MITf-Lab Current Research Projects

MITf-Lab Current Research Projects

SUMMARY OF PAST COMPLETED PROJECTS IS AVAILABLE HERE

Project #1: Catalytic Microreactors for Hydrogen Generation and Failure Analysis of Solid Oxide Fuel Cells

DESCRIPTION: This project involves design, fabrication, and theoretical and experimental analysis of novel transient MEMS reactors for hydrogen production via heterogeneous catalysis with in-situ hydrogen separation and integration with PEFC micro fuel cells. These are: (1) a forced flow unsteady-state catalytic reactor operating in the reverse-flow mode, input composition cycling mode, and input temperature cycling mode, and (2) a catalytic reactor exploiting the transient and steady-state spatial reaction patterns by using fractal structuring of the catalytically active surface. The advantages offered by these systems are the following: (a) rapid heat and mass transport, (b) non-equilibrium surface chemistry, (c) energy and chemical conversions at the optimal locations, and (d) high productivity and selectivity (per unit volume). The catalytic microreactors described constitute a new area of research with enormous potential applications in the power generation, chemical, pharmaceutical, aerospace and transportation industries as well as in the biotechnology and military. The examples are the distributed power generators for the space station and Navy warships, power sources for compact remote sensors and instruments, automotive exhaust clean-up systems, and others.

We are developing a unique concept for highly integrated hydrogen generator capable of hydrogen generation from liquid hydrocarbon fuels and in-situ separation and storage of high purity hydrogen to be used as a feedstock for low temperature PEFC energy sources. We have also developed an advanced theoretical methodology which combines the continuous fluid flow, heat and mass transfer models of the process with the statistical mechanical model for adsorption equilibrium within a unified computational framework. Both slip and no-slip flows have been considered depending upon the dimensions of the system. Our analysis has demonstrated the vital importance of appropriate modeling of non-linear near-wall interactions between heat/mass transport and adsorption/desorption for correct predictions of the overall system dynamics. The fundamental scaling relations for characteristic time constants for the system transient response have been also obtained and verified by detailed parametric simulations.

Cost of heterogeneous catalytic systems such as chemical and biological reactors, chemical sensors, and electrochemical fuel cells is primarily determined by the amount of the chemically active catalyst, usually highly expensive noble metals or alloys, that needs to be loaded to achieve desired rate of chemical conversion. This problem has been traditionally addressed by continuous search for less expensive and equally efficient catalyst materials. We have developed an alternative approach for significant reduction of the catalyst loading by optimal structuring of active catalyst surfaces in the heterogeneous chemical reactors and electrochemical sensors and fuel cells. Intuition tells us that any decrease in the active (i.e., loaded with catalyst) surface area should result in an equivalent decrease in the reaction yield and efficiency. However, our findings counter this by showing that the active surface and hence the catalyst loading can be reduced drastically in the diffusion-limited heterogeneous reaction systems, while the conversion rate remains essentially unchanged by using fractals for spatial distribution of the catalyst load. The results indicate that introduction of periodic singularities into the boundary conditions through fractal structuring of the active surface allows a 76% reduction in the catalyst loading while losing only 2.25% of the original rate of chemical conversion. The effect of fractal structuring of the active surface is the most profound to the design of micro/nano scale systems, for which the Peclet (Pe) and Rayleigh (Ra) numbers are intrinsically small due to the small characteristic length scale and body forces. Thus, introduction of periodic singularities into the mass transfer boundary condition is ideally suited for drastically lowering the cost of MEMS devices for chemical and biological processing as well as micro/nanoporous electrodes for fuel cells, and it can be exploited to its fullest extent by utilizing the advances in our abilities to manipulate matter on the micro/nano scale.

Finally, we are also working on the model-based optimal design and failure prediction in the solid oxide fuel cells. This work involves both theoretical and experimental aspects, and is accomplished in collaboration with a number of national labs (NETL, PNNL) and SOFC manufacturers.

Our goals are (1) to develop novel design configurations for transient MEMS reactors and identify integration schemes for development of highly efficient, intimately integrated, and controllable hydrogen generators, (2) to quantify interactions between heat and mass transfer and strong surface chemical/phase transformations (i.e., adsorption, catalysis, evaporation) in the Knudsen layer, (3) to access the effect of non-equilibrium surface chemistry on the near-wall flow and heat/mass transfer in catalytic microreactors, (4) to develop an optimal control strategies for the chemical microreactors under consideration, and (5) to validate theoretical models developed through detailed experimentation.

SPONSOR: Air Products & Chemicals, Inc. (completed), DOE (completed), NASA (completed), GT Strategic Energy Institute (completed), NSF (current).

COLLABORATION: Prof. Levent Degertekin (GT ME), Prof. Jianmin Qu (GT ME), and Dr. Comas Haynes (GTRI)

STUDENTS: Mark Meacham (Ph.D.), Logan McLeod (Ph.D.), Mark Varady (Ph.D.), David Damm (Ph.D.), and Roger Lang (M.S.)

RELEVANT PUBLICATIONS/PATENTS:

