MEAM Seminar Series Spring 2016
For Fall 2015 Seminars, click here.
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).
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Monday, January 11: Special Seminar
James Pikul, Post-Doctoral Associate, Department of Mechanical and Aerospace Engineering, Cornell University
9:00 am, Wu and Chen Auditorium
"Design and Fabrication of High Power Microbatteries and High Specific Strength Cellular Solids from Mesostructured Hierarchical Materials"
An emerging paradigm in engineering design is the development of materials by constructing hierarchical assemblies of simple building blocks into complex architectures that address physics at multiple length scales. These hierarchical materials are increasingly important for the next generation of mechanical, electrical, chemical, and biological technologies. However, fabricating hierarchical materials with nm control over multiple chemistries in a scalable fashion is a challenge yet to be overcome. This talk reports the design and fabrication of hierarchical microbattery electrodes that demonstrate unprecedented power density as well as large area cellular solids with controllable moduli and high specific strengths.
The microbatteries have up to 7.4 mW cm-2 m-1 power density, which equals or exceeds that of the best supercapacitors and is 2000 times greater than other microbatteries. The three-dimensional bicontinuous interdigitated microelectrode architecture improves power performance by simultaneously controlling ion and electron transport distances through the anode, cathode, and electrolyte. The low internal transport resistances reduce the microbattery internal heat generation by more than 50% at normal (0.1 – 10 C) discharge rates. Self-assembly and electrochemical deposition techniques integrate large volume fractions of high capacity materials into the microbattery architecture to enable up to 45.5 µWh cm-2 µm-1 energy densities, which is greater than previously reported three-dimensional microbatteries and comparable to commercially available lithium-based batteries, while maintaining high power density. A one dimensional electrochemical model of the microbatteries enables the development of battery design rules that suggest a 10X improvement in battery power performance is possible.In addition, the electrode architecture has high specific compressive strengths up to 0.23 MPa / (kg m−3) and Young’s moduli that can be varied from 2.0 to 44.3 GPa. The specific strength is greater than most high strength steels and titanium alloys and is due to the size based strengthening of the nanometer scale struts in the porous architecture. The excellent mechanical properties, combined with the ability to precisely control chemistry, can be utilized to develop next generation multifunctional materials for energy, robotics, and medical applications.
James Pikul earned his B.S. (2009) M.S. (2011) and Ph.D. (2015) in Mechanical Engineering from University of Illinois at Urbana-Champaign under the advisement of Professors William P. King (Mechanical Engineering) and Paul V. Braun (Materials Science). He was a Department of Energy Office of Science Graduate Research Fellow and University of Illinois Carver Fellow. His Ph.D. research focused on the self-assembly and electrochemical fabrication of ultra-high power microbatteries and large area, high strength cellular solids. For this work, he won the Materials Research Society Gold Award. James has authored nine journal papers, four conference papers, and a patent application. His articles inNature CommunicationsandPNAShave generated significant interest in the popular media, having been featured in BBC, Discovery News, Yahoo News, arstechnica, Engadget, and many other outlets. James Pikul is currently a post-doctoral scholar in the Organic Robotics Laboratory at Cornell University under Professors Robert Shepherd (Mechanical Engineering) and Itai Cohen (Physics). In this position, he continues to develop advances in multi-scale manufacturing to enable critically important technologies. He is currently developing soft robotic rovers for extraterrestrial oceans for NASA and manufacturing technologies for adaptive camouflage for the US Army.
Cynthia Sung, PhD Candidate, Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology
"Computational Tools for Robot Design: A Composition Approach"
As robots become more prevalent in society, they must develop an ability to deal with more diverse situations. This ability entails customizability of not only software intelligence, but also of hardware. However, designing a functional robot remains challenging and often involves many iterations of design and testing even for skilled designers. My goal is to create computational tools for making functional machines, allowing future designers to quickly improvise new hardware in response to unexpected circumstances.
In this talk, I will discuss one possible approach to automated design using composition. I will describe our origami-inspired print-and-fold process that allows entire robots to be fabricated within a few hours, and I will demonstrate how foldable modules can be composed together to create foldable mechanisms and robots. The modules are represented parametrically, enabling a small set of modules to describe a wide range of geometries and also allowing geometries to be optimized in a straightforward manner. I will also introduce a tool that we have developed that combines this composition approach with simulations to help human designers of all skill levels to design and fabricate custom functional robots.
Cynthia Sung is a Ph.D. candidate in the Computer Science and Artificial Intelligence Laboratory at the Massachusetts Institute of Technology (MIT). She received a B.S. in Mechanical Engineering from Rice University in 2011 and an M.S. in Electrical Engineering and Computer Science from MIT in 2013. Her research interests include computational design, folding theory, and rapid fabrication, and her current work focuses on algorithms for synthesis and analysis of engineering designs.
