Author: Orlando E

Transport of Heat & Momemtum in Non-Equilibrium Wall-Bounded Flows

Posted on by

Friday, November 18 • 2:30 PM – PWEB, Rm. 175

Christopher White, Associate Professor of Mechanical Engineering

University of New Hampshire, Durham, NH 03824

Abstract: Non-equilibrium wall-bounded flows, in which perturbation time scales are comparable to turbulent flow time scales, do not exhibit universal behaviors and cannot be characterized only in terms of local parameters. Pressure gradients, fast transients and complex geometries are among the sources that can perturb a flow from an equilibrium state to a non-equilibrium state. Since all or some of these perturbation sources are present in many engineering application relevant flow systems and geophysical flows, understanding and predicting the non-equilibrium flow dynamics is essential to reliably analyze and control such flows. This talk will describe zongoing work using complementary numerical and physical experiments to better understand the underlying physics, transition dynamics, and appropriate flow scaling in non-equilibrium, periodic wall-bounded flows. The overarching goal is to use the results from these scientific investigations to improve upon the robustness of engine computational fluid dynamics (CFD) models so that they can be used for engineering design of low emission, high-efficiency piston engines.

Biographical Sketch: Dr. White received his Ph.D. in Mechanical Engineering from Yale University in 2001. From 2001-2004 he was Postdoctoral Research Fellow at Stanford University. Following his post-doctoral work, he joined Sandia National Laboratories as a Senior Member of the Technical Staff in the Combustion Research Facility. His principal duties at Sandia included lead investigator in the Advanced Hydrogen Fueled Engine Laboratory. In 2006, he joined the Mechanical Engineering Faculty at the University of New Hampshire.

Dr. White’s research is broadly motivated by applications related to the production, storage, distribution, conversion, and end-use applications of energy. His research to date is of both fundamental and applied nature in the areas of combustion, piston engines, biomass, ocean energy, and turbulent drag reduction. His 2006 paper “The hydrogen-fueled internal combustion engine: a technical review” is designed as a Highly Cited Paper (top 1% in the field of engineering) by the Thompson Reuters Essential Science Indicators. He co-authored an Annual Review of Fluid Mechanics paper in 2008 titled “Mechanics and prediction of turbulent drag reduction with polymer additives”. In 2009, he received an NSF CAREER award to study the flow properties and rheology of liquefied biomass suspensions. He currently has funding from NSF, DOE, and ONR.

For additional information, please contact Prof. Ying Li at (860) 486-7110, yingli@engr.uconn.edu or Laurie Hockla at (860) 486-2189, hockla@engr.uconn.edu

Seminar of Reconfigurable Plasmonics and Metamaterials

Posted on by

Friday, November 11 • 2:30 PM – PWEB, Rm. 175

Reconfigurable Plasmonics and Metamaterials

11-novYongming Liu, Assistant Professor

Department of Mechanical and Industrial Engineering

Department of Electrical and Computer Engineering

Northeastern University, Boston, USA

Email: y.liu@neu.edu;

Group Website: http://www.northeastern.edu/liulab

Abstract: Plasmonics has become a very important branch in nano optics. It allows us to concentrate, guide, and manipulate light at the deep subwavelength scale, promising enhanced light-matter interaction, next-generation optical circuits, sub-diffraction-limited imaging, and ultrasensitive biomedical detection [1-3]. Furthermore, the assembly of judiciously designed metallic structures can be used to construct metamaterials and metasurfaces with exotic properties and functionalities, including anomalous refraction/reflection, strong chirality and invisibility cloak [4,5]. There is a pressing need of tunability and reconfigurability for plasmonics and metamaterials, in order to perform distinctive functionalities and miniaturize the device footprint. In this talk, I will present our recent work in reconfigurable plasmonics and metamateirals. First, I will discuss the first demonstration of reconfigurable plasmonic lenses operating in microfluidic environment, which can dynamically diverge, collimate and focus surface plasmons [6]. Second, I will present a novel graphene metasurface to fully control the phase and amplitude of infrared light with very high efficiency. It manifests broad applications in beam steering, biochemical sensing and adaptive optics in the crucial infrared wavelength range [7]. Finally, I will discuss origami-based, dual-band chiral metasurfaces at microwave frequencies. The flexibility in folding the metasurface provides another degree of freedom for geometry control in the third dimension, which induces strong chirality from the initial, 2D achiral structure [8]. These results open up a new avenue towards lightweight reconfigurable metadevices.