  • Baxter, J., Bian, Z., Chen, G., Danielson, D., Dresselhaus, M., Fedorov, A., Fisher, T., Jones, C., Maginn, E., Kortshagen, U., Manthiram, A., Nozik, A., Rolison, D., Sands, T., Shi, L., Sholl, D., Wu, Y., Nanoscale design to enable the revolution in renewable energy, Energy & Env. Sci., 2, 559-588 (2009).
  • McLeod, L., Degertekin, F. L., and Fedorov, A., Determination of the rate-limiting mechanism for permeation of hydrogen through microfabricated palladium-silver alloy membranes, J. Membrane Sci, 341, 225-232 (2009).
  • McLeod, L., Degertekin, F. L., and Fedorov, A., Non-ideal absorption effects on hydrogen permeation through palladium-silver alloy membranes, J. Membrane Sci, 339, 109-114 (2009).
  • Damm, D. L. and Fedorov, A., Batch reactors for hydrogen production: theoretical analysis and experimental characterization, Ind. & Eng. Chem. Res., 48 (12), 5610-5623 (2009).
  • Damm, D. L. and Fedorov, A., Conceptual study of distributed CO2 capture and the sustainable carbon economy, Energy Conversion and Management, 49 (6), 1674-1683 (2008).
  • Damm, D. L. and Fedorov, A., Comparative assessment of batch reactors for scalable hydrogen production, Ind. & Eng. Chem. Res., 47 (14), 4665-4674 (2008).
  • Meacham, J. M., Varady, M., Esposito, D., Degertekin, F. L., and Fedorov, A., A micromachined ultrasonic atomizer for liquid fuels, Atomization and Sprays, 18, pp. 163-190 (2008).
  • Varady, M., McLeod, L., Meacham, J. M., Degertekin, F. L., and Fedorov, A., Integrated MEMS infrastructure for fuel processing: hydrogen generation and separation for portable power generation, J. Micromech. Microeng. (Invited, Special Issue on Power MEMS), 17 (9), S257-S264 (2007).
  • McLeod, L., Degertekin, F. L., and Fedorov, A., Effect of microstructure on hydrogen permeation through thermally stable, sputtered palladium-silver alloy membranes, Appl. Phys. Lett., 90 (26), 261905-261908 (2007).
  • Damm, D. L. and Fedorov, A., 2006, Reduced-order transient thermal modeling for SOFC heating and cooling, J. Power Sources, Vol. 159, pp. 956-967.
  • Damm, D.L. and Fedorov, A., 2006, Local thermal non-equilibrium effects in porous electrodes of the hydrogen-fueled SOFC, J. Power Sources , Vol. 159, pp. 1153-1157.
  • McLeod, L., Degertekin, F. L., and Fedorov, A., Analysis of hydrogen permeation through sub-micron-thick palladium alloy membranes, 2005 ASME Summer Heat Transfer Conference, San Francisco, CA, July 17-22, 2005.
  • Kaisare, N. S., Lee, J. H., and Fedorov, A., 2005, Operability analysis and design of a reverse-flow microreactor for hydrogen generation via methane partial oxidation, Ind. & Eng. Chem. Res., Vol. 44, No. 24, pp. 8323-8333.
  • Damm, D. and Fedorov, A., 2004, "Radiative heat transfer in SOFC materials and components", Journal of Power Sources, Vol. 143, pp. 158-165.
  • Damm, D. and Fedorov, A., 2005, Spectral Radiative Heat Transfer Analysis of the Planar SOFC, ASME Journal of Fuel Cell Science and Technology, Vol. 2, No. 4, pp. 258-262.
  • Meacham, J. M., Varady, M., Degertekin F. L., and Fedorov, A., 2005, "Droplet Formation and Ejection from a Micromachined Ultrasonic Droplet Generator: Visualization and Scaling", Physics of Fluids, Vol. 17, No. 10, pp. 100605-100613.
  • Meacham, J. M., Varady, M., Esposito, D., Degertekin F. L., and Fedorov, A., 2005, "A Micromachined Ultrasonic Atomizer for Liquid Fuels", Atomization and Sprays, in review.
  • Damm, D. and Fedorov, A., "Spectral radiative heat transfer analysis of the planar SOFC", ASME International Mechanical Engineering Congress & Exposition IMECE'04, Anaheim, CA, November 13-19, 2004.
  • Kaisare, N. S., Lee, J. H., and Fedorov, A., 2005, Hydrogen generation via methane partial oxidation in a microchannel reactor with flow reversal: Mathematical formulation and scaling, AIChE Journal, Vol. 51 (8), pp. 2254-2264.
  • Kaisare, N. S., Lee, J. H., and Fedorov, A., 2005, Hydrogen generation via methane partial oxidation in a microchannel reactor with flow reversal: Simulations and analysis, AIChE Journal, Vol. 51 (8), pp. 2265-2272.
  • Meacham, J. M., Ejimofor, C., Kumar, S., Degertekin F. L., and Fedorov, A., 2004, "A Micromachined Ultrasonic Droplet Generator Based on Liquid Horn Structure", Review of Scientific Instruments, Vol. 75, No. 5, pp. 1347-1352.
  • Kikas, T., Bardenshteyn, I., Williamson, C., Ejimofor, C. Puri, P., and Fedorov, A., 2003, "Hydrogen Production in the Reverse-Flow Autothermal Catalytic Microreactor", Industrial & Engineering Chemistry Research, Vol. 42, pp. 6273-6279.
  • Murthy, S. and Fedorov, A. G., 2003, "Radiation Heat Transfer Effects in the Monolith-Type Solid Oxide Fuel Cell", Journal of Power Sources, Vol. 124, No. 2 , pp. 453-458.
  • Phillips, S., Ben-Richou, A., Ambari, A., and Fedorov, A. G., 2003, "Catalyst Surface at Fractal of Cost - A Quest for Optimal Catalyst Loading", Chemical Engineering Science, Vol. 58, No. 11, pp. 2403-2408.
  • Kikas, T., Bardenshteyn, I., Williamson, C., Ejimofor, C., and Fedorov, A.G, Hydrogen Production in the Reverse-Flow Autothermal Catalytic Microreactor, IMRET7 - 7th International Conference on Microreaction Technology, Lausanne, Switzerland, September 7-10, 2003.
  • Zhang, H., Bardenshteyn, I. M., Ejimofor, C. and Fedorov, A.G., "Feedstock for Micro Fuel Cells: Efficient Hydrogen Production in the Reverse-Flow Autothermal Catalytic Microreactors", International Symposium on Micro/Nanoscale Energy Conversion MECT-02, International Centre for Heat and Mass Transfer, Antalya, Turkey, April 14-19, 2002.
  • Fedorov, A. and Viskanta, R., 1999, "Heat and Mass Transfer Dynamics in the Microchannel Adsorption Reactor", Microscale Thermophysical Engineering, Vol. 3, No. 2, pp. 111-140.
  • Fedorov, A. and Viskanta, R., 1999, "Scale Analysis and Parametric Study of Transient Heat/Mass Transfer in the Presence of Adsorption", Chemical Engineering Communications: International Journal, Vol. 171, pp. 231-257.
  • Fedorov, A. and Viskanta, R., 1999, "Analysis of Transient Heat/Mass Transfer and Adsorption/Desorption Interactions", International Journal of Heat and Mass Transfer, Vol.42, No.5, pp.803-820.
  • Fedorov, A. and Viskanta, R., 1998, "Heat/Mass Transfer and Adsorption Dynamics in a Honeycomb Adsorbent: Application of the Simplified Local Density Model", Thermal Science and Engineering, Vol.6, No.1, pp.1-10.
  • Fedorov, A. and Viskanta, R., 1997, "Heat and Mass Transfer Aspects of Gas Separation by Adsorption", Thermal Science and Engineering, Vol.36, No.140, pp.4-11.
  • Rabovitser, J., Chudnovsky, Ya., Matsui, K., Viskanta, R., and Fedorov, A., 1998, "Development of a Compact High Efficiency and Low Emission Surface Combustor-Boiler", International Gas Research Conference, San Diego, California, USA.
  • Degertekin, F.L. and Fedorov, A. G., "Integrated Micro Fuel Processor and Flow Delivery Infrastructure," U.S. Patent #7,312,440 (2007).
  • Fedorov, A. G. and Damm, D. L., "Hydrogen-Generating Reactors and Methods", U.S. Patent App. 11/708,772 (2007).
  • Fedorov, A.G., Varady, M., and Degertekin, F. L., "Droplet Impingement Chemical Reactors and Methods of Processing Fuel", U.S. Patent App. 11/946,079 (2007).
  • Fedorov, A. G., "Foldable Hydrogen Storage Media and Methods", U.S. Patent App. 11/713,375 (2007).

