MEAM Seminar Series Spring 2013
Seminars are held on Tuesday mornings, with coffee at 10:30 am in the Levine Hall Mezzanine and the seminar beginning at 10:45 am in Wu and Chen Auditorium (unless otherwise noted).
To be added to the MEAM Events mailing list (which sends notifications regarding all departmental seminars and events) please email us at firstname.lastname@example.org.
Thursday, January 10
Towne Building, room 337, 1:30 pm
Sherry Liu, Assistant Professor Bioengineering and Orthopaedic Surgery, University of Pennsylvania
"Micro-imaging and the mechanical modeling of bone - from bench side to bed side"
Abstract: Trabecular bone, the most important bone type in
osteoporosis, consists of microscopic trabecular plates and rods. The
transition of trabecular plates into trabecular rods is the hallmark
of pathogensis of osteoporosis. Current three-dimensional (3D) morphological and finite element (FE) analysis techniques, in general, lack specific segmentations of individual trabecular plates and rods.
We have developed new 3D individual trabeculae segmentation (ITS) based morphological analysis techniques to decompose trabecular bone network into individual plates and rods and evaluate the structural property for each individual trabecula. We demonstrated the critical role of trabecular plates in determining the apparent mechanical properties of human trabecular bone. This technique was also applied
to clinical micro magnetic resonance images (MRI) and high resolution peripheral quantitative computed tomography (HR-pQCT) images to measure the microstructural properties of trabecular bone in
osteoporotic and control subjects and showed great promise as a clinical assessment of bone quality.
We and others have shown high-resolution clinical images as suitable for input into µFE models for assessing bone strength. Currently, the most common µFE modeling strategy is to convert each voxel from an image into a single finite element, creating three dimensional (3D) patient-specific models that can provide an accurate and direct estimate of bone’s mechanical competence such as stiffness or
strength. However, the simple voxel-to-element modeling strategy results in a very large model size and the computational costs to derive nonlinear mechanical properties of bone, such as yield strength
or failure load, for clinical use are prohibitively high. Using ITS technique to segment the trabecular bone structure into individual plates and rods, a specimen-specific plate and rod (PR) model was
developed by modeling each of these trabecular plates and rods as a single beam/shell element rather than as a collection of hundreds of 8-node brick elements. Notably, the clinical HR-pQCT image-based PR
models achieved major reductions in element number (>40-fold) and CPU time (>1,200-fold) and revealed significantly lower Young’s modulus and yield strength at the radius and tibia in postmenopausal fracture
subjects compared to controls. We conclude that this accurate nonlinear µFE prediction of HR-pQCT PR model, which requires only seconds of desktop computer time, has tremendous promise for clinical
assessment of bone strength.
Biography: Sherry Liu is an Assistant Professor in the Department of
Orthopaedic Surgery and Bioengineering at University of Pennsylvania.
Prior to joining UPenn, she was an associate research scientist
(2009-2011) in the Department of Medicine at Columbia University. She
earned her PhD in Biomedical Engineering from Columbia University in
2007. Her current research focuses on biological processes in bone
and on how they influence bone material, microstructural, and
biomechanical properties with aging, disease, and therapies.
Vivek Shenoy, Professor, Materials Science and Engineering, University of Pennsylvania
"Mechanotranduction in 3D microtissues: Modeling the role of geometry and stiffness"
Abstract: In this talk, I will discuss a fundamental morphological instability of constrained 3D microtissues induced by a positive chemomechanical feedback between actomyosin-driven contraction and the mechanical stresses arising from the constraints. Using a 3D model for mechanotransduction we find that perturbations in the shape of contractile tissues grow in an unstable manner leading to formation of "necks" where tensile stresses are sufficiently large to lead to the failure of the tissue by narrowing and subsequent elongation. The origin of the failure mechanism driven by active forces we report is distinct from the seemingly similar and well-studied necking phenomena observed in "passive" materials due to elastic softening. Here the instability is caused by the active contraction (extension) of the regions of the tissue where the mechanical stresses are smaller (greater) than the characteristic actomyosin stall stress of the tissue. The magnitude of the instability is shown to be determined by the level of active contractile strain, the stiffness of the ECM and the stiffness of the boundaries that constrain the tissue. A phase diagram that demarcates stable and unstable behavior of 3D tissues as a function of these material parameters is derived. The predictions of our model are verified by analyzing the necking and failure of normal human fibroblast (NHF) tissue constrained in a loop-ended dogbone geometry and cardiac microtissues constrained between microcantilevers. In the former case, the tissue fails first by necking of the connecting rod of the dogbone followed by failure of the toroidal loops in agreement with our 3D finite element simulations. In the latter case we find that cardiac tissue is stable against necking when the density of the extra cellular matrix is increased and when the stiffness of the supporting cantilevers is decreased, also in excellent agreement with the predictions of our model. By analyzing the time evolution of the morphology of the constrained tissues we have quantitatively determined the chemo-mechanical coupling parameters that characterize the generation of active stresses in these tissues. More generally, the analytical and numerical methods we have developed provide a quantitative framework to study the biomechanics of cell to cell interactions in complex 3D environments such as morphogenesis and organogenisis.
Biography: Vivek Shenoy received his Ph.D. in Physics from The Ohio State University in 1998 and served as a postdoctoral fellow for two years at Brown University before beginning his career at Brown as assistant professor of Engineering in 2000, reaching the rank of full professor in 2010.
Dr. Shenoy's numerous honors include a National Science Foundation CAREER Award (2000), the Richard and Edna Solomon Assistant Professorship (2002-2005) and the Rosenbaum Visiting Fellowship from the Isaac Newton Institute of Mathematical Science, University of Cambridge.
Dr. Shenoy is a world leader in the mechanics and physics of nanostructure formation. He has used rigorous analytical methods and multiscale modeling techniques, ranging from atomistic density functional theory to continuum methods, to gain deep physical insight into a myriad of important problems in materials science and mechanics. He has authored over 100 research publications, with papers in Science, Proceedings of the National Academy of Sciences, Nature and Nano Letters.
