Convective Assembly of Nanostructured Materials for Energy and BioMEMS Applications
Speaker: Dr. James Gilchrist
Department of Chemical Engineering
Lehigh University, Bethlehem, PA
Convective deposition of nano- and microscale particles is used as a platform for scalable nanomanufacturing of surface morphologies to control and enhance photon, electron, and mass transport. The fundamental mechanism behind self-organization of these particles is particle attraction driven by the local capillary interactions of particles confined in a thin film of an advancing meniscus. Our work focuses primarily on fabrication of self-assembled colloid monolayers while this same process can be used for fabricating various submonolayer morphologies and three dimensional colloidal crystals. By focusing on thin film dynamics, we can control morphology and various instabilities that occur during deposition of mono- and bidisperse suspensions. For instance, by adjusting the suspension profile, we control assembly from a particle-by-particle deposition to a pre-organized deposition mode that affects the deposited morphology. Likewise, lateral mechanical oscillatory motion of the substrate alters the mode of deposition increasing the rate of deposition and reducing the sensitivity of the process to fabricate crystalline monolayers. This process has been successful in fabricating coatings that enable or enhance performance of light emitting diodes (LEDs and OLEDs), dye sensitized solar cells (DSSCs), polymeric and inorganic membranes, and cell capture platforms. Each application, including our goal toward making this an industrially-relevant scalable nanomanufacturing process, will be discussed briefly. This work is currently supported by the NSF (CBET), DOE, and the PA NanoMaterials Commercialization Center.
Dr. James Gilchrist is an Associate Professor of Chemical Engineering at Lehigh University, currently on sabbatical visiting the Department of Chemical Engineering at the California Institute of Technology for the 2011-2012 academic year. Gilchrist directs the Laboratory for Particle Mixing and Self-Organization with research interests spanning various particle technologies including nanoparticle self-assembly, suspension rheology and transport, hemodynamics, microfluidics, chaotic mixing, and granular dynamics. He received his B.S. in Chemical Engineering from Washington University in St. Louis and Ph.D. from Northwestern University. Prior to joining the faculty of Lehigh University in 2004, he was a postdoctoral research associate in the Department of Materials Science and Engineering at University of Illinois. Prior to his current appointment he held the P.C. Rossin Assistant Professorship from 2007-2010 and granted the North American Mixing Forum Young Faculty Award in 2007. Gilchrist is a Co-Founder of PAower Optics, LLC which focuses on licensing, developing, and commercializing various technologies related to scalable nanomanufacturing of microlens array technologies, especially with regard to developing commercial dye sensitized solar cells.