Project #2: Portable, Solid-State NanoReactor for Low Temperature, Energy Efficient Photocatalytic Disinfection of Air/Water Streams"

DESCRIPTION: This project focuses on a new approach to photocatalytic disinfection of air and water streams through the exploitation of the unique structural and optical properties of semiconductor oxide nanocatalysts incorporated into the light trapping pores of porous silicon. This approach to photocatalysis could potentially pave the way to the development of a uniquely powerful technology for reliable, energy efficient, and inexpensive destruction of a large group of pathogenic bacteria, viruses, protozoa, and fungi which can present a significant threat to society. Of no lesser importance is that the developed technology will be scalable and suitable for integration with existing air/water purification systems for personal (e.g., emergency workers and military personnel) and stationary (e.g., hospitals and residential buildings) use. The porous silicon (PS) structure (see left figure) whose micron-size open pores are decorated by clusters of silica or titania nanospheres 5-30 nm in diameter (see middle figure), by themselves or impregnated with a noble metal, forming appropriate size photocatalyst quantum dots (QD), constitute a conceptually novel heterogeneous photocatalytic microreactor with possible superior performance (see right figure). Its success is based on four factors. First, micro-PS can provide a uniform and highly effective (i.e., tightly localized) illumination of the photocatalyst everywhere using the UV-VIS light generated through PS electroluminescence or photoluminescence. Second, PS, especially in the form of a hybrid macroporous-nanoporous structure, can provide a large specific (i.e., per unit volume) surface area, owing to its highly porous structure and enhanced by the additional surface area made available via attached catalyst-based nanostructures. Third, photocatalysts in the form of nanoparticles have been shown to often possess superior catalytic properties as compared to a conventional bulk catalyst by virtue of the electronic modification of the catalyst through size quantization . Finally, because of the small characteristic size of the PS pores forming the reactor flow network, we can essentially eliminate diffusion limitations (~1/D^2, where D is the pore diameter) on the rate of the heterogeneous chemical reaction. This mode can achieve reaction kinetics at its intrinsic rate while maintaining sufficient reactor throughput using parallel chemical processing in many identical reactor units.

Our current efforts include: (1) using porous silicon with a well-controlled geometry and surface chemical composition which, at the same time, acts as a light-trapping and reactor-supporting structure and as an internal light source for photocatalysis as we exploit its luminescence; (2) producing TiO2-xNx, silica (SiO2), and SiO2-xNx nanospheres and agglomeration within the micropores of the PS reactor to form photocatalyst quantum dots, (3) gold impregnating these nanostructures using surface-hydroxyl group-metal complexation and coating the nanostructures using electroless deposition techniques to enhance the quantum efficiency of photooxidation , (4) characterizing experimentally the PS photocatalytic reactor and its key elements, and (5) demonstrating reactor performance using selected model analytes.

SPONSOR: NSF NIRT (current)

COLLABORATION: Prof. James Gole (GT Physics), Drs. Mark King and Susan Ray (Emory Medical School and Grady Hospital)

STUDENTS: Andrew Ogden (Ph.D.)

RELEVANT PUBLICATIONS/PATENTS:

  • Ogden A., Corno, J. A., Hong, J.-I., Fedorov A., and Gole, J.L., Maintaining particle size in the transformation of anatase to rutile titania nanostructures, J. Phys. Chem. Solids, 69 (11), 2898-2906 (2008).
  • Ogden, A., Gole, J.L., and Fedorov, A., Optical and electronic properties of semiconducting nanostructures for photocatalytic hydrogen production, J. Nanoelectronics & Optoelectronics, 2 (3), 269-277 (2007) invited.
  • Kumar S., Fedorov, A. G., and Gole, J. L., 2005, "Photodegradation of ethylene using visible light responsive surfaces prepared from titania nanoparticle slurries", Applied Catalysis B: Environmental, Vol. 57, No. 2, pp. 93-107.
  • Gole, J.L., Lewis, S. E., and Fedorov, A., From nanostructures to porous silicon: sensors, photocalalytic microreactors, and battery electrodes, SPIE Symposium on Optics & Photonics: Conference on "Physical Chemistry of Interfaces and Nanomaterials IV", San Diego, CA, July 31-August 4, 2005 (invited paper).
  • Gole, J. L., Fedorov, A., Hesketh, P., and Burda, C., 2004, "From nanostructures to porous silicon: sensors and photocatalytic reactors", Physica Status Solidi (c), Vol. 1, No. S2, pp. S188-S197.
  • Gole, J.L., Burda, C., Fedorov, A., and Prokes, S., 2003, "Highly efficient formation of TiO2-xNx-based photocatalysts - Potential application in microreactors, sensors, and photovoltaics", Materials Research Society Symposium Proceedings, Vol. 789, Paper N 12.7.
  • Gole, J.L., Burda, C., Fedorov, A., and White, M., 2003, "Enhanced reactivity and phase transformation at the nanoscale: efficient formation of active silica and doped and metal seeded TiO2-xNx photocatalysts", Review of Advances in Materials Science, Vol. 5, pp. 265-269.
  • Gole, J.L., White, M., Fedorov, A., and Burda, C., "Efficient Formation of Active Silica and Doped and Metal Seeded Titania for Visible Light Tunable Photocatalysis: Application to Microreactors, Solar Cells, and Sensors", Proceedings of the 133rd TMS Annual Meeting and Exhibition, Charlotte, North Carolina, March 14-18, 2004 (invited).
  • Fedorov, A. G., Gole J., and Phillips, C., "From Energy to Environment: Unique Opportunities for Nanoscale Catalysis", in Proceedings of NanoTherm: US-Japan Seminar on Nanoscale Thermal Science & Engineering, Berkeley, California (June 24-26, 2002).
  • Gole, J. L., Lewis, S., Hesketh, P., and Fedorov, A., "Sensing and Photocatalysis for a Combined Nano/Microporous Array Enhanced with Nanocrystalline Semiconductor Coatings", in Proceedings of Materials Research Society (MRS) Fall 2002 Meeting, Boston, Massachusetts (December 2-6, 2002).
  • Fedorov, A. G. and Gole, J., "Photocatalysis Using Nanostcuctured Porous Silicon", Patent Pending.

Project #3 : "Fluid Mechanics, Mass Transport, and Electrochemistry of Biochemical Interface Imaging Using AFM-Integrated Scanning Electrochemical and Optical Nanoprobes"

DESCRIPTION: The present project focuses on an innovative multidimensional approach for the investigation of cell communication processes at the molecular level. In this project, novel, innovative and interdisciplinary research is emphasized with focus on the application of integrated scanning nanoprobe sensing systems. Scanning probe microscopy (SPM) techniques provide powerful means for obtaining chemical, topographical and optical information with high spatial resolution. Each technique - atomic force microscopy (AFM), scanning nearfield optical microscopy (SNOM) and scanning electrochemical microscopy (SECM) - is designed to provide a specific kind of data. To date, none of these individual techniques provide simultaneous information with high selectivity and sensitivity on multiple parameters correlated in space and time, information required for in situ investigations of complex biological systems and heterogeneous matrices.