Biographical Sketch: Dr. Yongmin Liu obtained his Ph.D. from the University of California, Berkeley in 2009. He joined the faculty of Northeastern University at Boston in fall 2012 with a joint appointment in the Department of Mechanical & Industrial Engineering and the Department of Electrical & Computer Engineering. Dr. Liu’s research interests include nano optics, nanoscale materials and engineering, plasmonics, metamaterials, biophotonics, and nano optomechanics. He has authored and co-authored over 50 journal papers, including Science, Nature, Nature Nanotechnology, Nature Communications, Physical Review Letters and Nano Letters. Dr. Liu received Office of Naval Research Young Investigator Award (2016), 3M Non-Tenured Faculty Award (2016), Air Force Summer Faculty Fellowship (2015), and Chinese Government Award for Outstanding Students Abroad (2009). Currently he serves as an editorial board member for Scientific Reports, EPJ Applied Metamaterials and Nano Convergence.

References: [1] S. A. Maier, “Plasmonics: fundamentals and applications”, Springer Science+ Business Media (2007); [2] T. Zentgraf et al., Nature Nanotechnology 6, 151 (2011); [3] Y. M. Liu, et al., Nano Letters 12, 4853 (2012); [4] Y. M. Liu and X. Zhang, Chemical Society Reviews 40, 2494 (2011); [5] K. Yao and Y. M. Liu, Nanotechnology Review 3, 177 (2014); [6] C. L. Zhao et al., Nature Communications 4:2350 (2013); [7] Z. B. Li et al., Scientific Reports 5, 12423 (2015); [8] Z. Wang et al., manuscript in preparation.

For additional information, please contact Prof. Ying Li at (860) 486-7110, yingli@engr.uconn.edu or

Laurie Hockla at (860) 486-2189, hockla@engr.uconn.edu

Probing Thermophysical Properties of Micro/Nanostructured Materials Using Ultrafast Pump

Posted on by

Friday, November 4 • 2:30 PM – PWEB, Rm. 175

Probing Thermophysical Properties of Micro/Nanostructured Materials Using Ultrafast Pump- Probe Technique

xiaojia-xj-wang

Xiaojia “XJ” Wang

Benjamin Mayhugh Assistant Professor of Mechanical Engineering University of Minnesota, Minneapolis, MN

Abstract: Micro/nanostructured materials behave differently from their macroscale counterparts with regards to thermal energy transport at short time and length scales. The engineering of micro/nanostructures to tailor thermal properties for energy conversion has become an emerging field in thermal science. One of the grand challenges in this area is to achieve sufficient spatial and temporal resolutions for accurate thermal measurements of these materials. This talk will emphasize how ultrafast pump-probe technique, Time-Domain Thermoreflectance (TDTR) and its upgraded version, Time-Resolved Magneto-Optical Kerr Effect (TR- MOKE), can be used to probe thxiaojia-xj-wang2ermal properties with microscale spatial resolution and sub-picosecond temporal resolution. Examples include: 1) TR-MOKE as a novel way to explore the origins of the anisotropic thermal transport in black phosphorus with enhanced measurement sensitivity; and 2) nanoparticle-assisted localized heating for probing interfacial thermal resistance at nanometer scales.