Dr. Shenoy's current research focuses on developing theoretical concepts and numerical methods to understand the basic principles that control the behavior of both engineering and biological systems. A significant challenge in modeling these systems is that important processes involve coupling of both small-scale (atomic or single molecule) phenomena and long-range (elastic, electromagnetic) interactions over length scales of hundreds of nanometers. The goal of his group's work is to address these issues by combining atomic scale simulation methods with continuum or mesoscale theories and by adapting insights from condensed matter physics, solid mechanics, chemistry, materials science and applied mathematics.
Leo Donner, Lecturer, Atmospheric and Oceanic Sciences Program, Princeton University
"Aerosols, Clouds, and Climate: The Global Modeling Challenge"
Abstract: Atmospheric aerosols are produced by both natural and human processes. Aerosols
impact weather and climate by absorbing and scattering radiative energy in the atmosphere
and by providing nuclei for activating liquid and ice particles in clouds. Anthropogenic
aerosols can change the properties of clouds, which play a large role in the atmospheric
energy balance, and thereby are important in climate change. Understanding and modeling cloud-aerosol interactions in the climate system are challenging because the important physical processes occur over an enormous range of space and time scales. Phenomena from the scale of aerosol and cloud particles to global scales are important and strongly interactive. This seminar will describe the key issues in studying
aerosol-cloud interactions in climate models, identify major physical processes important in
determining forcing of the climate system by cloud-aerosol interactions, and outline major
Biography: Leo Donner is a physical scientist at the National Oceanic and Atmospheric Administration (NOAA) Geophysical Fluid Dynamics Laboratory
(GFDL) in Princeton, New Jersey (1991- ) and a lecturer in the Department
of Geosciences and Program in Atmospheric and Oceanic Science at Princeton University (1993- ). He received his B.S. (Atmospheric Science) from the
University of Michigan, Ann Arbor (1978) and M.S. and Ph.D. (Geophysical
Sciences) from the University of Chicago (1981, 1983). Previous positions
have been with the National Center for Atmospheric Research (1983-1987) and the University of Chicago (1987-1991). His research deals with clouds and convection in the climate system, parameterization of clouds and convection in climate models, and the development of climate models. He co-chairs the Atmospheric Model Working Group for the National Science Foundation (NSF)/Department of Energy
(DOE) Community Climate System Model and served as science chair for the GFDL Atmospheric Model-3, which has been awarded a 2012 Group Gold Medal from the United States Department of Commerce. He is an affiliate scientist at the National Center for Atmospheric Research, a principal investigator for an NSF/NOAA Climate Process Team, and a member of the science team for DOE Atmospheric System Research. He has served as editor of Journal of Climate and chair of the University Corporation for
Atmospheric Research Board of Trustees, among numerous other national and international science panels and working groups.
Amos Avidan, Bechtel Corporation
"Nuclear Power Technology and Construction Trends"
Abstract: While energy demand in OECD countries is projected to grow slowly over the next 3 decades, demand in non-OECD countries is projected to more than double. Nuclear energy now supplies about 20% of electrical energy in the USA and about 14% worldwide. It is projected to grow globally at 2.4% a year through 2040, and currently there are 65 new plants under construction, most of them in Asia. I will discuss nuclear reactor technology trends, including the recent development of small modular reactors. I will also address some of the challenges of planning, engineering and constructing these complex projects.
Biography: Amos Avidan is a Senior Vice President and Bechtel's manager of Corporate Engineering and Technology. Amos was General Manager of Business Development and Technology for Bechtel Oil, Gas & Chemicals, Inc. (OG&C) till September, 2009. His previous assignments in Bechtel OG&C included Project Director of the Equatorial Guinea LNG project, and General Manager of Operations, LNG. Amos joined Bechtel in 2000, and was elected a Principal Vice President and a Bechtel Fellow in 2001. He was elected Senior Vice President in 2007. Prior to joining Bechtel, Amos was employed by Mobil Oil in a variety of assignments, including Manager of Catalytic Cracking, Manager of Upstream Surface Engineering, and VP of LNG technology. Amos has received a PhD degree in Chemical Engineering from the City University of New York in 1980 and is a licensed Professional Engineer in Texas. He has authored and co-authored more than 70 books and technical publications and 31 US patents. Amos has served as a director of the American Institute of Chemical Engineers (AIChE), and he is a Fellow of the AIChE. In 2009, Amos was elected to the US National Academy of Engineering.
Chang-Hwan Choi, Assistant Professor, Department of Mechanical Engineering, Stevens Institute of Technology
"Nature-Inspired Nano-Textured Surfaces: Design, Fabrications, and Applications"
Abstract: Nature, such as plants, insects, and marine animals, employs three-dimensional (3D) micro/nano-structures of regulated mechanical and chemical properties on their surfaces (e.g., leaves, wings, eyes, legs, and skins) for multi-purposes such as self-cleaning, low-friction, antifouling, and anti-frosting. Inspired by the nature, novel surfaces and materials have been engineered in numerous ways due to the recent advance of micro- and nanotechnologies. However, current manufacturing technologies are not sufficient yet to create such well-controlled small scale structures of precisely-defined structural three-dimensionality and hierarchy over a practically large surface area for various types of substrate materials. Such technical limitation has precluded the deeper understanding and the practical applications of such surfaces for various scientific and engineering applications. In this talk, the critical design parameters and nanofabrication methods for such multifunctional textured surfaces will first be introduced for various kinds of substrate materials. Such large-area 3D nanostructures with modulated structural dimensions and geometries can open new application possibilities in many areas. The rest of the talk will present a few examples of novel applications using the nano-engineered surfaces, especially for energy saving applications, including hydrodynamic drag reduction, anti-biofouling, and anti-icing.