Thursday, January 28: Special Seminar
Arthur W. Mahoney, Postdoctoral Fellow in the Medical Engineering and
Discovery Laboratory at Vanderbilt University
1:30 p.m. - 2:30 p.m., Singh Center for Nanotechnology, 3205 Walnut Street, Glandt Forum (third floor)
"Wireless Magnetic Devices and Needle-sized Tentacles Inside the Body: Robots That Help Surgeons Save Lives"
Robotic technology has transformed the operating room by giving surgeons access to confined regions of the human body with dexterity as good as their own hands. But there are still areas of the human body that surgeons consider to be “inoperable” in a safe way. This talk is about emerging robotic technologies that push the frontiers of where robots can reach in the human body. My talk will cover how the physics of magnetism and elasticity can be exploited to create miniature magnetic wireless robots that navigate through the pathways of the human body, and needle-sized elastic tentacle robots that can maneuver around corners to deliver dextrous tools without any incisions in the skin. These devices can become interactive diagnostic and interventional instruments that push the boundaries ofinoperable disease when they are combined with perception and intelligence. A major theme of this talk is that the robots in the future operating room must be "smart- by-design,"that is, mechanically designed with perception and intelligence in mind.
Dr. Art Mahoney is a Postdoctoral Fellow in the Medical Engineering and Discovery Laboratory at Vanderbilt University. He earned undergraduate degrees in computer science and computational mathematics from Utah State University, and his Ph.D. degree from the School of Computing at the University of Utah as a member of the Utah Telerobotics Laboratory. His graduate research was on magnetically controlled robots in the human body with Dr. Jake Abbott. Dr. Mahoney’s postdoctoral work focuses on design, planning, and sensing for flexible minimally-invasive surgical robots with Dr. Robert Webster. Aside from his postdoctoral and graduate work, he has conducted research in computational search methods for discovering new cancer therapies, parallel computing, and robot motion planning. He is the recipient of an NSF Graduate Research Fellowship and is a Hertz Fellowship Finalist.
Rodrigo A. Bernal, Postdoctoral Researcher, Department of Mechanical Engineering and Applied Mechanics,
University of Pennsylvania
"Mechanical and Electromechanical Properties of Nanowires for Sensors and Electronics"
Nanowires are envisioned as components of future sensors, electronics, nanostructured materials, among many applications. This technological relevance has stimulated research in the characterization and understanding of their physical properties. In this talk, I will present results on the mechanical and electromechanical characterization of metallic and semiconducting nanowires, obtained with in-situ electron microscopy experiments. By allowing visualization of the materials at high resolution during characterization, in-situ experiments allow us to draw insights on the fundamental mechanisms controlling nanowire properties.
In the context of semiconducting specimens, we characterized the elastic modulus of gallium nitride nanowires. We find that below 20 nm in diameter, the nanowires display enhanced elastic modulus, due to reduced interatomic spacing near the surface. For metallic specimens, we characterized the tensile behavior of fivefold-twinned silver nanowires below 120 nm in diameter. We observe the Bauschinger effect and recoverable plasticity, and establish these behaviors are caused by reversible dislocation activity promoted by the twinned structure. For both semiconducting and metallic specimens, complementary atomistic simulations agree with the experimental results. Leveraging the experience acquired on mechanical testing, we implemented a MEMS (Microelectromechanical System) device for electromechanical characterization. We characterized the piezoresistance of n-doped silicon nanowires, which is found to be of the same order of magnitude as bulk.
The ability to characterize both the mechanical properties of nanomaterials, and the effect of mechanical deformation on other properties, such as electron transport, will pave the way for the discovery of novel multiphysics phenomena, which will underpin the next generation of sensors and electronics.
Rodrigo Bernal was born and raised in Colombia. He earned B.Sc. degrees in Mechanical and Electronics Engineering from the University of the Andes, in Bogotá. After this, he moved to the U.S to pursue a Ph.D. in Mechanical Engineering at Northwestern University, under the advisement of Prof. Horacio Espinosa, graduating in 2014. At Northwestern, he investigated the mechanical and electromechanical properties of metallic and semiconducting nanowires, employing in-situ Scanning and Transmission Electron Microscopy (SEM/TEM). Currently, he is a postdoctoral researcher in the Mechanical Engineering and Applied Mechanics Department, at the University of Pennsylvania, supervised by Prof. Robert Carpick. He is investigating the fundamental mechanisms of wear and friction in advanced carbon-based materials. His future research interests are in the area of nanomechanical multiphysics: nanoscale phenomena where mechanical deformation can control and tune other properties such as electrical, thermal or chemical.