In collaboration with Professor Mizaikoff's group at GT Chemistry, we work on developing the combinations of SECM-SNOM and SECM-AFM-SNOM, along with inverted confocal microscopy and IR spectroscopy, and investigate the application of these combined techniques for localization of exocytotic events at the cell surface. With the developed instrumentation, a unique set of multiple analytical parameters correlated in space and time will be obtained, which is critical to the investigation of complex biosystems and biological processes. Our part in this project is in development of process simulation and visualization tools for quantitative interpretation of the nanoprobe images.

The mathematical modeling and simulation of the electrochemical and physical processes taking place during the scanning process is essential for optimizing the design of integrated SECM-AFM scanning nanoprobes, as well as for interpretation of the imaging data. A dynamic electrochemical process involves the transport of reactants (reduced and oxidized species) and their intermediates between a metal electrode and a studied conducting or insulating substrate/interface. This includes adsorption/desorption of reactants, surface diffusion and phase formation, interfacial electron transfer(s), and possibly homogeneous reactions in the solution. During the experimental study of reaction kinetics and mechanisms, the challenge is to identify quantitatively the relative importance of each of these steps. Accordingly, quantitative interpretation of the experimental results demands rigorous modeling of the underlying physicochemical phenomena. The key feature of dynamic electrochemistry is that the mass flux of reactants at the electrode/solution interface is a direct measure of the interfacial reaction rate and, if the mass transport is sufficiently high and well defined (i.e., calculable), the kinetics of the interfacial and/or solution processes can be measured unambiguously. Thus, a carefully validated mathematical model of the mass transport process should become the key tool for quantitative evaluation of the cellular events investigated in the project.

The complex transport phenomena underlying SECM-AFM require visualization of multiple dependent variables (e.g., ion concentrations, velocity components, tip current, and others) recorded on the multitude of spatial and time scales, and the commercial visualization software programs are generally not able to provide satisfactory environment to handle such multivariable-multiscale datasets in an integrated framework. To this end, we propose to develop an interactive, hierarchical data flow visualization tool capable of visualizing and comparing the data obtained using macroscale continuous simulations and that from the microscale (atomic) level simulations by building on our latest advances in this area.

SPONSOR: NSF (completed), NIH (current)

COLLABORATION: Dr. Christine Kranz, Prof. Boris Mizaikoff (GT Chemistry), Prof. Doug Eaton (Emory)

STUDENTS: Audric Saillard (M.S.), Youg Koo Kwon (Ph.D.), Dr. Vladimir Zarnitsyn (Post-doc), and Dr. Peter Kottke (Post-doc)

RELEVANT PUBLICATIONS:

  • Zarnitsyn, V. and Fedorov, A., Mechanosensing using drag force for imaging soft biological membranes, Langmuir, 23 (11), 6245-6251 (2007).
  • Kottke, P. A., Saillard, A., and Fedorov, A., 2006, Droplet growth and transition to coalescence in confined geometries, Langmuir, Vol. 22(13), 5630-5635.
  • Kottke, P. A. and Fedorov, A., 2005, Advective and transient effects in combined AFM/SECM operation, J. Electroanal. Chem., Vol. 583, No. 2, pp. 221-231.
  • Kottke, P. A. and Fedorov, A., 2005, Generalized principles of unchanging total concentration, J. Phys. Chem. B, Vol. 109, pp. 16811-16818.
  • Fan, T.-H., Mayle, T., Kottke, P., and Fedorov, A. G., 2006, "Simulation of Electroanalysis Using Boundary Element Method", Trends in Analytical Chemistry, Vol. 25 (1), pp. 52-65.
  • Fan, T. H. and Fedorov, A. G., 2004, "An Integrated Transport Model for Tracking Exocytotic Event Dynamics Using a Microelectrode", Analytical Chemistry, Vol. 76, pp. 4395-4405.
  • Fan, T. H. and Fedorov, A., "An Integrated Transport Model for Tracking of Individual Exocytotic Events Using a Microelectrode", Seventh Nanotechnology Conference and Trade Show NANOTECH 2004, Boston, Massachusetts, March 7-11, 2004.
  • Fan, T. H. and Fedorov, A. G., 2003, "Electrohydrodynamics and Surface Force Analysis in AFM Imaging of a Charged, Deformable Biological Membrane in a Dilute Electrolyte Solution", Langmuir, Vol. 19, pp. 10930-10939.
  • Fan, T. H. and Fedorov, A. G., "Electrohydrodynamic Interactions of an AFM Tip and a Biological Membrane", Sixth Nanotechnology Conference and Trade Show NANOTECH 2003, San Francisco, California, February 23-27, 2003.
  • Fan, T. H. and Fedorov, A. G., 2003, "Analysis of Hydrodynamic Interactions During AFM Imaging of Biological Membranes", Langmuir, Vol. 19, pp. 1347-1356.
  • Fan, T. H. and Fedorov, A. G., 2001, "Visualization of Atomic Force Microscopy from Molecular Dynamics Simulations", ASME Journal of Heat Transfer, Vol. 123, pp. 619.

Project #4 : "Model-Based Optimal Design of (Bio)Chemical Sensors and Microfluidic Drug/Gene Delivery Devices"

DESCRIPTION: In this project, a model-based methodology for optimal design of polymer coated chemical sensors is developed and is illustrated for the example of infrared evanescent field chemical sensors. The methodology is based on rigorous and computationally efficient modeling of combined fluid mechanics and mass transfer. A simple algebraic equation for the optimal size of the sensor flow cell is developed to guide sensor design and validated by extensive CFD simulations. Based upon these calculations, optimized geometries of the sensor flow cell are proposed to further improve the response time of chemical sensors.

Independent of the specific transduction mechanism, all chemical sensors generate signals upon molecular interaction of their selective chemical recognition interface with the desired target analyte. To increase the detection threshold, the analyte of interest is usually preconcentrated by various techniques, utilizing hydrophobic polymer layers as preferred implementation in many sensing applications operated in aqueous environments. In depth understanding of analyte enrichment in the polymers due to bulk solvation effects has been a major issue of physical and analytical chemistry over several decades prompted. In the chemical sensing community, major efforts have recently been invested into modeling and optimization of polymer-based enrichment layers, whereas optimization of the sensor flow cell geometry and mass transport was almost completely untouched. This is a surprising fact, in particular since data acquisition for chemical sensors can be a complex process; thus, appropriate simulation models of chemical sensors can serve as highly valuable tool for sensor design and data interpretation.