Biography: Dr. Chang-Hwan Choi acquired his BS (1995) and MS (1997) in Mechanical & Aerospace Engineering from Seoul National University in Korea. He also earned his MS in Fluids, Thermal, and Chemical Processes from Brown University in 2002. Dr. Choi received his PhD in Mechanical Engineering from the University of California at Los Angeles (UCLA) in 2006, specializing in MEMS/Nanotechnology and minoring in Fluid Mechanics and Biomedical Engineering. He also has two-year (1996, 2000) work experience at Korea Aerospace Research Institute and three-year (1997-1999) teaching experience at Chandrakasem Rajabhat University in Thailand. He has now been working as an Assistant Professor in the Department of Mechanical Engineering at the Stevens Institute of Technology since 2007. His current research activities include large-area nanopatterning and 3D nanofabrication, microfluidic self-assembly of nanomaterials, fluid physics and heat transfer at nanoscale interfaces, nanofluidic energy harvesting, and cell-material interactions, funded by various federal agencies in US (NSF, DARPA, ONR, ARMY, and DOE) and industries. He has recently been named as a recipient of the 2010 Young Investigator Program (YIP) award by the US Office of Naval Research (ONR) for his efforts in the development of 3D nanostructures for energy-efficient anti-corrosive surfaces for naval applications and highlighted in Nature (http://www.nature.com/naturejobs/2010/100520/pdf/nj7296-385a.pdf).
Li Shi, Professor - Myron L. Begeman Fellow in Engineering, Department of Mechanical Engineering and Materials Science, University of Texas at Austin
"Thermal Transport in Graphene and Other Two-Dimensional Layered Materials"
Abstract: Graphene and other two-dimensional (2D) layered materials are being employed for fabricating electronic, energy, and other functional devices. The performance of many of these devices is dictated by thermal transport properties of the 2D building blocks. It has been suggested that the basal-plane thermal conductivity of suspended few-layer graphene and hexagonal boron nitride (h-BN) increases with decreasing thickness, and can exceed the already record-high values of graphite and bulk h-BN. However, these 2D materials are usually supported on a substrate or embedded in a medium for device applications. Hence, the effects of interface interaction on thermal transport in and across 2D building blocks must be understood. Here, we show that the basal-plane thermal conductivity decreases with decreasing thickness of few-layer graphene and h-BN in contact with an amorphous material, as well as bismuth telluride nanoplates with surface oxide. In addition, because internal interface thermal resistance is minimized in ultrathin-graphite foams, the thermal conductivity of the covalently bonded three-dimensional architecture greatly exceeds those of van der Waals-bonded carbon nanostructure networks that have been developed for thermal management.
Biography: Li Shi is a Professor of Mechanical Engineering and Materials Science and Engineering in University of Texas at Austin (UT Austin). He spent close to a decade in combustion research, which resulted in a bachelor degree in Thermal Engineering from Tsinghua University at Beijing in 1991, a master degree in Mechanical Engineering from Arizona State University in 1997, and four-year industrial research experience in between. His invention of micro-devices for studying thermal physics in individual carbon nanotubes earned him a doctoral degree in Mechanical Engineering from University of California at Berkeley in 2001. Dr. Shi investigated thermoelectric cooling as an IBM Research Staff Member for a year before moving to UT Austin in 2002 to build a program at the interface between thermal sciences and materials sciences. He currently serves as the Editor-in-Chief of Nanoscale and Microscale Thermophysical Engineering. His research accomplishments and professional services have been recognized by the CAREER Award from the National Science Foundation in 2003, the Young Investigator Award from the Office of Naval Research in 2004, the ASME Journal of Heat Transfer Outstanding Reviewer Award in 2005, the Myron L. Begeman Fellowship in Engineering at UT Austin in 2007, and the O’Donnell Award in Engineering from the Academy of Medicine, Engineering, and Science of Texas in 2013.
Wednesday, February 13 - Doctoral Defense
Towne Room 227, 11:00am
Xiaoning Shen, Ph.D. Candidate, University of Pennsylvania
Faculty Advisor: Paulo Arratia
"Locomotion of live organisms in complex fluids at low Reynolds number"
Abstract: Complex fluids are a broad class of materials that are usually homogeneous at the bulk and microscopic scales but possess internal structures at an intermediate scale. Such fluids are ubiquitous in nature and industry, and examples include colloidal suspensions, polymeric gels and solutions, human mucus, and blood. Many live organisms such as spermatozoa and bacteria live in complex fluids but our understanding of the main mechanisms that govern their motility in such fluids is still in its infancy. In this thesis, I present an investigation on the motility behavior of a biological model in both Newtonian and complex fluids. The organism is the nematode Caenorhabditis (C.) elegans that is widely used in biomedical and genetic research. I will focus on two main topics: (i) swimming in viscoelastic liquids and (ii) undulatory motility on wet surfaces. In the study of the effect of viscoelasticity on swimming, particle velocimetry and in-house developed nematode tracking software is used to characterize the flow fields and motility behaviors of C. elegans. I find that (a) the flow fields in Newtonian fluids exhibit an exponential decay trend that agrees well with theoretical results assuming low-Reynolds-number flow and hydrodynamic interactions; (b) compared to Newtonian solutions, fluid elasticity leads to up to 35% slower propulsion speed. In the study of the locomotion of C. elegans on wet surfaces, the kinematics of C. elegans moving on wet agar surfaces are characterized and a model based on lubrication theory is developed to understand such kinematic behaviors. Results show that the spatial patterns and bending force generated during the locomotion of C. elegans correlate well with previously described gait-specific features of calcium signals in muscle. I also find that one may be able to control the motility gaits of C. elegans by adjusting the magnitude of the surface drag coefficients.
The final chapter of this thesis is dedicated to applying the acquired knowledge on the motility kinematics (i.e. frequency, swimming speed, curvature, etc) and dynamics (i.e. force and power) for genetic and phenotypic analysis of C. elegans. In order to do so, I integrate image analysis algorithms and fluid as well as solid mechanics principles to describe wild-type and mutant C. elegans motility gaits. Quantification of body shapes and external hydrodynamics, and newly developed model-based estimates of biomechanics reveal that mutants affecting similar biological processes exhibit related patterns of biomechanical differences. The biomechanical profiling using C. elegans locomotion could be useful for predicting the function of previously unstudied motility genes.
