We are pleased to outline the five Technology/Science Update Talks that are being held this year at ITherm. Each can be attended in place of other parallel sessions. Read individual session descriptions below.
#1: Embedded Cooling of High Power Components (DARPA GEN-3)
Six talks by key technologists working on the DARPA initiative.
#2: Pool Boiling and Fluid Self-Propulsion
Two talks from key programs, with new findings.
#3: Mobile Thermal Management
Two talks on issues with high-performance passively cooled high-density packaging.
#4: Power Electronics: VHF Power Conversion, Automotive Drive Systems
Two talks on high-power DC transformation and motor propulsion.
#5: Nanoengineered and Porous Microstructures for Enhanced Thermal-Fluid Transport
Two talks on new directions in surfaces, wicking, phase-change and heat removal.
#6: Nanophononic Materials
Two talks on metameterials, energy harvesting, and thermal transport.
#7: Beyond Classical Scaling: Alternative Path towards Energy Efficient Systems
Two talks on 3D and other approaches to conserving energy.
#1: Embedded Cooling of High Power Components
Co-Chairs: Prof. Suresh Garimella, (Purdue), Dr. Kamal Sikka, (IBM), Prof. Avi Bar-Cohen (DARPA)
The rapid emergence of 2.5D and 3D packaging architectures and hot-spot driven thermal management requirements in high performance systems are overwhelming the cooling capacity of the current, Gen-2, thermal management technology. The inherent thermal limitations of Gen-2 technology, with its reliance on attached coldplates and heat sinks to remove dissipated heat, have spawned a new, “embedded cooling” paradigm which combines microfluidic cooling with high thermal conductivity substrates and thermal interconnects to extract the heat from the chips, substrates, and packages where heat is generated.
This Technology Update Session will introduce the ITHERM participants to the DARPA supported efforts underway in industry and academia to develop and demonstrate Gen-3 “embedded cooling” techniques capable of removing kW/cm2 chip heat fluxes and kW/cm3 chip stack heat densities, while suppressing the temperature rise of multi-kW/cm2 sub-mm hot spots. The invited speakers will provide phenomenological descriptions, governing equations, and an analysis of the state-of-the-art in diamond substrates, on-chip thermoelectric cooling, and single-phase as well as two-phase cooling in microgap channels for high-performance electronic modules. The specific topics and speakers include:
* Evaporative Microfluidic Cooling of HPC Module – T. Chainer, IBM
* Thermal Transport in Diamond Substrates – K. Goodson, Stanford
* Two-Phase Heat Transfer in Microchannels – Y. Peles, RPI
* Multi-scale Modeling of Evaporative Cooling Systems – J.A. Weibel, Purdue
* Thermoelectric Remediation of Hot Spots – B. Yang, UMD
* Digital Liquid Delivery for Hot Spot Cooling – S.M. You, UT-Dallas
#2: Pool Boiling and Fluid Self-Propulsion
Two Speakers: Prof. Satish Kandlikar (Rochester Institute of Technology), Prof. Vinod Narayanan (Oregon State University)
Revival of Pool Boiling For High Heat Flux Dissipation
Pool boiling heat transfer is employed extensively in many applications, including electronics cooling. Increasing critical heat flux was a major thrust until recently. However, with the need to provide more energy efficient solutions, there is an increased emphasis on simultaneously increasing the heat transfer coefficient as well. The talk highlights the exploratory path followed by various researchers in this area and presents new developments in the author’s laboratory where significant enhancements in critical heat flux were achieved at record low wall superheat values. These developments are of relevance in electronics cooling industry as two-phase cold plates and direct chip cooling are becoming attractive options in cooling high heat flux generating electronic devices. These results also guide us in developing even higher performing flow boiling systems.
Satish Kandlikar is the Gleason professor of Mechanical Engineering at Rochester Institute of Technology. He has been working in the area of pool and flow boiling, electronics cooling, microchannel flows, heat exchanger design and water management in fuel cells for over three decades.
Engineered Microstructures for Fluid Self-propulsion During Boiling and Condensation
Passive thermal management is of great interest in cooling of electronics and avionics in terrestrial and reduced gravity environments. In this talk, we present the use of meso-and micro-scale asymmetric surface patterns to generate preferential fluid motion during phase change. The asymmetric patterns take the form of 30-60 degree ratchets. This preferential motion is demonstrated for both boiling and condensation.