Biographical Sketch: Dr. Xiaojia Wang started her official appointment as an assistant professor in the Department of Mechanical Engineering at the University of Minnesota, Twin Cities in 2014. Prior to this, she was a postdoctoral research associate in the Department of Materials Science and Engineering at the University of Illinois at Urbana-Champaign. She received her Ph.D. in Mechanical Engineering from the Georgia Institute of Technology in 2011, and her M.S. in 2007 and B.S. in 2004 from Xi’an Jiaotong University, China, all in Mechanical Engineering. Her current research focuses on utilizing ultrafast optical techniques to characterize thermal transport in micro/nanostructured materials and across material interfaces, and tailoring the radiative properties of micro/nanostructures for energy conversion and harvesting. For details, please visit her research group website: http://www.me.umn.edu/labs/mnttl/

For additional information, please contact Prof. Michael T. Pettes at (860) 486-2855, michael.pettes@uconn.edu or Laurie Hockla at (860) 486-2189, hockla@engr.uconn.edu

Design for Discovery: Structural Shape & Topology Optimization

Posted on by

Friday, September 30 • 2:30 PM – PWEB, Rm. 175

Design for Discovery: Structural Shape & Topology Optimization with a Level Set Approach

Shikui Chen

Professor of Mechanical Engineering State University of New York at Stony Brook

Abstract: Topology optimization is an optimization-driven methodology which is capable of generating an optimal design without depending on the designers’ intuition, experience and inspiration. Topology optimization plays a crucial and rapidly expanding role in conceptual design and innovation, especially in automotive, aerospace and machine industries. In this talk, the speaker will make a brief review of the state of the art and introduce a level-set based topology optimization framework. In the level set framework, the boundary of the design is implicitly represented as the zero level set of a one-higher-dimensional level set function. Embedding the design in one higher dimension allows the flexibility in topological changes such as boundary merging or splitting in the design process, while keeping the boundary of the design clearly defined. After that, the speaker will report some of our recent effort to advance the level-set based topology optimization both in methodology and in applications. Selected topics include a variational distance- regularized parametric level set method, distributed compliant mechanisms synthesis, multi-physics energy harvester design, robust shape and topology optimization (RSTO) under uncertainty, and integrated design and additive manufacturing of heterogeneous mechanical metamaterials.

Biographical Sketch: Professor Shikui Chen is an Assistant Professor at the State University of New York, Stony Brook since 2013. He earned his Ph.D. in mechanical engineering from Northwestern University in 2010. Dr. Chen’s research interests are in the area of predictive science based design optimization, particularly in the fields of structural shape and topology optimization, geometric modeling with level set methods, multiphysics simulation, PDE-constrained optimization, and simulation-based design under uncertainty. His research work has been funded by government and industry grants including National Science Foundation (NSF), University Transportation Research Center (UTRC), Ford Motor Company, Stratasys and SUNY Materials and Advanced Manufacturing Network of Excellence. Dr. Chen is a member of ASME and AIAA. He was the recipient of the ASME Compliant Mechanisms Theory Award in the ASME 31st Mechanisms and Robotics Conference in 2007.

For additional information, please contact Prof. Ying Li at (860)486-7110, yingli@engr.uconn.edu or Laurie Hockla at (860)486-2189, hockla@engr.uconn.edu.

Electro-Chemo-Mechanics of Solids and Its Applications

Posted on by

Friday, October 7 • 2:30 PM – PWEB, Rm. 175

Electro-Chemo-Mechanics of Solids and Its Applications in Fuel Cells and Batteries

jianmin-qu

Jianmin Qu

Dean, School of Engineering Karol Family Professor Professor of Mechanical Engineering Tufts University, Medford MA 02155

Abstract: Materials used in energy conversion and storage devices are often subjected to multi-field driving forces (electrical, chemical, radiological, thermal, mechanical, etc.). In predicting the deformation and failure of these materials, conventional mechanics of material theories are no longer adequate, because these multi- field driving forces are typically coupled and produce synergetic effects that are not predicted by the classical theories. To fully understand how the different driving forces interact requires theories and models that are capable of accounting for the coupling of multi-field interaction processes.