Thursday, February 14 - Doctoral Defense
Towne Room 108, 10:30am
Lichao Pan, Ph.D. Candidate, University of Pennsylvania
Faculty Advisor: Paulo Arratia
"Complex Fluids In Microchanne Flows at Low Reynods Number: Elastic Instabilities and Rheology"
Abstract: Complex fluids, especially fluids containing polymer molecules, are frequently encountered
in everyday life from foods, paints, to cosmetics. Polymeric fluids are usually viscoelastic and do not flow like water. As a result, these fluids can exhibit flow instabilities even at low Reynolds number (Re) where viscous forces dominate inertial forces, and a new type of turbulence - the so-called purely elastic turbulence. It has been demonstrated that these nonlinear behaviors are arised from extra elastic
stresses due to the presence of polymer molecules in the fluid and the interaction of polymer molecules with the flow. Such flow instabilities of viscoelastic fluids have been experimentally observed in flows with curved streamlines. It is presently believed that parallel shear flow of viscoelastic fluids, like flow in a straight pipe or channel, are linearly stable.
The first part of this work investigates flow instabilities of viscoelastic fluids in microchannel system. Experiments are performed in a long, straight microchannel where the flow is perturbed by placing a variable number of cylinders (0 < n < 15). Downstream from the perturbation (i.e. cylinders), results show that the initial disturbance is sustained, in the form of temporal velocity fluctuations, far downstream from the obstacles (200 X channel width) in the parallel shear geometry above certain flow rate or Wissenberg number (Wi). These temporal fluctuations in velocity increase nonlinearly with Wi. Above a critical Wi (Wi > 5.4) and a critical number of obstacles (n >2), a sharply increase of velocity fluctuations together with a hysteresis loop indicate the presence of a subcritical elastic instability. It is also observed that, in the upstream regime, the initial disturbances can be spreaded far upstream and increase linearly with Wi suggesting the existence of a linear upstream instability.
Reliable rheological measurements of complex fluids are critical to the understanding
of the many anomalous flow phenomena involving complex fluids in particular those
containing polymers that lead to elastic instabilities. The second part of this thesis
is concerned with the rheological characterization of complex fluids in high-shear rate
environments. Such environments are found in lubrication and coating processes
as well as in flow through porous media. Microfluidics technology is used because,
due to its small length scale, the flow remains in the low Reynolds number regime
(Re <<1) while attaining high shear-rates (up to 10^4 1/s). Measurements of viscosity
of complex fluids including polymeric solutions and human blood plasma at high shear
rates are performed using microfluidic-based rheometry. Viscosity is estimated by
measuring the pressure drop along a microchannel using in-situ pressure sensors. The
micro pressure sensors are fabricated using conductive particles/PDMS composites in laboratory without sophisticated cleanroom facilities. Finally, a novel method is proposed and implemented to measure relaxation times of viscoelastic fluids at low strain in a microfluidic device.
Thursday, February 21
1:30 p.m., Towne 337
J. Scott Bunch, Assistant Professor, Department of Mechanical Engineering, University of Colorado at Boulder
"Graphene Mechanical Wonders"
Bio: Scott Bunch is currently an Assistant Professor of Mechanical Engineering at the University of Colorado at Boulder. He is primarily interested in the mechanical properties of atomically thin materials such as graphene. He received his B.S. degree in Physics from Florida International University (2000) and a Ph.D. in Physics (2008) from Cornell University where he studied the electrical and mechanical properties of graphene. After finishing his Ph.D, he spent 3 months as a postdoctoral researcher in the Laboratory of Atomic and Solid State Physics at Cornell University studying nanoelectromechanical systems before joining the faculty at CU Boulder in 2008. His awards include a Ph.D. fellowship from Lucent Technologies, Bell Laboratories (2000-2004), the DARPA MTO Young Faculty Award (2008), and the NSF CAREER Award (2011).
Friday, February 22 - The George H. Heilmeier Faculty Award for Excellence in Research
11:00 a.m., Wu & Chen Auditorium, Levine Hall
Vijay Kumar, UPS Foundation Professor, Mechanical Engineering and Applied Mechanics, University of Pennsylvania
"Aerial Robot Swarms"
Abstract: Autonomous micro aerial robots can operate in three-dimensional environments and
offer many opportunities for environmental monitoring, search and rescue, and first
response. In this lecture, Dr. Kumar will describe his recent work with small, agile aerial
robots, and discuss the challenges in the deployment of large numbers of aerial robots, with applications to cooperative manipulation and transport, construction, and exploration and mapping.
Monday, February 25
4:00-5:30 p.m., Room 307, Levine Hall
Roland Bennewitz, Senior Group Leader, Nanotribology Group, INM – Leibniz-Institute for New Materials and
Experimental Physics, Saarland University, Saarbrücken, Germany
"Nanoscale friction on gold – from the basics to electrochemical modification"
Abstract: In a classical description following concepts of Bowden and Tabor, two contributions determine friction on clean metal surfaces: shearing and ploughing. I will discuss results of single-asperity experiments performed on Au(111) in ultrahigh vacuum, which indicate a close relation between shearing and ploughing at the nanometer scale.
In a second part, I will present results from attempts to vary friction by electrochemical modification of gold surfaces. While in aqueous electrolytes a chemical reaction at the surface is required for a change of friction, in ionic liquids a potential-induced layering at the surface is sufficient to vary friction.
Bio: Roland Bennewitz studied physics in Freiburg and Berlin. He obtained his PhD from the Freie Universität Berlin with work on defects on insulating surfaces. Since his postdoctoral studies at the University of Basel, Switzerland, he is interested in high-resolution force microscopy and its application to nanotribology. He was a professor of physics at McGill University in Montreal, Canada, as Canada Research Chair in Experimental Nanomechanics and now leads the nanotribology group at the INM – Leibniz-Institute for New Materials in Saarbrücken, Germany.
