Michael J. Solomon

Biography

  Michael Solomon is Professor of Chemical Engineering and Professor of Macromolecular Science and Engineering at the University of Michigan. He was previously Dow Corning Assistant Professor of Chemical Engineering and has been member of the Michigan Faculty since 1997. Prior to joining U-Michigan, Mike was a post-doctoral research fellow at the University of Melbourne, Australia. He received his B.S. in chemical engineering and economics from the University of Wisconsin at Madison in 1990 and his Ph.D. in chemical engineering from the University of California at Berkeley in 1996. He was a Rotary Foundation International Fellow in economics at the Université d’Aix-Marseille II, Aix-en-Provence, France from 1990-1991.Solomon’s research interests are in the area of complex fluids – soft materials with properties intermediate between fluids and solids. His group has developed and applied 3D confocal microscopy methods to study the soft matter phenomena of self-assembly, gelation, and the biomechanics of bacterial biofilms. His work has also included discovery of a universal scaling for polymer scission in turbulence that identifies the limits that scission imposes on turbulent drag reduction. Other research interests have included the rheology of polymer nanocomposites, the microrheology of complex fluids and the microfluidic synthesis of anisotropic particles.His teaching interests have included development of undergraduate courses in polymer science and engineering, molecular engineering, and chemical engineering process economics as well as graduate electives in nano and colloidal assembly and light scattering. Mike has received the College of Engineering 1938E Award (2002), the University of Michigan Russel Award (2003), the U-M ASEE Outstanding Professor of the Year Award (2006), the Rackham Graduate School’s Faculty Recognition Award (2008) and the COE Education Excellence Award (2010). He has been recipient of the NSF CAREER award, 3M’s non-Tenured Faculty award, and the 2011 Soft Matter Lectureship from the Royal Society of Chemistry’s journal Soft Matter. Solomon previously chaired the Society of Rheology’s Education Committee and its Metzner Award Committee as well as the Fluid Mechanics Programming Committee of the American Institute of Chemical Engineers. He is current member of the Editorial Advisory Board of the Journal Rheologica Acta. Currently, Solomon is Associate Dean for Academic Programs and Initiatives at the Horace H. Rackham School of Graduate Studies at the University of Michigan.

Research Interest

Our research investigates complex fluids – soft materials with properties intermediate between fluids and solids. Our current interests include nanocolloidal assembly, colloidal gelation, and the biomechanics of bacterial biofilms. Applications that interest us include creating new optical materials, sensors, biomedical devices and procedures, as well as materials for energy management. Nanocolloidal assembly The assembly of nanocolloids into useful structures has long been a key aim of chemical engineers and materials scientists. For example, ordered arrays of colloidal particles formed in the liquid state can be further processed to yield photonic crystal structures useful for sensing and optical materials. Yet, the success of this technological aim is severely hindered by some deep fundamental problems. For example, the crystal structures that have been fabricated to date are disappointingly small, most likely because typical nanocolloidal building blocks are not nearly complex as molecules. We address this challenge by synthesizing anisotropic colloids and assembling them with the assistance of applied electric, shear and gravitational fields. We collaborate with Profs. Sharon Glotzer, Mark Burns and Joanna Millunchick in pursuit of this aim. In a second effort, we address the fact that the typical size of the ordered arrays that have been produced in academia is currently too small for real-world applications. In collaboration with Professor Ron Larson, we have investigated the complex fluid dynamics of large-scale methods for colloidal crystal production, such as spin coating. These questions are studied within a collaborative, student-drive research program that includes novel colloid synthesis, direct visualization of assembly structure and dynamics by confocal microscopy as well as rheological measurements. Colloidal gelation Colloidal gelation is a common industrial process to manage the rheological and microstructural properties of complex fluid formulations used in the stabilization of consumer products, ceramic materials and pharmaceutical formulations. By developing new 3D confocal microscopy methods, our group has made fundamental discoveries about gels that are currently being applied in industry to develop new materials and complex fluid processing methods. Currently, we are engaged in an investigation of the origin of rupture and yielding in colloidal gels. The work involves a combination of advanced microscopy techniques, flow cell fabrication using methods such as microfabrication, and rheological measurements. Biomechanics of bacterial biofilms With Dr. John Younger of the U-Michigan Department of Emergency Medicine and collaborators at two other universities, we are exploring the biomechanical properties of bacterial biofilms. Biofilms are colonies of microorganisms that are pervasive in a range of natural and industrial settings. They can also grow on devices, such as intravascular catheters, that are introduced into the body as part of medical practice. Biofilm structure and mechanics is thought to play a protective role by, for example, improving the resistance of bacteria to antibiotic treatments. The aim of this project is to understand and measure the mechanical properties of biofilms of size about 10 – 100 microns, since these dimensions match the scales relevant to medical practice. As part of this work, we have developed a flexible microfluidic rheometer for micromechanical measurements of bacterial biofilm elasticity. Current work is focused on molecular characterization of the extracellular polysaccharides present in biofilms, rheological characterization of whole biofilms, and confocal microscopy visualization of the complex microscopic structure of biofilms. Our research is supported by NSF, NIH, DOE, and Procter & Gamble.