In this talk, a theory for the mechanics of solids will be presented that accounts for the coupled effects of mechanical, electrical and chemical driving forces. The presentation will begin with an introduction of the general framework of the electro-chemo-mechanics, followed by examples of its applications to solid oxide fuel cells and Li-ion batteries. Finally, path-independent integrals in electro-chemo-mechanics will be discussed.

Biographical Sketch: Jianmin Qu is Karol Family Professor and Dean of School of Engineering at Tufts University, where he holds an appointment in the department of Mechanical Engineering. Dr. Qu received his Ph.D. and Master’s degrees from Northwestern University in theoretical and applied mechanics. Prior to joining Tufts, Dr. Qu was a Walter P. Murphy Professor in the McCormick School of Engineering and Applied Science at Northwestern University from 2009 to 2015. Before returning to his alma mater in 2009, Dr. Qu was on the faculty of the School of Mechanical Engineering at the Georgia Institute of Technology from 1989 to 2009.

Professor Qu’s research focuses on several areas of theoretical and applied mechanics including micromechanics of composites, interfacial fracture and adhesion, fatigue and creep damage in solder alloys, thermomechanical reliability of microelectronic packaging, defects and transport in solids with applications to solid oxide fuel cells and batteries, and ultrasonic nondestructive evaluation of advanced engineering materials. He has authored/co-authored two books, 12 book chapters and over 200 referred journal papers in these areas.

For additional information, please contact Prof. Ying Li at (860)486-7110, yingli@engr.uconn.edu or Laurie Hockla at (860)486-2189, hockla@engr.uconn.edu.

High-throughput 3D Printing of Functional Biomedical Devices

Posted on by

Friday, September 9 • 2:30 PM – PWEB, Rm. 175

High-throughput 3D Printing of Functional Biomedical Devices 

9-sep

 

Cheng Sun

Professor of Mechanical Engineering

Northwestern University, Evanston IL 60208

Abstract: Advancements in healthcare have opened up the promising opportunities for personalized medicine to improve patient outcomes while decreasing costs. However, widespread adoption remains a major challenge due to the additional time and expense required to individualize treatments to patient-specific conditions. Three-dimensional (3D) printing is an emerging technology with the potential to fabricate personalized biomedical devices at low cost with extremely short lead-time. Recent achievements in the field have utilized 3D printing to manufacture arterial stents, airway tubes, bones, and dental prosthetics with relative large dimensions. However, there remains a knowledge gap for the fabrication of biomedical device with fine feature size without compromising the fabrication speed. I will talk about a highly scalable 3D printing system – continuous liquid interface production microstereolithography (μCLIP) with sub-10 um fabrication precision. I will present our recent development of fast 3D printing of completely customizable stents using the μCLIP process. Stents achieved a lateral resolution of 7.1 x 7.1 mm, with a curing thickness of 20 mm. A 20 mm length stent was printed in approximately 70 minutes and had adequate strength. The mechanical properties of 3D-printed stents with struts of 150 µm and walls thickness of 500 μm were comparable to those of a control bare metal nitinol stent. Furthermore, 3D-printed stents are customizable, could be compressed and self-expanded within a clinically relevant time frame upon deployment, and significantly improve the mechanical properties of a pig artery after deployment. Furthermore, I will discuss the method to fabricate a customized contact lens using 3D printed mold. The biocompatibility and optical performance of the lens has been further characterized experimentally using rat model.

 

Biographical Sketch: Professor Cheng Sun is an Associate Professor at Mechanical Engineering Department at Northwestern University, where he has been since 2007. He received his PhD in Industrial Engineering from Pennsylvania State University in 2002. He received his MS and BS in Physics from Nanjing University in 1993 and 1996, respectively. Prior to coming to Northwestern, he was a Chief Operating Officer and Senior Scientist at the NSF Nanoscale Science and Engineering Center for Scalable and Integrated Nanomanufacturing at UC Berkeley. Dr. Sun received a CAREER Award from the National Science Foundation in 2009 and ASME Chao and Trigger Young Manufacturing Engineer Award, 2011. Dr. Sun’s primary research interests are in the fields of advanced manufacturing necessitate developments the emerging applications in the areas of photonics, energy, and biomedical engineering. His research group is engaged in developing novel micro-/nano-scale fabrication techniques and integrated nano-system. He has published more than 70 journal papers including publications in Science, Nature Nanotechnology, Nature Materials, and Nature Communication. http://sun.mech.northwestern.edu.

