al., Phys. Rev. Lett., 2005), and (2) the first direct simulations of large populations of hydrodynamically interacting swimmers in a spatially periodic flow domain using efficient computational methods (Underhill et al., Phys. Rev. Lett., 2008). In a fourth area, Mike has made key contributions to the field of viscoelastic turbulence. His group discovered the phenomenon of hibernating turbulence, where temporarily suppressed turbulence due to viscoelasticity later emerges after the polymer chains relax, leading to a cycle of low and high degrees of drag reduction (Phys. Rev. Lett. 2010). More recently, his group discovered that the recently observed phenomenon of elastoinertial turbulence arises from viscoelastic excitation of the Tollmien-Schlichting waves of classical linear stability theory – these do not play a role in Newtonian turbulence, but in viscoelastic turbulence they emerge as central players (Phys. Rev. Lett. 2019).

Mike has authored or co-authored two textbooks that are routinely used in engineering curricula at peer institutions. In his text entitled Microhydrodynamics, Brownian Motion and Complex Fluids, Mike provides a clear explanation and coherent treatment of topics that are not readily found in alternative texts including multipole expansions, fundamental solutions to the Stokes equation in confined geometries, coarse-grained models and stochastic differential equations for polymers and suspensions, and applications to linear viscoelasticity and non-linear rheology. A second graduate-level textbook entitled Applied Mathematics for Chemical and Biological Engineers, co-authored with Jim Rawlings, provides a comprehensive treatment of mathematical methods in chemical engineering.

On a personal note, I have been inspired by Mike’s impressive research since graduate school, when Mike’s work on modeling hydrodynamic interactions in long chain polymers directly influenced my efforts in developing Brownian dynamics simulations to complement our single-polymer dynamics experiments on large DNA molecules in extensional flow. As a Ph.D. student, I distinctly recall giving conference presentations at SoR meetings, with Mike sitting in the front row, giving encouraging head nods, and asking supportive and insightful questions. Mike has continued to serve as a supportive mentor for me and several other junior faculty members in the field for many years, and for this, we are eternally grateful.

Mike Graham is a world-leading researcher in rheology and fluid mechanics. His impressive body of work includes several impactful discoveries that have provided the foundation for new lines of inquiry. Given his deeply impactful scientific work – and his selfless and dedicated service to the Society of Rheology – Mike Graham is highly deserving of the Bingham Medal from The Society of Rheology. He truly embodies the highest qualities of scholarship, and we are deeply fortunate to have him as part of our professional community.