During decade only few relatively simplistic models have been developed for different types of chemical sensors, ranging from fiber-optic chemical sensor to dopamine biosensor and thermoelectric gas sensors. It is widely believed that miniaturization of the cross-sectional area of the sensor flow cell results in reduction of the response time, as well as threshold of detection. This "intuitive" rule-of-thumb is questioned in this project, aiming at establishing a sound theoretical basis for optimal design of the flow cell for polymer coated chemical sensors. In addition, multicomponent mass transfer effects are rigorously modeled to establish validity limits for commonly used pseudo-binary diffusion approximation for treating mixtures containing multiple analytes of interest.

SPONSOR: ALCOA Fellowship & GT Research Foundation (completed)

COLLABORATION: Prof. Boris Mizaikoff (GT Chemistry), Prof. Gole (GT Physics), Prof. Charlie Hao (Emory/Winship Cancer Institute), and Drs. Mark Papania and Rotta (CDC).

STUDENTS: Cynthia Phillips (M.S.)

RELEVANT PUBLICATIONS/PATENTS:

  • Kottke, P. A., Fedorov, A.G., and Gole, J. L., Multiscale transport in porous silicon gas sensors, In Modern Aspects of Electrochemistry, 43/44, M. Schlesinger (Editor), Springer, 2007 (invited).
  • Zarnitsyn, V., Meacham, J. M., Varady, M., Hao, C., Degertekin, F. L., and Fedorov, A., Electrosonic ejector microarray for drug and gene delivery, Biomedical Microdevices, 10 (2), 299-308 (2008).
  • Kottke, P. A., Kranz, C., Kwon Y-K, Masson, J.-F., Mizaikoff, B. M., and Fedorov, A., Theory of polymer entrapped enzyme ultramicroelectrodes: Fundamentals, J. Electroanal. Chem., 612 (2), 208-218 (2008).
  • Kottke, P. A., Kranz, C., Kwon Y-K, Masson, J.-F., Mizaikoff, B. M., and Fedorov, A., Theory of polymer entrapped enzyme ultramicroelectrodes: Application to glucose and adenosine triphosphate detection, J. Electroanal. Chem., 618 (1/2), 74-82 (2008).
  • Phillips, C. and Fedorov, A., 2004, "Multicomponent Mass Transfer in Polymer-Coated Chemical Sensors", Sensors & Actuators B, Vol. 99, No. 2-3, pp. 273-280.
  • Phillips, C., Jakusch, M., Steiner, H., Mizaikoff, B., and Fedorov, A., 2003, "Model-based Optimal Design of Polymer Coated Chemical Sensors", Analytical Chemistry, Vol. 75, No. 5, pp. 1106-1115.
  • Fedorov, A. G. and Degertekin, F. L., "Electrosonic Cell Manipulation Device and Methods of Use Thereof", U.S. Patent App. 11/277,662 (2006).

Project #5 : "Thermal Management of Next Generation Terascale Integrated Circuits and Interconnects"

DESCRIPTION: Thermal management is a systems issue, spanning several orders in length scales from the interconnects and transistors to an entire data center. The industry has traditionally addressed these issues in segments, isolating the junction-to-case thermal management problem from the case-to-ambient problem, etc. This situation prevents truly optimal system-level solutions and consumes the entire chip backside for thermal management using bulky metal heat sinks and fans, making it difficult to develop novel strategies that release surface area for optical and RF I/O. The ITRS projects high performance single chip powers to approach 288 W by 2012, which yields heat fluxes that simply cannot be accommodated using this disjointed approach. Furthermore, the integration of multiple circuit functionalities onto a single chip, i.e., RF, optical, CMOS, MEMS, etc., the demands for highly localized temperature control and hotspot cooling cannot be accommodated using a traditional package centric approach. The best approach for satisfying the future needs is to use a multiscale integrated approach. These imply heat fluxes of ~100 W/cm2 at the chip level and 10 kW/ft2 at the data center floor level. For the portables, while the heat fluxes are lower, the space and battery power constraints, as well as the more stringent touch temperature limits are driving a search for new solutions. Along with the increase in power, there are a number of other emerging trends driving the need for unique thermal solutions: (i) Highly non-uniform power dissipations on the CPU chip due to integration of cache memory with the processor, (ii) Partial or no access to the top surface of the die due to optical interconnects, (iii) Increasing importance of Joule heating in interconnects.

The focus of our current efforts is on the development and assessment of three classes of thermal management devices for both stationary high performance and portable systems. The single phase and phase-change based micro and nano fluidic schemes are being developed that effectively utilize through-the-board thermal pathways. Additionally, schemes for the effective delivery and utilization of liquefied air in an open loop flow arrangement to achieve both effective thermal management, as well as the performance benefits of low temperature operation are being explored. We also explore the use of carbon nanostructures for localized chip-centric thermal management and mist impingement cooling at the chip level using micromachinned ultrasonic acoustic atomization.

SPONSOR: Interconnect Focus Center/MARCO/DARPA (current)

COLLABORATION: Prof. Yogendra Joshi (GT ME), Prof. Paul Kohl (GT ChE), Prof. J. Meindl (GT ECE)

STUDENTS: Stephane Launay (Post-doc), Xianjin Wei (Post-doc), Prajesh Bhattacharya (Post-doc), Yoon Jo Kim (Post-doc), Shivesh Suman (Ph.D.), Robert Wadell (M.S.), Shankar Narayanan (Ph.D.), Vivek Sahu (M.S.)

RELEVANT PUBLICATIONS/PATENTS:

  • Joshi, Y., Fedorov A. G., Wei, X., and Gurrum, S. P. Limits of current heat removal technologies and opportunities, In Integrated Interconnect Technologies for 3D Nanoelectronic Systems, M. Bakir & J. Meindl (Editors), Artech House, 2007 (invited).
  • Narayanan, S., Fedorov, A., and Joshi, Y., On-chip thermal management of hot spots using a perspiration nanopatch, J. Micromech. Microeng., in review (2010).
  • Fedorov, A. and Meacham, J. M., Evaporation-enhanced, dynamically-adaptive air (gas)-cooled heat sink for thermal management of high heat dissipation devices, IEEE Trans. Comp. Pack. Tech., 32 (4), 746-753 (2009).
  • Kim, Y. J., Joshi, Y., and Fedorov, A., Lee, Y. J., and Lim, S. K., Thermal characterization of interlayer microfluidic cooling of three-dimensional IC with non-uniform heat flux, ASME J. Heat Transfer, in press (2009).
  • Green, C., Fedorov, A., and Joshi, Y., Scaling analysis of performance trade-offs in electronics cooling, IEEE Trans. Comp. Pack. Tech., 32 (4), 868-875 (2009).
  • Green, C., Fedorov, A., and Joshi, Y., Fluid-to-fluid spot-to-spreader (F2/S2) hybrid heat sink for integrated chip-level and hotspot-level thermal management, ASME J. Electronic Packaging, 131 (2), 025002-09 (2009).
  • Kim, Y. J., Joshi, Y., and Fedorov, A., Thermally dependent characteristics and spectral hole burning of double-lasing quantum-dot laser, J. Appl. Phys., in review (2008).
  • Sahu, V., Joshi, Y., and Fedorov, A., Hybrid solid state/fluidic cooling for hot spot removal, Nanoscale Microscale Thermophys. Eng., in press (2009).
  • Narayanan, S., Fedorov, A., and Joshi, Y., Gas-assisted thin-film evaporation from confined spaces for dissipation of high heat fluxes, Nanoscale & Microscale Thermophys. Eng., 13 (1), 30-53 (2009).
  • Fedorov, A. and Meacham, J. M., Evaporation-enhanced, dynamically-adaptive air (gas)-cooled heat sink for thermal management of high heat dissipation devices, ITherm 2008, Orlando, Florida, USA May 28-31, 2008.
  • Sahu, V., Fedorov, A., and Joshi, Y., Hybrid solid-state/fluidic cooling for hot spot removal, ITherm 2008, Orlando, Florida, USA May 28-31, 2008
  • Green, C., Fedorov, A., and Joshi, Y., Fluid-to-fluid spot-to-spreader (F2/S2) hybrid heat sink for integrated chip-level and hotspot-level thermal management, ITherm 2008, Orlando, Florida, USA May 28-31, 2008.
  • Narayanan, S., Fedorov, A., and Joshi, Y., Perspiration nanopatch for hot spot thermal management, InterPack'2007, Vancouver, BC, Canada, July 8-12, 2007.
  • Coggins, C., Gerlach, D., Joshi, Y., and Fedorov, A., Scaling of single- and multiple-stage cascaded vapor compression refrigeration systems for electronics cooling, Int. J. Refrigeration, in review (2007).
  • Suman, S., Fedorov, A., and Joshi, Y., Thermodynamic design of a compact thermal compressor for sorption assisted cryogenic cooling of electronics, Int. J. Refrigeration, in review (2007).
  • Kim, Y. J., Joshi, Y., Fedorov, A., An absorption based miniature heat pump system for electronics cooling, Int. J. Refrigeration, 31 (1), 23-33 (2007).
  • Kim, Y. J., Joshi, Y., Fedorov, A., Performance analysis of air-cooled microchannel absorber in absorption based miniature electronics cooling system, KSME J. Mech. Sci. Tech., in press (June 2007).
  • Wadell, R., Joshi, Y., and Fedorov, A., Experimental investigation of compact evaporators for ultra low temperature refrigeration of microprocessors, ASME/IEEE J. Electronic Packaging, 129 (3), 291-299 (2007).
  • Launay, S., Fedorov, A., Joshi, Y., Cao, A., and Ajayan P., Hybrid micro-nano structured thermal interface for pool boiling heat transfer enhancement, Microelectronics J., 37 (11), 1158-1164 (2006).
  • Gurrum, S., Suman, S., Joshi, Y., and Fedorov, A., 2004, Thermal issues in next generation integrated circuits, IEEE Transactions on Device and Materials Reliability, Vol. 4, No. 4, pp. 709-715 (invited paper).
  • Naeemi, A., Joshi, Y., Fedorov, A., Kohl, P., and Meindl, J.D., The urgency of deep sub-ambient cooling for gigascale integration, International Conference on Integrated Circuit Design and Technology ICICDT05, Austin, Texas, May 9-11, 2005.
  • Suman, S., Fedorov, A., and Joshi, Y., Thermodynamic design of thermal compressor for sorption assisted cryogenic cooling of electronics, InterPack 05, San Francisco, CA, July 17-22, 2005.
  • Launay, S., Fedorov, A., Joshi, Y., Cao, A., and Ajayan, P. M., Hybrid Micro-Nano Structured Thermal Interface for Pool Boiling Heat Transfer Enhancement, THERMINICS - International Workshop on Thermal Investigations of ICs and Systems, Sophia Antipolis, Ctte d'Azur, France, September 29-October 1, 2004.
  • Suman, S., Fedorov, A., and Joshi, Y., Cryogenic Cooling of Electro nics: Revisited, ITherm 2004, Las Vegas, Nevada, June 1-14 2004.
  • Fedorov, A. and F. L. Degertekin, Micromachined Acoustic mu-Atomizer for Mist Impingement Cooling of High Performance Electronics, ONR Thermal Management Workshop, Naval Thermal Task Force (NAFTTAF), US Naval Academy, Annapolis, Washighton, USA (April 8, 2003).
  • Gurrum, S., Suman, S., Joshi, Y., and Fedorov, A., Thermal issues in next generation integrated circuits, International Electronic Packaging Technical Conference and Exhibition, Maui, Hawaii, July 6-11, 2003.
  • Fedorov, A. and Viskanta, R., 2000, "Three-Dimensional Conjugate Heat Transfer in the Microchannel Heat Sink for Electronic Packaging", International Journal of Heat and Mass Transfer, Vol. 43, pp. 399-415.
  • Fedorov, A. and Viskanta, R., 1999, "Analysis of Conjugate Heat Transfer in a Three-Dimensional Microchannel Heat Sink for Cooling of Electronic Components", International Mechanical Engineering Congress and Exposition IMECE'99, Nashville, Tennessee.
  • Fedorov, A. and Viskanta, R., 1997, "A Numerical Simulation of Conjugate Heat Transfer in an Electronic Package Formed by Embedded Discrete Heat Sources in Contact with a Porous Heat Sink", ASME Journal of Electronic Packaging, Vol. 119, pp. 8-16.
  • Fedorov, A. G., Wadell, R., and Launay, S., "Vortex Tube Refrigeration Systems and Methods", U.S. Patent App. 11/105,833 (2005).
  • Launay, S., Fedorov, A. G., and Joshi, Y., "Thermal Management Devices, Systems, and Methods", U.S. Patent 7,532,467, Issued 06/2009.
  • Fedorov, A. G., "Fluid-to-Fluid Spot-to-Spreader Heat Management Devices and Systems and Methods of Managing Heat ", U.S. Patent App. 60/954,360 (2007).
  • Fedorov, A. G., "Nano-Patch Thermal Management Devices, Methods, and Systems", U.S. Patent 7,545,644, Issued 06/2009.
  • Fedorov, A. G., "Evaporation-Enhanced Thermal Management Devices, Systems, and Methods of Heat Management ", U.S. Patent App. 12/215,320 (2008).
  • Fedorov, A. G., "Thermal Ground Planes, Thermal Ground Plane Structures, and Methods of Heat Management", U.S. Patent App. 12/331,579 (2008).