For additional information, please contact Prof. Ying Li at (860) 486-7110, yingli@engr.uconn.edu or Laurie Hockla at (860) 486-2189, hockla@engr.uconn.edu

From Realistic Human-Computer Interaction to Nanomachines: Prof. Horea Ilies has recently received 3 grants form the National Science Foundation totaling $1.35M

Posted on by

Three recent grants have been awarded by the National Science Foundation to Prof. Horea Ilies to support the current research in his Computational Design Laboratory.

The ability to measure how well objects “fit together” is a key task in engineering design and manufacturing as well as in the broad scientific arena whenever the behavior and function of a system is dependent on proper geometric alignment. For example, assembly planning from macro to nanoscale, layout optimization and packaging, design for human variability, synthesis and self-assembly of nano-machines, novel drug design, comparative shape analysis (shape similarity), as well as personalized medicine and medical devices are all applications in which the system’s behavior and function depends on the proper geometric alignment of individual components. One of the grants, based on the work with Dr. Morad Behandish, focuses on developing a generic framework for geometric interfaceability in virtual product development aimed at quantifying and interpreting how well objects of arbitrary geometric complexity fit together. 

A second grant is exploring the extension of the geometric interfaceability framework to develop effective haptic interaction mechanisms for intelligent human-computer or human-robot systems with a focus on virtual assembly tasks. The research uses haptic devices, which add the sense of touch when interacting with digital models and simulations, and are used in a variety of research, industrial and consumer applications, from engineering design, to computer-assisted surgery, and gaming.

The latest NSF-grant received by Prof. Ilies, in collaboration with Dean Kazem Kazerounian, focuses on the systematic design, analysis and control of manufacturable nanomachines such as the nanorobots built from protein molecules. In this research, Profs. Ilies and Kazerounian aim to develop a theoretical and computational framework to systematically design, and analyze self-assemblable molecular machines with prescribed mobility and function obtained from a predefined library of molecular primitives. The research aims to develop the tools required to perform design space explorations for synthetic and controllable molecular machines and devices, potentially leading to novel molecular motor functions that can be used to develop smart nanorobots and materials.

A paper authored by Morad Behandish and Prof. Horea Ilies places 2nd in the Best Paper Award Competition at the 2015 SIAM/ACM conference on Geometric and Physical Modeling.

Posted on by

A paper authored by Dr. Morad Behandish and Professor Horea Ilies placed 2nd in the 2015 SIAM/ACM conference on Geometric and Physical Modeling. The conference, with a historically low acceptance rate below 30%, brings together applied mathematicians, computer scientists and engineers from academia and industry to exchange new ideas in relevant mathematical theory, geometric and physical modeling, analysis, simulation and processing, as well as various applications. The title of the paper presented with this award is “Analytic Methods for Geometric Modeling via Spherical Decomposition,” and has been published in the special issue of Computer-Aided Design, vol. 70, pp. 100-115, January 2016.

Previously, the two UConn researchers won two consecutive Best Paper Awards at the 2014 and 2015 Computers and Information in Engineering (CIE), which is part of the annual international ASME IDETC & CIE Conferences.

Prof. Michael T. Pettes receives the NSF CAREER award

Posted on by

Prof. Michael T. Pettes is the recipient of a National Science Foundation CAREER award from the Chemical, Bioengineering, Environmental, and Transport Systems (CBET) NSF Directorate for his proposal “CAREER: Understanding the Roles of Strain and Mass Disorder on Fundamental Thermal Transport Processes in Two-Dimensional Materials.” Read more in the UConn Today article.