Harry Swinney, Sid W. Richardson Foundation Regents Chairman and Professor of Physics, University of Texas at Austin
"How competing bacterial colonies can survive by killing siblings"
 Chen et al., Phys. Rev. Lett. 108, 148101 (2012)
 Be’er et al., PNAS 107, 6258 (2010)
 Be’er et al., mBio 2, 3 (2011)
Maria Yang, Robert N. Noyce Career Development Assistant Professor of Mechanical Engineering and Engineering Systems, Massachusetts Institute of Technology
"Influence of informal representation in early stage design "
Abstract: Engineering and product design are concerned with the creation of physical artifacts, from consumer products to complex, large scale engineering systems. My work considers the processes used in the early stages of design to bring these products and systems into being. The early stage of design has been shown to be highly impactful on design outcome, yet is ambiguous and rapidly evolving, and is therefore difficult to assess and predict. My research seeks to deepen our understanding of how designers synthesize designs and make decisions during the early stages of the design process. This talk will describe experimental work in understanding the role of information design representations, such as sketches, prototypes, and verbal discussion, in driving this early stage of design. How are quantity, quality, style and timing of representation linked to design outcome? This approach provides a novel means to assess both design process and the behavior of the designer in innovative ways. The talk will further touch on work in evaluating how human team behavior may affect how a design is optimized. The talk will conclude with future work in early stage design, along with thoughts on design curriculum.
Biography: Maria C. Yang is the Robert N. Noyce Career Development Assistant Professor of Mechanical Engineering and Engineering Systems (dual) at the Massachusetts Institute of Technology. Professor Yang earned her BS in Mechanical Engineering from MIT, and her MS and PhD from Stanford's in Mechanical Engineering. She is the recipient of an NSF CAREER Award and the MIT Earll Murman Excellence in Undergraduate Advising Award. Prior to MIT, she was an Assistant Professor of Industrial and Systems Engineering at the University of Southern California, and an instructor of design in mechanical engineering of the California Institute of Technology. She has been a lecturer in design at Stanford. Professor Yang’s industrial experience includes serving as Director of Design at Reactivity, Inc., a Silicon Valley company now a part of Cisco Systems. She has done research into user interface design at Apple Computer, Lockheed, and Immersion Corporation. Professor Yang's research and teaching interests are in the design of products and systems.
Thursday, March 21
Towne 337, 1:45 pm
Hugh Fan, Associate Professor, Department of Mechanical and Aerospace Engineering, Department of Biomedical Engineering and Department of Chemistry, University of Florida
"Microscale Components for Flow Control and Particle Isolation "
Abstract: Microfluidics is a field that promises to reach the holy grail of "lab-on-a-chip". In analogy to shrinking a computer from the size of a room in the 1950s to a laptop today, instruments for chemical and biological analyses may be miniaturized into microfluidic devices using modern microfabrication technology. Potential applications of the portable, miniaturized devices may include point-of-care testing (e.g., in emergency rooms), environmental monitoring, and detection of biowarfare agents in the field. In this presentation, brief review will be given on the concept of microfluidics, device fabrication, and fluid manipulation in microscale. The focus of the presentation will be on three enabling components: (1) microvalves for regulating flows, containing fluids, and isolating one region from the other in a device; (2) mixers for homogenization of reagents in biological reactions; and (3) sorter (or de-mixer) for separating and concentrating cancer cells from bodily fluids.
Biography: Dr. Z. Hugh Fan is an associate professor in the Department of Mechanical and Aerospace Engineering, Department of Biomedical Engineering, and Department of Chemistry at the University of Florida. Prior to joining UF in 2003, Dr. Fan was a Principal Scientist at ACLARA BioSciences Inc. (Mountain View, CA) from 2000 to 2003 and a Member of the Technical Staff at Sarnoff Corp. (Princeton, NJ) from1995 to 2000. He worked as a postdoctoral fellow at the Ames Laboratory of the US Department of Energy at Iowa State University in 1994. Dr. Fan received his B.Sc. from Yangzhou Teachers' College in China and his Ph.D. from the University of Alberta in Canada. His research interests include microfluidics, BioMEMS (Biomedical MicroElectroMechanical Systems), sensors, cancer diagnostics, and bioengineering. Dr. Fan's research has been funded by National Institute of Health (NIH), National Science Foundation (NSF), Army Research Office, National Aeronautics and Space Administration (NASA), and other agencies. He has authored over 50 journal articles that have been cited more than 3700 times. Dr. Fan is the recipient of Career Award from NIH in 2011, Fraunhofer-Bessel Award from Alexander von Humboldt Foundation (Germany) in 2010 and E. T. S. Walton Award from Science Foundation Ireland in 2009.
Friday, March 22 - Joint MEAM/GRASP/PRECISE
Berger Auditorium, 12:00 pm
Gary Fedder, Director of the Institute for Complex Engineered Systems (ICES), Howard M. Wilkoff Professor of Electrical and Computer Engineering, and Professor of The Robotics Institute, Carnegie Mellon University
"Advanced Manufacturing Institutes – A $2B National Experiment in Government-Industry-University Private-Public Partnerships"
Abstract: While the United States is a leading manufacturer in the world, our nation has been losing manufacturing jobs to overseas operations for the last three decades. This trend accelerated after 2000. Revitalizing our manufacturing sector is important for three compelling reasons: manufacturing provides high paying jobs that spawn service-sector jobs, product innovation is facilitated by co-location of design and production processes, and domestic manufacturing capability is vital to national security*. To address these concerns, in March 2012, President Obama announced a national initiative to create up to 15 institutes for advanced manufacturing as part of the National Network for Manufacturing Innovation (NNMI). Through a swift competition and selection process, a pilot institute for NNMI, called the National Additive Manufacturing Innovation Institute, was awarded in August 2012 with the winning team centered in the Ohio, Pennsylvania and West Virginia region. Competitions for three more NNMI institutes are forecast for this year. The NAMII and the NNMI institutes are instances of unique government-industry-university private-public partnerships that amount to an interesting national experiment to address the gap in R&D activities between applied research and productization. I will walk through the events leading to these national manufacturing initiatives, draw on some lessons already learned, and point to future opportunities for advanced manufacturing R&D. I will also describe a unique program, called Research for Advanced Manufacturing in Pennsylvania (RAMP) and led by Carnegie Mellon and Lehigh University, which seeds university R&D projects that are driven by industry needs.
* Report the President on Ensuring American Leadership in Advanced Manufacturing, President’s Council of Advisors on Science and Technology.