Monday, February 8: Special Seminar
Jordan R. Raney, Postdoctoral Fellow,Wyss Institute for Biologically Inspired Engineering, Harvard University
"Mechanics By Design: 3D Printing Architected Engineering Materials With Unprecedented Control of Mechanical Properties"
Natural structural materials such as wood possess highly heterogeneous mesoscale architectures, with hierarchical structure, spatially-varying fiber alignment, non-uniform density, graded porosity, and multifunctionaliMty. These features are the result of localized structural and compositional optimization, producing maximal bulk mechanical properties that greatly exceed those of the constituent materials. In contrast, due to the limitations of current manufacturing processes, synthetic engineering materials typically lack these heterogeneous features that are associated with optimized mesoscale structure. As a result, they lack the level of performance (as defined by metrics such as strength, toughness, mass efficiency, etc.) that is ultimately possible. Additive manufacturing techniques have begun to enable more complicated mesoscale features in synthetic material systems, but many challenges remain. Here, direct write 3D printing is applied to the construction of architected engineering materials with the goal of enabling unprecedented control of mechanical properties. Two example material systems will be discussed: (i) beam-based soft materials that make use of bistability to controllably store and release elastic strain energy; and (ii) bioinspired fiber composites with fiber alignment that can be locally, heterogeneously assigned to achieve excellent mass efficiency and control of strain and failure localization.
Jordan R. Raney is a Postdoctoral Fellow in the John A. Paulson School of Engineering and Applied Sciences and the Wyss Institute for Biologically Inspired Engineering at Harvard University. His research focuses on the mechanics and fabrication of novel material architectures, including hierarchical, heterogeneous, fibrous, and soft systems. He received his Ph.D. in materials science at the California Institute of Technology, where he was the recipient of a National Defense Science & Engineering Graduate Fellowship and the Demetriades-Tsafka-Kokkalis Prize in Nanotechnology for his dissertation.
Jeremy D. Brown, Postdoctoral Research Fellow, Department of Mechanical Engineering and Applied Mechanics, University of Pennsylvania
"Smart Haptic Displays for Dextrous Manipulation of Telerobots"
The human body is capable of dexterous manipulation in many different environments. Some environments, however, are challenging to access because of distance, scale, and limitations of the body itself. In many of these situations, access can be effectively restored via a telerobot, in which a human remotely controls a robot to perform the task. Dexterous manipulation through a telerobot is currently limited, and will be possible only if the interface between the operator’s body and the telerobot is able to accurately relay any sensory feedback resulting from the telerobot’s interactions in the environment.
This talk will focus on the scientific investigation of high fidelity haptic interfaces that adequately translate the interactions between the telerobot and its environment to the operator’s body through the sense of touch. I will introduce the theme of “Smart Haptic Displays,” which are capable of modulating their own dynamic properties to compensate for the dynamics of the body and the telerobot to ensure the environment dynamics are accurately presented to the operator. Along the way, I will highlight contributions I have already made for two specific telerobots: upper-limb prostheses and minimally invasive surgical robots. These contributions include an empirical validation of the utility of force feedback in body-powered prostheses and the creation of a testbed to compare various haptic displays for pinching palpation in robotic surgery. Finally, I will briefly introduce a novel approach I am currently investigating that utilizes haptic signals to automatically predict a surgical trainee’s skill on a minimally invasive surgical robotic platform. As this work progresses, it will lead to the creation of interfaces that provide the rich haptic sensations the body has come to expect, and will allow for dexterous manipulation in any environment whether or not access is mediated through a telerobot.
Jeremy D. Brown is a Postdoctoral Research Fellow in the Department of Mechanical Engineering and Applied Mechanics and the Haptics Group in the GRASP Lab at the University of Pennsylvania. He earned undergraduate degrees in applied physics and mechanical engineering from Morehouse College and the University of Michigan, and a PhD degree in mechanical engineering from the University of Michigan, where he worked in the HaptiX Laboratory. His research focuses on the interface between humans and robots with a specific focus on medical applications and haptic feedback. He was honored to receive several awards including the National Science Foundation (NSF) Graduate Research Fellowship and the Penn Postdoctoral Fellowship for Academic Diversity.