During pool boiling using these surfaces, the asymmetric geometry of microstructures causes bubbles to preferentially grow normal to the surface rather than in a vertical direction, resulting in a net liquid motion parallel to the heated surface. We explain the liquid motion using a semi-empirical force balance. We extend the concept of self-propulsion to an open ended channel configuration, wherein we present high-speed videos that document preferential motion of vapor slugs with velocities in the range of several mm/s.
During film condensation on horizontal ratcheted surfaces, we observe preferential rise of condensate towards the crest of the steeper slope, resulting in a cascade of the condensing film in a preferential direction. We discuss the causes for the preferential condensate motion and offer comparisons between computational fluid dynamics simulations and experimental results.
Vinod Narayanan is an Associate Professor and the James Welty Faculty Fellow in the School of Mechanical Industrial and Manufacturing engineering at Oregon State University (OSU). His areas of interest include infrared thermography methods, microscale flow and heat transfer applied to renewable energy, and thermal management. He is the Chair of ASME’s K-13 committee on Heat Transfer in Multiphase Systems, the co-chair of the International Conference on Nanochannels, Microchannels, and Minichannels (ICNMM) in 2014 and the chair of the 2015 ICNMM conference.
#3: Mobile Thermal Management
Chair: Victor Chiriac, Qualcomm
Speakers: Ponniah Ilavarasan, Manager of Power/Performance/Thermal Group, Intel Corporation; and Ashish Gupta, Manager of Thermal and Fluids Core Competency Group, Intel Corporation
Now more than ever, consumers are drawn towards mobile devices (tablets, phablets, and phones) which provide thinner form factors, richer and bigger displays and better multimedia capabilities. The functionality crammed into mobile devices will only continue to grow as consumers turn to their mobile devices to do more of their complex and rich functionality tasks. Thermal management and control of these passively cooled devices is of prime importance given the chassis design constraints and thermodynamic space limitations. At the same time, end users expect high levels of performance from their hand-held and mobile devices, and the trend from one generation to the next is increased performance while reducing thermodynamic space (thinner devices). The intersection of these two design philosophies meets at the end-user expectations: is the user willing to trade ergonomics (hotter devices) for increased performance, or is the end user willing to sacrifice performance for better ergonomics & battery life? These questions bring unique challenges for the thermo-mechanical community. This talk discusses most of these major challenges for current and next-generation mobile devices from an industry perspective and also various approaches that need to be taken to balance performance with ergonomics in a quantifiable manner.
Dr. Ponniah Ilavarasan currently manages the Power, Performance, and Thermal team in Intel’s Mobile Communication Group (MCG) in Portland, Oregon. He holds a Ph.D. degree in Electrical Engineering from Michigan State University. His group is responsible for delivering maximum performance in a thermally constrained environment such as Tablet, Phablet, and Smartphone. This includes delivering cost optimized system thermal solutions for maximum sustainable component and system thermal power envelope in a thin form factor devices, and collaborating with power/silicon architects to minimize power for high stress use cases. Ponniah also managed various disciplines such as EMI/ESD, wireless/antenna design, and signal integrity.
Dr. Ashish Gupta manages the Thermals and Fluids Core Competency Team in Intel’s Assembly and Test Technology Development (ATTD) Group in Chandler, Arizona. He holds a Ph.D. degree in Mechanical Engineering from Purdue University. His group is responsible for the R&D of advanced package thermal and cooling technologies, modeling methodologies and metrologies for Intel’s current and future generations of processors for product segments during the discovery, definition, development and certification stages of technology maturity. The team‘s scope cover the entire gambit of Intel product segments across all market segments ranging from hand held devices and small form factor packages in constrained physical/thermal environments to higher power server products.
#4: Power Electronics
Chair: Prof. Samuel Graham
Revolutionizing Power Electronics with Very High Frequency Power Conversion
Prof. Juan Rivas, Electrical Engineering, Stanford University
Power supplies are everywhere from consumer electronics, to medical imaging systems, to military systems. Modern applications demand power supplies that are smart and efficient, but traditional designs are inefficient, large, noisy, and expensive. A new generation of power electronics based on very high switching frequencies is providing energy savings, extremely small size, and reduced electrical noise. As an added benefit, such designs enable operation in automotive and similar harsh environments.