Biography: Gary K. Fedder is the Director of the Institute for Complex Engineered Systems (ICES), the Howard M. Wilkoff Professor of Electrical and Computer Engineering, and Professor of The Robotics Institute at Carnegie Mellon University. He also holds courtesy appointments in the Departments of Mechanical Engineering and Biomedical Engineering at Carnegie Mellon.
Dr. Fedder earned his B.S. and M.S. degrees in EECS from MIT in 1982 and 1984, respectively, and obtained the Ph.D. degree from the University of California at Berkeley in 1994. His personal research interests include microelectromechanical systems (MEMS) modeling and fabrication, integration of MEMS and CMOS, physical sensor design, nonlinear dynamics of MEMS, RF MEMS, gas chemical microsensors and implantable biosensors. He is an IEEE Fellow and has contributed to over 200 research publications and holds several patents in the MEMS area.
As Director of ICES, Professor Fedder leads the institute’s mission to act as a catalyst to identify, seed and grow new areas of multidisciplinary research in complex engineered materials, devices, processes and systems. Professor Fedder is co-director in collaboration with Lehigh University on two R&D programs funded through the Commonwealth of Pennsylvania’s Department of Community and Economic Development. The RAMP (Research on Advanced Manufacturing in Pennsylvania) program provides incentive to academic researchers to collaborate with PA industry partners in translational R&D in advanced manufacturing. The PITA (Pennsylvania Infrastructure Technology Alliance) program provides funding for early-stage R&D for products and processes of interest to PA companies.
From 2011 to 2012, Professor Fedder served as a technical co-lead in the policy subcommittee of the U.S. Advanced Manufacturing Partnership setup by President Obama. He worked with colleagues from industry and academia to generate recommendations that motivated the spring 2012 announcement of the National Network for Manufacturing Innovation (NNMI). Professor Fedder helped lead a team from the Pennsylvania, Ohio and West Virginia “Tech Belt” region to win the pilot institute for the NNMI called the National Additive Manufacturing Innovation Institute (NAMII).
Chang-Jin Kim, Professor, Micro- and Nano-Manufacturing Lab; California NanoSystems Institute Mechanical and Aerospace Engineering, UCLA
"Surface Tension Is Fair Game in Micro-Engineering: Let’s Play"
Abstract: Unlike in regular scale, where containers and pipes are needed to manipulate liquids, in sub-millimeter scale liquids can be handled as discrete objects using the liquid-air interface as virtual walls. This unusual option is a consequence of surface tension dominating other mechanical forces in microscale. Presented will be a series of engineering applications where the main design concepts are based on such unique microscale effects. The application examples include satellite-free inkjet printing; micro RF switches using liquid-metal droplets; and active micro fuel cells with no mechanical components. Furthermore, droplets can be actively and individually manipulated by voltages using the electrowetting-on-dielectric (EWOD) mechanism, which ushered the new field of digital microfluidics. Demonstrated to manipulate mostly aqueous droplets in air, EWOD-based microfluidics has accomplished many manipulative functions (e.g., creating and moving droplets, mixing and separating droplets, separating particles in a droplet) and developed several applications (e.g., sample preparation for MALDI-MS, radiosynthesis of tracers for PET scan). To demonstrate how EWOD microfluidics simplifies eventual lab-on-a-chip product, we showcase stand-alone handheld systems. Although based on microscale physics, the surface-tension engineering can be applied to large-scale systems as well. Finding the solutions in microscale details, we have developed superhydrophobic (SHPo) surfaces that can stay SHPo indefinitely even 70 meters deep underwater and reduce the drag of water flows significantly. Most recently we have obtained a drag reduction over 75% in turbulent-boundary-layer flows, which represent water vehicles.
Biography: Professor CJ Kim received his B.S. from Seoul National University, M.S. from Iowa State University, and Ph.D. from the University of California at Berkeley, all in mechanical engineering. He joined the faculty at UCLA in 1993. Directing the Micro and Nano Manufacturing Laboratory, his research is in MEMS and Nanotechnology, including design and fabrication of micro/nano structures, actuators and systems, with a focus on the use of surface tension. The recipient of the TRW Outstanding Young Teacher Award, NSF CAREER Award, ALA Achievement Award, and Samueli Outstanding Teacher Award, Prof. Kim has served on numerous professional and governmental committees and panels in MEMS and nanotechnology. An ASME Fellow, he is serving on the Editorial Board for the IEEE/ASME Journal of MEMS, the Editorial Advisory Board for IEEJ Transactions on Electrical and Electronic Engineering, as General Co-Chair of IEEE NEMS 2013 and General Chair of IEEE MEMS 2014. He has also been active in the commercial sector, as a board member, scientific advisor, consultant, and founder of start-ups.
Nicholas Ouellette, Assistant Professor of Mechanical Engineering and Materials Science, Yale University
"Emergent Dynamics of Laboratory Insect Swarms"
Abstract: Self-organized collective animal behavior--in swarms, flocks, schools, herds, or crowds--is ubiquitous throughout the animal kingdom. In part because it is so generic, it has engaged and fascinated scientists from many disciplines, from biology to applied mathematics to engineering. But despite this broad interest, little empirical data exists for real animals; modelers have therefore been forced to settle for only qualitative large-scale information or to make ad hoc assumptions about the low-level inter-individual interactions. In order to address this dearth of data, we have conducted a laboratory study of swarms of the non-biting midge Chironomus riparius. Using multicamera stereoimaging and three-dimensional particle tracking, we measure the trajectories and kinematics of each individual insect in the swarm, and study their statistics and interactions. I will present our measurements of both the large-scale emergent dynamics of the swarms and the interactions between individual insects, and discuss the implications of our measurements for modeling.
Biography: Nick Ouellette is currently as assistant professor in the Department of Mechanical Engineering & Materials Science at Yale University. He graduated from Swarthmore College in 2002 with a double major in Physics and Computer Science, and earned his Ph.D. (in Physics) in 2006 from Cornell University. Before coming to Yale, he was a postdoc at the Max Planck Institute for Dynamics and Self-Organization in 2006 and from 2007-2008 in the Physics Department at Haverford College. His research interests lie in self-organization in complex systems, and span fluid mechanics, collective motion in biology, and granular materials.