Project #6 : "Electron, Mass, and Heat Transport in E-Beam and Laser-Jet Chemical Vapor Deposition of Nanostructured Materials and Thin Film Coatings"

DESCRIPTION: In this project, we would like to determine via experimentation and thermal/mass transport analysis the conditions required for controlled growth of patterned arrays of carbon nanotubes and nanofibers. The influence of temperature, reagent flow rate concentration, and catalyst/substrate type will be investigated using statistically designed and analyzed experiments. Temperature is often the most significant process variable for any form of CVD, including Combustion (CCVD) and Laser (LCVD), and its measurement has been particularly troublesome in LCVD because of the small size of the heated spot.

Optimization and precise control of the shape and mechanical properties of deposited nanostructures can be achieved only if the transport phenomena underlying the gas-jet LCVD process are fundamentally understood and appropriate simulation tools are developed and experimentally validated. The complexity of the physical situation is underscored by the fact that CCVD and LCVD are truly multiphysics and multiscale processes. They includes jet impingement convective heat and mass transfer, heat transfer by conduction within a substrate, radiation heat transfer between the substrate and the reactor walls, and finally the homogeneous and heterogeneous chemical reactions on the substrate resulting in material deposition and accompanied by the volumetric heat release. Since the deposition rates follow an Arrhenius relationship that is exponential with respect to temperature, it is critical to understand and quantify the local temperature field in the vicinity of the deposition spot. In a laser-heated process such as pyrolytic LCVD, the temperature field not only varies by an order of magnitude over the diameter of the laser spot (i.e., a micrometer scale),4 but it is also directly influenced by the heat transfer processes occurring on the reactor macroscale (i.e., a meter scale)5. This example signifies the importance as well as the challenges of the multiscale integrated thermal/fluid modeling of the CVD process.

Over the past few years, we have developed the series of models of increasing complexity based on the Navier-Stokes equations of motion to simulate the fluid flow, thermal, and concentration fields in the LCVD reactor. Our on-going efforts focus on including the effect of surface-grown nanostructures on the modification of the surface radiadive properties of the substrate during deposition process as well as on rigorous modeling of radiative transfer in the CVD chamber.

SPONSOR: NSF NIRT (current), SRC Nanomanufacturing (current).

COLLABORATION: Profs. Jack Lackey (GT ME), Thom Orlando (GT Chem), and ZL Wang (GT MSE)

STUDENTS: Ben White (M.S.), Matt Henry (Ph.D.) and Konrad Rykaczewski (Ph.D.)

RELEVANT PUBLICATIONS:

  • Rykaczewski, K., Hildreth, O.J., Kulkarni, D., Henry, M., Kim, S-K., Wong, C.P., Tsukruk, V. V., and Fedorov, A., Maskless and resist-free rapid prototyping of three dimensional silicon structures through Electron Beam Induced Deposition (EBID) of carbon in combination with Metal assisted Chemical Etching (MaCE) of Silicon, Nano Lett., in review (2009).
  • Rykaczewski, K., Henry, M., Kim, S-K., Fedorov, A., Kulkarni, D., Singamaneni, S., and Tsukruk, V. V., Effect of electron beam induced deposited (EBID) carbon joint geometry and material properties on electrical resistance of multiwalled carbon nanotube (MWNT)-to-metal contact interface, Nanotechnology, 21, 035202-035214 (2010).
  • Rykaczewski, K., Henry, M., and Fedorov, A., Electron beam induced deposition of residual hydrocarbons in the presence of a multiwall carbon nanotube, Appl. Phys. Lett. , 95 (11), 113112-113115 (2009).
  • Rykaczewski, K., Marshall, A., White, W.B., and Fedorov, A., Dynamic growth of carbon nanopillars and nanorings in electron beam induced dissociation of residual hydrocarbons, Ultramicroscopy, 108, 989-992 (2008).
  • Fedorov, A., Rykaczewski, K., and White, W., Transport issues in focused electron beam chemical vapor deposition, Surface & Coatings Tech., 201, pp. 8808-8812 (2007).
  • White, W.B., Rykaczewski, K., and Fedorov, A., What controls deposition rate in electron beam chemical vapor deposition?, Phys. Rev. Lett., Vol. 97(8), pp. 086101-4 (2006).
  • Rykaczewski, K., White, W.B., and Fedorov, A., Analysis of electron beam induced deposition (EBID) of residual hydrocarbons in electron microscopy, J. Appl. Phys. A, 101 (5), 054307-054319 (2007).
  • Johnson, R. W., Duty, C. E., Fedorov, A., and Lackey, W. J., Computational modeling of forced flow laser chemical vapor deposition, J. App. Phys. A, 90 (2), 333-345 (2008).
  • Jiang, M., Fedorov, A. G., and Lackey, W. J., 2004, "Liquid Reagent CVD of Carbon: Kinetic Experiments and Heat and Mass Transport Analysis", Carbon, Vol. 42, No. 10, pp. 1901-1906.
  • Duty, C., Johnson, R., Gillespie, J., Fedorov, A. G., and Lackey, J., 2002, "Heat and Mass Transfer Modeling of an Angled Gas-Jet LCVD System", Journal of Applied Physics A, Vol. 76, pp. 1-9.
  • Malikov, G. K., Lobanov, D. L., Malikov, K. Y., Lisienko, V. G., Viskanta, R., and Fedorov, A., 2001, "Direct Flame Impingement Heating for Rapid Thermal Materials Processing", International Journal of Heat and Mass Transfer, Vol. 44, No 9, pp. 1751-1758.
  • Malikov, G., Lobanov, D., Malikov, Y, Lisienko, V., Viskanta, R. and Fedorov, A., 1999, "Experimental and Numerical Study of Heat Transfer in a Flame Jet Impingement System", Journal of the Institute of Energy, Vol. 72, pp. 2-10.
  • Fedorov, A., Lee, K. and Viskanta, R., 1998, "Inverse Optimal Design of the Radiant Heating in Materials Processing and Manufacturing", Journal of Materials Engineering and Performance, Vol. 7, No. 6, pp. 719-726.
  • Fedorov, A. G. and Rykaczewski, K., "Electron Beam Induced Deposition of Interface to Carbon Nanotube", U.S. Patent App. 12/493,278 (2009).

Project 7: Scanning Mass Spectrometry (SMS) Probe and AMUSE (Array of Micromachined UltraSonic Electrospray) Ion Source for Mass Spectrometry

DESCRIPTION: Mass Spectroscopy (MS) has become the technology of choice to meet today's unprecedented demand for accurate bioanalytical measurements, including protein identification. Although MS can be used to analyze any biological sample, it must be first converted to gas-phase ions before it can be introduced into a mass spectrometer for analysis. It is transfer of a very small liquid sample (proteins are very expensive and often very difficult to produce in sizable quantities) into a gas-phase ions that is currently considered to be a bottleneck to high throughput proteomics.