Professor Rivas came to Stanford as an assistant professor in January 2014. He was an assistant professor in Electrical Engineering at the University of Michigan. Before becoming a faculty member in 2011, he worked for the General Electric Global Research Center developing power electronics for medical imaging and aviation systems. He received the B.Sc. degree in electrical engineering from the Monterrey Institute of Technology (Mexico) in 1998. He obtained his masters (2003) and doctoral degree (2006) at the Massachusetts Institute of Technology. His research interests are in power electronics, RF power amplifiers, resonant converters, soft switching topologies and design of power converters for operation in harsh environments.
Thermal Management and Reliability of Automotive Electric Traction Drive Systems
Increasing the number of electric-drive vehicles (EDVs) on America’s roads has been identified as a strategy with near-term potential for dramatically decreasing the nation’s dependence on oil―by the U.S. Department of Energy (DOE), the federal cross-agency EV-Everywhere Challenge, and the automotive industry. Mass-market deployment will rely on meeting aggressive technical targets, including improved efficiency and reduced size, weight, and cost. Many of these advances will depend on optimization of thermal management.
Effective thermal management is critical to improving the performance and ensuring the reliability of EDVs. Efficient heat removal makes higher power densities and lower operating temperatures possible, and in turn enables cost and size reductions. The National Renewable Energy Laboratory (NREL), along with DOE and industry partners is working to develop cost-effective thermal management solutions to increase device and component power densities. In this presentation, the activities in recent years related to thermal management and reliability of automotive power electronics and electric machines will be presented.
Sreekant Narumanchi is the Section Supervisor and Team Lead of the Advanced Power Electronics and Electric Machines (APEEM) Team at the National Renewable Energy Laboratory. He leads a team of 12 engineers, postdocs and interns focused on thermal management and reliability of power electronics and electric machines. This includes investigation of various cooling technologies, thermal interface materials/interfaces, interconnects, as well as reliability of these components. Sreekant’s broad research interests include heat transfer, power electronics and motor thermal management, packaging and reliability.
Sreekant has published over 45 peer-reviewed papers (Conference Proceedings, Journal and Magazine Articles) and book chapters. He is also active professionally as a reviewer and on the editorial board for numerous journal and conferences in the area of heat transfer, thermal management and electronics packaging, as well as a reviewer for federal agencies such as the Department of Energy and the National Science Foundation. He received the Best Paper Award from the ASME Journal of Electronic Packaging (2003), the ASME InterPACK Conference Outstanding Paper Award (Second Place – 2013), the 2013 NREL Outstanding Business Collaboration Award, and the 2009 NREL Staff Award for Outstanding Performance. He received his Ph.D. from Carnegie Mellon University (2003), M.S. from Washington State University (1999), and B. Tech. from Indian Institute of Technology – Kanpur (1997), all in Mechanical Engineering.
#5: Nanoengineered and Porous Microstructures for Enhanced Thermal-Fluid Transport
Nanoengineered Surfaces for Enhanced Thermal-Fluid Transport Properties
Thermal-fluid-surface interactions are ubiquitous in multiple industries including Energy, Water, Transportation, Electronics Cooling, Buildings, etc. Over the years, these systems have been designed for increasingly higher efficiency using incremental engineering approaches that utilize system-level design trade-offs. These system-level approaches are, however, bound by the fundamental constraint of the nature of the thermal-fluid-surface interactions, where the largest inefficiencies occur. In this talk, we show how surface/interface morphology and chemistry can be engineered to fundamentally alter these interactions in a wide range of processes involving fluid, heat and mass transport processes including, condensation, boiling, drop/bubble dynamics, freezing, etc. We study the wetting energetics and wetting hysteresis of droplets in an Environmental SEM (ESEM) as a function of surface texture and surface energy and establish various wetting regimes and conditions for wetting transitions. We extend these concepts to dynamic wetting and establish optimal design space for droplet shedding, impact resistance, and contact time. We then present the behavior of surfaces under phase change, such as condensation, and freezing at both macroscale and microscale (using ESEM) and find their non-wetting properties can be compromised due to nucleation of water or frost within texture features. Based on these insights we introduce lubricant-impregnated surfaces that can promote dropwise condensation and reduce ice adhesion. We discuss unconventional contact line morphology, thermodynamics and dynamics of droplet shedding on these surfaces and show how even complex and low surface tension fluids can slide off the surface easily. Finally, we discuss the influence of electronic structure on interfacial wetting interactions and use these insights to develop new class of ceramic materials that are intrinsically hydrophobic. Applications of these nanoengineered surfaces for dramatic efficiency enhancements in various energy, water, and transportation systems including oil & gas, turbines, engines, power and desalination plants, and electronics cooling will be highlighted.