John Sader, Professor, Department of Mathematics and Statistics, University of Melbourne
"Nanomechanical Systems in Fluid with Applications to Atomic and Molecular Sensing"
Abstract: Invention of the atomic force microscope has driven numerous advances in the use and application of nanomechanical sensors. These include the imaging of surfaces with atomic and molecular resolution, measurement of inertial mass at the atomic scale and monitoring of biological processes in liquid. In this talk, I will give an overview of work performed in our group aimed at developing the capacity of dynamic atomic force microscope measurements, particularly for operation in fluid environments. I will also explore related technologies that make use of cantilever-based mass sensors, and nanoparticle systems that resonate in fluid environments at microwave frequencies.
Biography: John E Sader is a Professor in the Department of Mathematics and Statistics, University of Melbourne, Australia. He leads an interdisciplinary theoretical group studying a range of topics including the dynamic response of nanoparticles under femtosecond laser excitation, mechanics of nanoelectromechanical devices, high Reynolds number flow of thin films and rarefied gas dynamics in nanoscale systems. http://www.ampc.ms.unimelb.edu.au/srg
Thursday, April 11 - Doctoral Defense
Towne Room 227, 12:00 p.m.
William McMahan, Ph.D. Candidate, University of Pennsylvania
Faculty Advisor: Katherine Kuchenbecker
"Providing Haptic Perception to Telerobotic Systems via Tactile Acceleration Signals"
Touching a real physical object with a hand-held tool causes the tool to
experience high-frequency (tactile) accelerations that reflect the mechanical
characteristics of the contact. These haptic signals provide salient cues about
changes in tool-surface contact state and enable effortless identification of
material and surface properties. While humans make extensive use of these cues,
robots almost universally cannot sense them, and they are seldom provided to
the operators of telerobotic systems. Fortunately, the recent availability of
low-cost high-bandwidth accelerometers makes it practical to give telerobotic
systems with the capability of sensing and using these cues.
This dissertation presents a suite of methods we have developed for enabling
operators of telerobotic systems to use tactile accelerations to be more aware
of their physical interactions with the remote environment. The focus is on the
modeling, design and control of a haptic system capable of accurately recreating
tactile acceleration signals experienced by a teleoperated robot in real time.
This system has been implemented on multiple robotic systems, including the
Intuitive Surgical da Vinci Surgical System, an FDA-approved telerobotic system
that natively provides no haptic feedback. Building on prior work, we use
MEMS-based accelerometers to provide real-time measurement of the high frequency accelerations experienced by the robot as a result of environmental contact. We use a dedicated linear voice coil actuator to generate high fidelity recreations of the tactile acceleration signals for the user to feel at the operator interface. This approach involves signal processing methods to enhance the measured accelerations and dynamic modeling to carefully control the acceleration output of the voice coil actuator. The provided feedback feels natural and promises to reduce the operator's cognitive load and increase their situational awareness. A number of experiments confirm the feasibility and performance qualities of these systems. Additionally, we have preliminary evidence that tactile acceleration measurements can be a useful objective measure of the operator's technical skill in telerobotic surgery.
Thursday, April 11
2:00 p.m., Wu and Chen Auditorium, Levine Hall
Horacio Espinosa, James N. and Nancy J. Farley Professor in Manufacturing & Entrepreneurship
Director; Theoretical and Applied Mechanics Program, Northwestern University
"Atomistic Investigation of Nanomaterials - Seeing the Invisible and Bridging Theory and Experiments"
In the past decade, there has been a major thrust to develop novel nanomaterials exhibiting unique mechanical and electro-mechanical (e.g., piezoelectric) properties. These nanomaterials are envisioned as building blocks for the next generation of lightweight materials, electronic and energy harvesting systems. In this context, identification of size dependent mechanical and electrical properties is essential. However, such endeavor has proven challenging from both experimental and modeling perspectives. In this seminar, progress towards accurate identification of such properties will be reviewed. In particular, a MEMS platform for in-situ electron microscopy testing of one dimensional nanostructures will be introduced and used to identify mechanical property size effects in metallic (Ag) and semiconducting (ZnO, GaN) nanowires. Furthermore, the validity of force fields commonly used to model nanomaterials will be examined through one-to-one comparison to experimental findings and quantum mechanical simulations. In the case of semiconducting nanowires, it will be shown that force fields are accurate enough to capture elasticity but that higher order theories are needed to interpret nanowire failure and piezoelectric size effects. Opportunities arising from identified size effects in various applications of interest will be presented.
About the speaker: Horacio D. Espinosa is the James and Nancy Farley Professor of Manufacturing and Entrepreneurship in the McCormick School of Engineering and Applied Sciences at Northwestern University. He received his Ph.D. in Applied Mechanics from Brown University, in 1992. Professor Espinosa has made contributions in the areas of dynamic failure of advanced materials, micro, and nanomechanics.. Professor Espinosa is a foreign member of the European Academy of Arts and Sciences, the Russian Academy of Engineering, and Fellow of AAM, ASME, and SEM. He received numerous awards and honors including the Society for Experimental Mechanics LAZAN, HETENYI and SIA NEMAT-NASSER awards. He was the Timoshenko visiting Professor at Stanford University in 2011, President of the Society of Engineering Science in 2012, and was recently appointed to two committees of the National Academies, the Panel on Materials Science and Engineering to advise the Army Research Lab, and the U.S. National Committee on Theoretical and Applied Mechanics.
Lallit Anand, Warren and Towneley Rohsenow Professor of Mechanical Engineering, Massachusetts Institute of Technology
"A thermo-mechanically coupled theory for fluid permeation in elastomeric materials: application to thermally-responsive gels"
Abstract: An elastomeric gel is a cross-linked polymer network swollen with a solvent, and certain gels can undergo large reversible volume changes as they are cycled about a critical temperature. We have developed a continuum-level theory to describe the coupled mechanical deformation, fluid permeation, and heat transfer of such thermally-responsive gels. In discussing special constitutive equations we limit our attention to isotropic materials, and consider a model based on a Flory-Huggins model for the free energy change due to mixing of the fluid with the polymer network, coupled with a non-Gaussian statistical-mechanical model for the change in configurational entropy --- a model which accounts for the limited extensibility of polymer chains. We have numerically implemented our theory in a finite element program. We show that our theory is capable of simulating swelling, squeezing of fluid by applied mechanical forces, and thermally-responsive swelling/deswelling of such materials.