Thursday, February 18: MEAM Special Seminar
Christopher Boyce, Post-doctoral researcher at Princeton University in the Multiphase Flow Group in the Department of Chemical and Biological Engineering
" Tomographic Imaging and Computational Modeling of Fluid-Particle Flow Systems"
Fluid-particle flows exhibit fascinating and complex physical phenomena which defy the traditional divisions between solid, liquid and gas. These flows also form the basis of many process units, such as fluidized beds, which perform vital operations in industries ranging from fuel and electricity generation to polymer production to pharmaceutical manufacturing. Recent and renewed attention focuses on their potential in providing clean energy solutions, for example, in chemical looping combustion, a process for burning coal, natural gas and biomass with efficient carbon capture. Fluidized beds and other fluid-particle flow systems are widely used because their dynamics allow for efficient particle transport and mixing as well as interphase heat and mass transport. These dynamics also create fascinating physical phenomena, such as bubbles rising through granular material in a liquid-like state, and hydrodynamic effects coupled with chemical reactions, species transport and inter-particle forces generate a range of multi-physics problems. With such complex dynamics, we have only begun to scratch the surface of understanding the fundamental science of these systems, despite decades of industrial use.
Two historic limitations in scientific research of fluid-particle flow systems have been: (1) a lack of non-invasive experimental techniques for measuring the multi-physics of these opaque, 3D systems and (2) difficulties in developing models which account for the various physics of these systems on all of the necessary length and time scales. Exciting advances in tomographic imaging and computational modeling have now opened the door to provide crucial new insights into the governing physics, statistics and evolution of these flow systems. This talk will center on the advancement and use of magnetic resonance imaging (MRI) to study the hydrodynamics of the gas and solid phases, as well as multi-scale modeling techniques accounting for complex inter-particle forces.
Chris Boyce is a post-doctoral researcher at Princeton University in the Multiphase Flow Group in the Department of Chemical and Biological Engineering. He studied as an undergraduate at MIT, earning a double-major in Chemical Engineering and Physics with a minor in Nuclear Science and Engineering. As a Gates Cambridge Scholar, he obtained his PhD at the University of Cambridge in Chemical Engineering as a member of Trinity College. Chris has been studying the science underlying energy-related systems since he was an undergraduate and has acquired expertise in uncovering the physics of fluidization using magnetic resonance imaging (MRI) coupled with multiscale modeling.
April 19: Tedori-Callinan Seminar
Albert P. Pisano, NAE, Walter J. Zable Chair of Mechanical and Aerospace Engineering and Dean, Jacobs School of Engineering, University of California, San Diego
In this seminar, recent results in the dry nanoprinting of a number of structures and devices will be presented. Dry nanoprinting is a novel process by which a micro or nanofluidic template is used not only to guide the flow of one or more inks simultaneously, but also to template the final, dry printed structures and devices. The advantages of this approach include auto-registration among structures printed from multiple iinks, as well as extreme sidewall definition. Examples of functional devices made from this technology will be presented.
Albert P. Pisano began his service as Dean of the Jacobs School of Engineering on September 1, 2013. Pisano holds the Walter J. Zable Chair in Engineering and serves on the faculty of the Departments of Mechanical and Aerospace Engineering and Electrical and Computer Engineering.
Pisano is an electred member of the National Academy of Engineering for contributions to the design, fabrication, commercialization, and educational aspects of MEMS.
Prior to his appointment at UCSD, Pisano served on the UC Berkeley faculty for 30 years where he held the FANUC Endowed Chair of Mechanical Systems. Pisano was the senior co-director of the Berkeley Sensor & Actuator Center (an NSF Industry-University Cooperative Research Center), director of the Electronics Research Laboratory (UC Berkeley's largest organized research unit), and faculty head of the Program Office for Operational Excellence, among other leadership positions. Since 1983, Pisano has graduated over 40 Ph.D. and 75 M.S. students.
From 1997 to 1999, Pisano was a program manager for the MEMS Program at the Defense Advanced Research Project Agency (DARPA).
Pisano earned his undergraduate ('76) and graduate degrees ('77, '80, '81) in mechanical engineering at Columbia University. Prior to joining the faculty at UC Berkeley, he held research positions with Xerox Palo Alto Research Center, Singer Sewing Machines Corporate R&D Center and General Motors Research Labs.
Pisano's research interests include: micro-electro-mechanical systesm (MEMS) wireless sensors for harsh environments (600 degrees Celsius) such as gas turbines and geothermal wells; and additive, MEMS manufacturing techniques such as low-temperature, low-pressure nano-printing of nanoparticle inks and polymer solutions. Other research interests and activities include MEMS for a wide variety of applications, including RF components, power generation, drug delivery, strain sensors, biosensors, micro inertial instruments, disk-drive actuators and nanowire sensors. He is a co-inventor listed on more than 20 patents in MEMS and has co-authored more than 300 archival publications.
Pisano is a co-founder of ten start-up companies in the areas of transdermal drug delivery, transvascular drug delivery, sensorized catheters, MEMS manufacturing equipment, MEMS RF devices and MEMS motion sensors.