Shawn Litster-Mechanical Engineering - Carnegie Mellon University

Shawn Litster

Associate Professor, Mechanical Engineering

Address:
5000 Forbes Avenue
Scaife Hall 323
Pittsburgh, PA 15213
Phone: 412-268-3050
Fax: 412-268-3348

Bio

Professor Litster’s research focuses on sustainable energy conversion technologies that leverage nano- and micro-scale transport phenomena for enhanced performance and new functionality. He is particularly interested in research that combines electrochemistry and electrokinetics with the mechanical engineering fundamentals of fluid mechanics, heat and mass transfer, and design. Hydrogen fuel cell technology is poised to become an important bridge between sustainable energy resources and end-user services (i.e. transportation). Litster’s research addresses technical obstacles to wide-spread adoption of fuel cells, such as effectively utilizing the costly platinum catalyst used in the electrodes. Unique capabilities in his group include microstructured electrode scaffold diagnostics, which have enabled the first through-plane potential measurements through the thickness of operating fuel cell and aqueous battery electrodes. These measurements assist researchers in pinpointing the loss the mechanisms that reduce energy conversion efficiency as well as assist in elucidating fundamental phenomena. These experimental methods are combined with advanced computational models of the micro-/nano-scale phenomena to identify directions for future material and device development.

Professor Litster is also the PI for CMU’s nano-scale resolution X-ray computed tomography (nano-CT) facility, which is a unique user facility for visualizing the 3D internal structure of materials down to 50 nm resolution. X-ray nano-CT is a non-destructive method of obtaining high resolution 3D images of the complex, internal structure of materials and devices. The high resolution of 50 nm (16 nm voxels) is achieved using advanced X-ray optics, including a single capillary condenser and a Fresnel zone plate objective. With the use of the Zernike phase contrast mode, this system can achieve its high resolution even on materials with low atomic numbers; i.e. materials with low absorption contrast, such as organic materials and polymers.  As a non-destructive method that operates with ambient and controlled sample environments, nano-CT opens the door for new 4D imaging approaches for capturing the temporal evolution of a material’s 3D microstructure under applied stresses and chemical environments.

Education


B.Eng. 2004, University of Victoria

M.A.Sc. 2005, University of Victoria

Ph.D. 2008, Stanford University

Selected Publications

  • N. Siefert, S. Litster, "Exergy and economic analyses of advanced IGCC–CCS and IGFC–CCS power plants," Applied Energy, 107,  315–328, (2013).
  • I.V. Zenyuk, E.C. Kumbur, S. Litster, “Deterministic Contact Mechanics Model Applied to Electrode Interfaces in Polymer Electrolyte Fuel Cells and Interfacial Water Accumulation,” Journal of Power Sources, 241, 379-387 (2013).
  • N. Siefert, D. Shekhawat, S. Litster, D. Berry, “Molten Catalytic Coal Gasification with In situ Carbon and Sulfur Capture,” Energy & Environmental Science, 5, 8660-8672, (2012).
  • K.C. Hess, J.F. Whitacre, S. Litster, “In situ Measurements of Potential, Current and Charging Current Across an EDL Capacitance Anode for an Aqueous Sodium Hybrid Battery,” Journal of The Electrochemical Society, 159, A1351-A1359, (2012). 
  • I.V. Zenyuk, S. Litster “Spatially-resolved modeling of electric double layers and surface chemistry for the hydrogen oxidation reaction in water-filled platinum-carbon electrodes,” Journal of Physical Chemistry C, 116, 9862-9875, (2012).
  • W.K. Epting, J. Gelb, S. Litster “Resolving the Three-dimensional Micro-structure of Polymer Electrolyte Fuel Cell Electrodes using Nano-scale  X-ray Computed Tomography,” Advanced Functional Materials, 22, pp. 555-560, (2012).
  • W.K. Epting, S. Litster “Effects of an Agglomerate Size Distribution on the PEFC Agglomerate Model,” International Journal of Hydrogen Energy, 37, pp. 8505-8511 (2012).
  • K.C. Hess, W.K. Epting, S. Litster, “Spatially-resolved, in situ potential measurements through porous electrodes as applied to fuel cells,” Analytical Chemistry, 83, pp 9492–9498, (2011).
  • F. Kivanc and S. Litster, “Pumping with electroosmosis of the 2nd kind in mesoporous skeletons,” Sensors Actuators: B. Chemical, 151, pp. 394-401, (2011).