Electrospray ionization (ESI) is a technique developed in early 1990th by Fenn (Noble Prize in Chemistry, 2002) to generate a spray gas-phase ions by applying high voltage (from several hundreds volts and up to a few thousands kilovolts relative to the ground electrode of the MS interface) to a small capillary through which the liquid solution is pumped. The high electric field ionizes the fluid forming the converging cone of the exiting jet which eventually breaks into many small droplets when the repulsive Coulombic forces overcome the surface tension. Because of the focusing effect associated with the spraying the electrically charged fluid, the size of the electrospray cone and thus of the formed droplets is in a few tens of nanometers range although the inner diameter of the capillary is in the micrometer range.

We are developing a unique drop-on-demand electrospray chip that utilizes the ultrasonic waves to drive the flow and capable of operating with the smallest reagent samples, resulting in the highest sensitivity, and potentially requiring much lower voltages for efficient ionization. The electrospray generation microchip relies on our patented MEMS based ultrasonic aerosolizing technology and offers potentially low-cost, disposable solution to the problem of producing charged liquid droplets of size and uniformity required for effective protein analysis. Further, since Taylor cone formation is not required for atomization in the proposed device, potentially much lower operating voltages would be needed for ion formation, leading to much gentler atomization process and reduction in molecule fragmentation. Our initial experiments demonstrate possible ion formation at applied voltages of the order of 100V rather than 1-4 kV required for conventional electrospray sources. Further, an array of individually addressable electrodes can be used for actuation of each droplet generator in the array separately, therby allowing multiplexing and parallel analysis of multiple analyte samples requiring different electric potential for ionization.

SPONSOR: NIH (current), NSF (current)

COLLABORATION: Profs. F. Levent Degertekin (GT ME), Facundo Fernandez (GT Chemistry), and David Muddiman (NCSU & Mayo Clinic)

STUDENTS: Tom Forbes (Ph.D.)

RELEVANT PUBLICATIONS/PATENTS:

  • Forbes, T. P., Degertekin, F.L., and Fedorov, A., Electrohydrodynamics of charge separation in droplet-based ion sources with time-varying electrical and mechanical actuation, J. Am. Soc. Mass Spec., in press (2009).
  • Kottke, P.A., Degertekin, F.L., and Fedorov, A., The Scanning Mass Spectrometry Probe: a scanning probe electrospray ion source for imaging mass spectrometry of submerged interfaces and transient events in solution, Anal. Chem., 82 (1), 19-22 (2010).
  • Forbes, T. P., Dixon, R. B., Muddiman, D.C., Degertekin, F.L., and Fedorov, A., Characterization of charge separation in the Array of Micromachined UltraSonic Electrospray (AMUSE) ion source for mass spectrometry, J. Am. Soc. Mass Spec., 20, 1684-1687 (2009).
  • Hampton, C.Y., Silvestri, C. J., Forbes, T.P., Varady, M.J., Meacham, J.M., Fedorov, A., Degertekin, F.L., and Fernandez, F.M., Comparison of the internal energy deposition of Venturi-assisted electrospray ionization and a Venturi-assisted Array of Micromachined UltraSonic Electrosprays (AMUSE), J. Am. Soc. Mass Spec., 19, 1320-1329 (2008).
  • Hampton, C.Y., Forbes, T.P., Varady, M.J., Meacham, J.M., Fedorov, A., Degertekin, F.L., and Fernandez, F.M., Analytical performance of Array of Micromachined UltraSonic Electrosprays (AMUSE) coupled to ion trap mass spectrometry for the analysis of peptides and proteins, Anal. Chem., 79 (21), 8154-8161 (2007).
  • Forbes, T. P., Degertekin, F. L., and Fedorov, A., Multiplexed operation of a micromachined ultrasonic droplet ejector array, Rev. Sci. Instrum., 78 (10), 104101-104106 (2007).
  • Dixon, R. B., Muddiman, D. C., Hawkridge, A. M., and Fedorov, A., Probing the mechanism of an air amplifier using an LTQ-FT-ICR-MS and fluorescence spectroscopy, J. Am. Soc. Mass Spec., 18 (11), 1909-1913 (2007).
  • Fedorov, A., and Degertekin, F. L., Scanning mass spectrometry probe for biochemical imaging, IEE Electronics Letters, Vol. 42(14), pp. 793-794 (2006).
  • Aderogba, A., Meacham, J. M., Fernandez, F., Degertekin F. L., and Fedorov, A., 2005, "Nanoelectrospray Ion Generation for High Throughput Mass Spectrometry using a Micromachined Ultrasonic Ejector Array", Applied Physics Letters, Vol. 86, pp. 203110-203113 (Also published in Virtual Journal of Nanoscale Science & Technology -- Volume 11, Issue 20, May 23, 2005).
  • Meacham, J. M., Varady, M., Degertekin F. L., and Fedorov, A., 2005, "Droplet Formation and Ejection from a Micromachined Ultrasonic Droplet Generator: Visualization and Scaling", Physics of Fluids, Vol. 17, No. 10, pp. 100605-100613.
  • Meacham, J. M., Ejimofor, C., Kumar, S., Degertekin F. L., and Fedorov, A.G, 2004, "A Micromachined Ultrasonic Droplet Generator Based on Liquid Horn Structure", Review of Scientific Instruments, Vol. 75, No. 5, pp. 1347-1352.
  • Fedorov, A. G. and Degertekin, F.L., "Electrospray Systems and Methods", US Patent #7,208,727 (2007).
  • Fedorov, A. G. and Degertekin, F.L., "Electrospray Systems and Methods", US Patent #7,557,342 (2009).
  • Fedorov, A. G. and Degertekin, F. L., "Reverse-Taylor-Cone Ionization Systems and Methods of Use Thereof", U.S. Patent #7,411,182 (2008).
  • Fedorov, A. G., "Scanning Ion Probe Systems and Method of Use Thereof ", U.S. Patent #7,442,927 (2008).
  • Fedorov, A. G., "Confining/Focusing Vortex Flow Transmission Structure, Mass Spectrometry Systems, and Methods of Transmitting Particles, Droplets, and Ions", U.S. Patent #7,595,487 (2009).

Project X: Creativity and Rigor in Research: Could We Marry Them and How?

DESCRIPTION: The project title says it all...

If you would like your views on the topic to be presented here, feel free to send us relevant materials or a web link. We'll review the materials and post them here as long as we think your materials do contribute to healthy discussion on the topic. The current members of the MITf-Lab have a priviledge and responsibility to be the judges of relevance of your contribution.

SPONSOR: Foundation for Unfundable Science (current)

COLLABORATION: Students and post-docs at MITf-Lab

RELEVANT PUBLICATIONS:

  • Niels Bohr's Principle of Radical Conservatism: "Be conservative by sticking to well-established physical principles, but probe them by exposing their most radical conclusions"... from Kip S. Thorne, "Retrospective: John Archibald Wheeler (1911-2008)", Science, vol. 320, p. 1603, June 20, 2008.
  • Panel discussion "How to do research?" organized by GT Mechanical Engineering Graduate Student Association.
  • More to come in the near future, but no promises, as it is a truly difficult problem...
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