Biography: Lallit Anand, an alumnus of IIT, Kharagpur, earned his Ph.D. degree in 1975 from Brown University. The same year he joined the Mechanical Sciences Division of the Fundamental Research Laboratory of the U.S. Steel Corporation, and served successively as Research Scientist and Senior Research Scientist till 1981. In 1982 he joined the faculty of the Massachusetts Institute of Technology (MIT) as an Assistant Professor, and currently serves as the Warren and Towneley Rohsenow Professor of Mechanical Engineering.
At MIT he has served as the Head of the Area for Mechanics (2008-2013). During the five-year period 1994--1999, he served on the Executive Committee of the Applied Mechanics Division of ASME.
Anand teaches subjects related to Mechanical Behavior of Materials, Continuum Mechanics, and Plasticity at MIT. He has published over 100 archival journal papers, and advised the research of 25 Ph.D. students at MIT. He has recently co-authored a book titled The Mechanics and Thermodynamics of Continua with Morton Gurtin and Eliot Fried.
The honors he has received include:
• Esther and Harold E. Edgerton Assistant/Associate Professor of Mechanical Engineering, 1983-85.
• Eric Reissner Medal, 1992. For outstanding contributions to the field of Mechanics of Materials in the past decade. From the International Society for Computational Engineering & Sciences.
• Fellow of Singapore-MIT Alliance, 1999-2013.
• Fellow of American Society of Mechanical Engineers, 2003.
• Khan International Plasticity Medal, 2007. For outstanding life-long contributions to the field of Plasticity. From the International Journal of Plasticity.
• Warren and Towneley Rohsenow Professor of Mechanical Engineering, 2009- .
• Distinguished Alumnus Award from Indian Institute of Technology (IIT), Kharagpur, 2011.
Wednesday, April 17 - Doctoral Defense
Skirkanich Hall Room 243, 9:30 a.m.
Vahid Vahdat, Ph.D. Candidate, University of Pennsylvania
Advisor: Robert Carpick
"Mechanics of Interactions and Atomic-Scale Wear of Tips in Amplitude Modulation Atomic Force Microscopy Probes"
Thursday, April 18 - Joint MEAM/MRSEC Seminar
Meyerson Hall B1, 1:30 p.m.
Wilson Poon, Professor, School of Physics and Astronomy, University of Edinburgh
"Bacteria as active colloids"
Thursday, April 25, Heilmeier Hall - Towne 100, 1:30 p.m.
Emily Carter, Gerhard R. Andlinger Professor in Energy and the Environment, Professor of Mechanical and Aerospace Engineering & Applied and Computational Mathematics, Princeton University
"Quantum Mechanics and the Future of the Planet"
Abstract: To preserve the planet for future generations, we must make major science and engineering breakthroughs in the way we harvest, store, transmit, and use energy. I contribute to this effort by developing fast yet accurate quantum mechanics simulation methods used to investigate materials and phenomena related to sustainable energy. My current research includes: evaluating new materials for photovoltaics and photo-catalytic electrodes to convert sunlight into electricity and fuels, quantifying biofuel combustion kinetics, optimizing ion and electron transport in solid oxide fuel cells, evaluating mechanical properties of lightweight metal alloys for fuel-efficient vehicles, and investigating liquid lithium for fusion reactor walls. The latter two projects relate most closely to mechanical engineering and hence will be the focus of the talk. They exploit a promising quantum technique - orbital-free density functional theory (OFDFT) - that directly evaluates electron distributions. This method is orders of magnitude faster than standard DFT and as such it can be used to study many thousands of atoms with quantum mechanics. Consequently, OFDFT is able to explicitly study, e.g., structure and motion of dislocations and hence evaluate the origins of plasticity in metals from first principles. Recent advances in both theory and applications will be discussed.
Biography: Professor Carter is the Founding Director of the Andlinger Center for Energy and the
Environment at Princeton University and the Gerhard R. Andlinger Professor in Energy and the
Environment, as well as Professor of Mechanical and Aerospace Engineering and Applied and
Computational Mathematics. Her current research is focused entirely on enabling discovery and
design of molecules and materials for sustainable energy, including converting sunlight to electricity
and fuels, providing clean electricity from solid oxide fuel cells, clean and efficient combustion of
biofuels, optimizing lightweight metal alloys for fuel-efficient vehicles, and characterizing hydrogen
isotope incorporation into plasma facing components of fusion reactors. Professor Carter received
her B.S. in Chemistry from UC Berkeley in 1982 (graduating Phi Beta Kappa) and her Ph.D. in
Chemistry from Caltech in 1987. After a year as a postdoctoral researcher at the University of
Colorado, Boulder, she spent the next 16 years on the faculty of UCLA as a Professor of Chemistry
and later of Materials Science and Engineering. She moved to Princeton University in 2004. She
holds courtesy appointments in Chemistry, Chemical Engineering, and three interdisciplinary
institutes (PICSciE, PRISM, and PEI). The author of over 260 publications, she has delivered more
than 430 invited lectures all over the world and serves on numerous international advisory boards
spanning a wide range of disciplines. Her scholarly work has been recognized by a number of
national and international awards and honors from a variety of entities, including the American
Chemical Society (ACS), the American Vacuum Society, the American Physical Society, the
American Association for the Advancement of Science, and the International Academy of
Quantum Molecular Science. She received the 2007 ACS Award for Computers in Chemical and
Pharmaceutical Research, was elected in 2008 to both the American Academy of Arts and Sciences
and the National Academy of Sciences, in 2009 was elected to the International Academy of
Quantum Molecular Science, in 2011 was awarded the August Wilhelm von Hoffmann Lecture of
the German Chemical Society, and in 2012 received a Docteur Honoris Causa from the Ecole
Polytechnique Federale de Lausanne.