Laboratory for Particle Mixing and Self-Organization
Center for Advanced Materials and Nanotechnology
Center for Photonics and Nanoelectronics
Center for Polymer Science & Engineering
Engineered Particles Institute
My research and scholarly activities are designed to impact both science and engineering through fundamental studies of particulate systems. From an engineering viewpoint particle technology is ubiquitous, including pharmaceutical, chemical, agricultural, food, cosmetic, ceramic, electronic, and mining processes and in an uncountable number of natural processes including sediment transport in rivers, dune formation, and blood flow. Ideal particulate systems, often considered model complex systems, are typically far-from-equilibrium dissipative processes that result in self-organization and complex behavior. These systems are scientifically intriguing because they generally demonstrate behavior that is largely unpredictable by simple integration of constituent interactions. While the two-body interactions between individual particles are well-defined, the resulting phase behavior, structure, and dynamics of these systems often cannot be directly derived from relatively simple binary interactions. Unlike most single-phase fluids, a single set of constituent equations describing a broad range of suspension/granular flows does not exist; consequently these systems are poorly understood at all levels. The design and troubleshooting of solids handling and processing is in many ways as much an art as it is a science.
An overarching objective of my research is to develop a better understanding of these far-from-equilibrium particulate processes exhibiting complexity and self-organization. Research in our Laboratory for Particle Mixing and Self-Organization investigates phenomena ranging from the nano- to macroscale typically divided into colloidal and granular systems. To accomplish this, we identify prototypical complex systems for study and develop new experimental, computational, and analytical methods of investigation and analysis. Current projects include suspension transport in chaotic flows, suspension rheology and microstructure, convective deposition, suspension dielectrophoresis, and granular dynamics in vibrated systems. Paired with this fundamental research is the development of applications involving novel processes, materials, and devices. As the primary focus of my research is fundamental by nature, most applications resulting from this research are facilitated through collaborations developed since coming to Lehigh University. Applications include microfluidic- and industrial-scale mixing and separation, light emitting diode and dye sensitized solar cell coating and internal structure fabrication, fabrication of BioMEMS sensor platforms, and dynamic powder density measurement for online process analysis. My long-term interests aim to further fundamental understanding of suspensions and granular dynamics and to devise novel ways of controlling these interactions for applications.
Honors and Awards
2013- Class of 1961 Associate Professorship
2011-2012 Visiting Associate and Lecturer, California Institute of Technology
2010- AIChE Fluid Mechanics Executive Committee
2010- AIChE Particle Technology Forum Executive Committee
2010- AIChE North American Mixing Forum Executive Committee
2009 Best Paper Award, AIChE Area 3C
2008 Best Paper Award, IEEE Photonics Global Conference in Singapore
2008 Cover Article in Langmuir
2007-2010 P.C. Rossin Assistant Professorship
2007 Young Faculty Award, North American Mixing Forum
Selected Journal Articles (For more info: http://chaos.cc.lehigh.edu)
B. Wang, A. L. Weldon, P. Kumnorkaew, B. Xu, J. F. Gilchrist, and X. Cheng, "Effect of Surface Nanotopography on Immunoaffinity Cell Capture in Microfluidic Devices", Langmuir, 27, 11229-37, 2011.
B. Xu and J. F. Gilchrist, "Shear migration and chaotic mixing of particle
suspensions in a time-periodic lid-driven cavity", Physics of Fluids, 22, 053301, 2010.
C. Gao, S. D. Kulkarni, J. F. Morris, and J. F. Gilchrist, "Direct investigation of anisotropic suspension structure in pressure-driven flow", Physical Review E, 81, 041403, 2010.
P. Kumnorkaew, A. L. Weldon, and J. F. Gilchrist, "Matching Constituent Fluxes for Convective Deposition of Binary Suspensions", Langmuir, 26 (4), 2401-2405, 2010.
"Light Extraction Efficiency Enhancement of InGaN Quantum Wells Light-Emitting Diodes with Polydimethylsiloxane Concave Microstructures", Y. K. Ee, P. Kumnorkaew, R. A. Arif, H. Tong, J. F. Gilchrist, and N. Tansu, Optics Express, vol. 17(16), pp. 13747-13757, August 2009.
"Mixing and segregation of microspheres in microchannel flows of mono- and bi-dispersed suspensions", C. Gao, B. Xu, and J. F. Gilchrist, Physical Review E, 79, 036311, 2009.
"Investigation of the Deposition of Microsphere Monolayers for Fabrication of Microlens Arrays", P. Kumnorkaew, Y. Ee, N. Tansu, and J. F. Gilchrist, Langmuir, 24 (21), 12150-12157, 2008. (Cover Article)
"Enhancement of Light Extraction Efficiency of InGaN Quantum Wells Light Emitting Diodes Using SiO2 Microspheres", Y. K. Ee, R. A. Arif, P. Kumnorkaew, N. Tansu, and J. F. Gilchrist, Applied Physics Letters, 91, 221107, 2007.
"Phase Behavior and 3D Structure of Strongly Attractive Microsphere-Nanoparticle Mixtures", J. F. Gilchrist, A. T. Chan, E. R. Weeks, and J. A. Lewis, Langmuir, 24, 11040, 2005.
"Segregation-Driven Organization in Chaotic Granular Flows", K. M. Hill, D. V. Khakhar, J. F. Gilchrist, J. J. McCarthy, and J. M. Ottino, Proceedings of the National Academy of Sciences, 96(21), pp. 11701-11706, 1999. (Cover Article)