Kripa Varanasi is a Doherty Associate Professor in the Department of Mechanical Engineering at MIT. He received his B.Tech from IIT, Madras, India and his MS (ME and EECS) and Ph.D from MIT. Prior to joining MIT, Dr. Varanasi was a lead research scientist and project leader in the Energy & Propulsion and Nanotechnology programs at the GE Global Research Center, Niskayuna, NY, and was the PI for the DARPA Advanced Electronics Cooling program. The primary focus of his research is in the development of nano-engineered surface, interface, and coating technologies that can dramatically enhance performance in energy, water, agriculture, transportation, buildings, and electronics cooling systems. He is enabling this approach via highly interdisciplinary research focused on a nanoengineered surfaces and interfaces, thermal-fluid science and new materials discovery combined with scalable nanomanufacturing. His work spans various thermal-fluid and interfacial phenomena including phase transitions (condensation, boiling, freezing), nanoscale thermal transport, separation, wetting, catalysis, flow assurance in oil and gas, nanofabrication, and synthesis of inorganic bulk and nanoscale materials guided via computational materials design. Dr. Varanasi has filed more than 50 patents in this area. He was awarded the First Prize at the 2008 ASME Nanotechnology Symposium and won several awards at GE Research Labs including Technology Project of the Year, Best Patent Award, Inventor Award, and Leadership Award. He has received the MIT Energy Initiative award, 2010 IEEE-ASME ITherm best paper award, NSF Career Award and DARPA Young Faculty Award. He is commercializing some of the slippery coating technology under LiquiGlide for which his team received the audience choice award at the MIT 100K and First prize at MassChallenge Entrepreneurship competitions. Time Magazine and Forbes Magazine have named his invention LiquiGlide one of the Best Inventions of the Year. He was most recently awarded the 2013 Outstanding Young Manufacturing Engineer award by the Society of Manufacturing Engineers and Bergles-Rohsenow Heat Transfer Award by ASME.
Tailoring Porous Microstructures for High-Heat-Flux Vapor Chamber Applications
The need for concurrent size, weight, and performance improvements in high-performance electronics systems, without resort to active liquid-cooling strategies, demands passive heat-spreading technologies that can dissipate extremely high heat fluxes from small hot spots. In response to these daunting application-driven trends, our previous investigations have focused on the design, characterization, and fabrication of ultrathin vapor chambers for proximate heat spreading away from these hot spots. Noteworthy advances in fundamental understanding of the unique predominant transport mechanisms and operational limits found in this application, viz., phase change in porous microstructures fed by capillary action and the design of multiscale nanostructured wicks for enhanced transport, are briefly reviewed (AHT, 45, 4, 2013). Practical design and implementation of such devices is found to hinge upon accurate analysis and prediction of microstructure transport characteristics, a topic of extensive prior research owing to the stochastic nature and geometric complexity of the sintered materials commonly employed. Our recent investigations focus on approaches for direct simulation of transport in realistic geometric representations and reverse engineering of wick structures (JHT, 135, 061202, 2013). These approaches provide a path forward to process‐based design of functional porous materials for vapor chamber applications unconstrained by the availability of extant empirical data for established structures and fabrication techniques.
Justin Weibel is a Research Assistant Professor in the School of Mechanical Engineering at Purdue University and serves as the Associate Director of the Cooling Technologies Research Center (CTRC), an NSF I/UCRC that addresses research and development needs of companies and organizations in the area of high-performance heat removal from compact spaces. He received his PhD from Purdue University in 2012, and his Bachelor of Science in Mechanical Engineering from Purdue University in 2007. Dr. Weibel’s research interests include electronics cooling and packaging, phase-change transport phenomena, multiphase thermal systems, transport in porous materials, and energy efficient thermal management. He recently investigated the development of ultra-thin vapor chamber devices for high heat flux generating applications as part of the DARPA Thermal Ground Plane program (Phase I-III, 2008-2012), and received the 2011 ASME Electronic & Photonic Packaging Division (EPPD) Student Member of the Year Award. Dr. Weibel’s current research focuses on intrachip microchannel evaporative cooling as part of Purdue University’s MicroICE effort (Phase I, 2013-2015) supported by the DARPA ICECool Fundamentals program, as well as studies on porous media-based heat exchanger surfaces, boiling enhancement structures, ultra-thin heat pipes, and droplet evaporation/condensation dynamics.
#6: Nanophononic Materials
Nanophononic Metamaterial: Energy Harvesting with Nanoscale Heat Brakes
Thermoelectric materials convert heat into electricity or vice versa. They can be used to capture ambient or waste heat in numerous applications (such as power plants, spacecrafts, cars, electronic devices) and convert this heat into electricity. Alternatively these materials can be used to provide solid-state heating or cooling (air conditioning or refrigeration) using an electrical source. The performance of a thermoelectric material is measured by its so-called “ZT” figure of merit. One condition that allows a thermoelectric material to have a high ZT value is to be a good conductor of electricity and a poor conductor of heat. It is, however, very challenging to simultaneously realize these two properties in existing materials. For example, metals are good conductors of both heat and electricity and hence are poor thermoelectric materials. A significant advance in the value of the ZT–to above 3 in order to outperform traditional fluid-based technologies–for a reasonably low-cost material will spark a revolution in energy conversion across many industries in light of the tremendous economic and environmental benefits.
Here we present the concept of a locally resonant nanophononic metamaterial  for thermoelectric energy conversion. One possible configuration for this new material is based on a silicon thin-film (sheet) with a periodic array of nanoscale pillars erected on one or two of the free surfaces. Heat is transported in this nanostructured material as a succession of propagating vibrational waves, known as phonons. The atoms making up the minuscule pillars on their part generate stationary vibrational waves. These two types of waves, the travelling and the standing, interact and in doing so cause a substantial portion of the energy of the heat carrying phonons to divert into the pillars and effectively get trapped there. This in turn reduces the group velocities of the phonons and hence the thermal conductivity along the thin film. This novel phenomenon is practically independent of the mechanisms concerned with the generation and carrying of electrical charge and is therefore not expected to affect the electrical conductivity.
Using an experimentally-fitted lattice-dynamics model, we conservatively predict a drop in the metamaterial thermal conductivity to as low as 50% of the corresponding uniform thin-film value. And with optimization of dimensions, the reduction is expected to greatly increase further. In summary, we have shown that heat transfer in a crystalline material can be slowed down by mechanical vibrations, which on its own represent a fundamental new result in material physics. The implications on thermoelectric energy conversion, and renewable energy in general, are profound.
Mahmoud I. Hussein is an Associate Professor in the Department of Aerospace Engineering Sciences at the University of Colorado Boulder. He received B.S. and M.S. degrees in Mechanical Engineering from the American University in Cairo (1994) and Imperial College, London (1995), respectively. He also received two M.S. degrees (Applied Mechanics, 1999 and Mathematics, 2002) and a Ph.D. degree (Mechanical Engineering, 2004) from the University of Michigan, Ann Arbor. Following his graduate studies, Dr. Hussein spent a year and a half as a postdoctoral fellow at the University of Michigan, and two years as a research associate at the University of Cambridge’s Department of Engineering. His research focuses on the dynamics of materials and structures with particular attention on periodic materials at both the continuum and atomistic scales. Among his areas of interest are phononics and lattice dynamics of silicon-based nanostructured materials. His studies are concerned with physical phenomena governing these systems and relevant theoretical treatments. He has a special interest in the effects of dispersion, resonance, dissipation and nonlinearity. Recently he has also been conducting experiments to support the theoretical work. Among his honors is the 1st Prize Award at the Student Paper Competition at the annual meeting of the Society of Engineering Science in 2003, and the Robert J. Melosh Medal for Best Student Paper on Finite Element Analysis in 2005. In 2011, he was awarded a DARPA Young Faculty Award which aims “to identify and engage rising research stars in junior faculty positions at U.S. academic institutions”. In 2013, he was awarded an NSF CAREER award from the Mechanics of Materials program at the foundation. Dr. Hussein has served as guest editor for two special journal issues on phononic materials and structures. He has authored or co-authored 3 book chapters and over 60 papers in archival journals and peer-reviewed conference proceedings, and since 2006 has co-chaired over 15 symposia on “phononic crystals and acoustic metamaterials” at ASME and/or USNCM conferences. He co-chaired Phononics 2011 (Santa Fe, New Mexico, May 29-June 2, 2011; www.phononics2011.org) and Phononics 2013 (Sharm El-Sheikh, Egypt, June 2-7, 2013; www.phononics2013.org). The Phononics 20xx conference series is the world’s premier event in the emerging field of phononics.
Phononics: Nanoengineering Materials for Thermal Transport
Nanostructuring leads to unique material properties and combinations of properties not typically found in bulk materials. Of particular interest is the ability to tune the thermal transport properties through nanostructuring yielding high conductivity materials such as carbon nanotube forests for dissipating power in electronic devices and low conductivity materials like porous silicon for thermal barrier coatings and enhanced thermoelectric performance. This Technology/Science Update Talk will focus on methods to push the thermal conductivity of nanostructured materials to the extremes by understanding and controlling the phonon transport at the nanoscale.
Amy Marconnet is an assistant professor of Mechanical Engineering at Purdue University. She received a B.S. in Mechanical Engineering from the University of Wisconsin – Madison in 2007, and an M.S. and a PhD in Mechanical Engineering at Stanford University in 2009 and 2012, respectively. She then worked as a postdoctoral associate at the Massachusetts Institute of Technology, before joining the faculty at Purdue University in 2013. Research in the Marconnet Thermal and Energy Conversion Lab (M-TEC) integrates metrology and analysis of underlying transport mechanisms with design and development of nanostructured materials for heat transfer and energy conversion applications.
#7: Beyond Classical Scaling: Alternative Path towards Energy Efficient Systems
Orthogonal Scaling: The Future Path for Denser and Yet More Efficient Systems
Every 10 to 15 years, the information technology is transformed fundamentally. Currently, the amount of unstructured data collected through the cloud is growing exponentially. Cognitive Computing will provide insights from Big Data. Systems with high computational performance and a vast amount of memory will be key. However, benefits from classical scaling are diminishing and energy costs are getting significant. A strong correlation between system density and energy efficiency was shown. Hence, Orthogonal Scaling, including packaging for future system scaling is proposed. Concepts towards true 3D integration with scalable power delivery, heat removal and communication will be discussed, improving proximity and enabling novel 3D micro-architectures.
Thomas Brunschwiler is a research staff member of the advanced micro integration team at IBM Research – Zurich. He conducts physical research and coordinates governmental and joint projects. In this respect he is pushing the frontiers in 3D integration with respect to scalable heat removal and power delivery, supporting performance and efficiency scaling of high end servers. In this context he performed his Ph.D. in Electrical Engineering at the Technical University of Berlin, entitled “Interlayer Thermal Management of High-Performance Microprocessor Chip Stacks”. Thomas Brunschwiler authored and co-authored over 50 publications, one book chapter and over 25 patents. He is in the committee of several technical conferences and is a Senior Member of IEEE.
3D Stacking as an Enabler for Low-Power High-Performance Computing
Energy efficiency is a central issue in computing. In large-scale computing clusters, operational and cooling costs impose significant sustainability challenges. Embedded systems run increasingly complex, performance demanding workloads, making the well-known energy management policies inadequate. High power densities also cause high on-chip temperatures and large thermal variations, both of which degrade system reliability.
The main goal of this talk is to demonstrate that 3D stacked systems can provide dramatic increases in energy efficiency. Realizing this ambitious energy efficiency goal requires novel analysis, design, and runtime management techniques. This talk provides an overview of the catalyst techniques that make 3D systems effective agents for attaining low-power high-throughput computing in both embedded and large-scale computing domains. Specifically, the talk will discuss how to develop widely applicable temperature and full-system modeling techniques, design and management of logic-memory stacking, using logic-logic stacking as a means for creating “flexible heterogeneity”, and the benefits and challenges of liquid-cooled 3D systems.
Ayse K. Coskun is an assistant professor in the Electrical and Computer Engineering Department at Boston University. She received her MS and PhD degrees in Computer Science and Engineering from University of California, San Diego. Coskun’s research interests are temperature and energy management, 3D stack architectures, computer architecture, embedded systems, and data center energy efficiency. Prof. Coskun worked at Sun Microsystems (now Oracle), San Diego prior to her current position at BU. She received the best paper award at IFIP/IEEE VLSI-SoC Conference in 2009 and at High Performance Embedded Computing (HPEC) Workshop in 2011, and she is a recipient of the NSF CAREER award. She has served as an associate editor for ACM Transactions on Design Automation of Electronic Systems and IEEE Embedded Systems Letters. Coskun also writes a bi-monthly column on green computing for the Circuit Cellar magazine.