Penn Engineering Events

MSE Grace Hopper Lecture: "Optics on the Nanoscale: Conquering Absorption with Nonlinear Optics"
2021-10-28 12:30 - 13:30 (America/New_York) | Auditorium, LRSM Building, 3231 Walnut Street, Philadelphia, PA, 19104, United States
Optical nanostructures enable molding the flow of light on the subwavelength scale rendering possible the realization of compact, cost-effective, flat and highly efficient optical components for imaging, spectroscopy, sensing, and communications. From the fundamental science viewpoint, light-matter interactions at the nanoscale reveal themselves in new and often unexpected ways. In fact, the usual linear and nonlinear macroscopic theories that describe the behavior of the electromagnetic field merit revision. From the applications viewpoint, miniaturized, tunable and reconfigurable functionalities implemented on a chip are of paramount importance. Here, we reassess dielectric materials such as chalcogenides as promising candidates for science and applications in wavelength ranges once thought to be hostile to the propagation of light. We show that, in fact, these materials constitute new, excellent contenders for developing new, multi-functional nanophotonic devices due to their high linear refractive indices, strong nonlinear response, and fast switching speeds. To date, applications of these glasses have been limited to wavelength ranges where absorption meticulously avoided, for example, above 500nm for As2S3: high absorption at visible and ultraviolet wavelengths manifests itself through the large imaginary parts of the dielectric constants. However, we demonstrate that, as counterintuitive as it may appear, highly nonlinear, properly nanostructured chalcogenide glass, transparent in the mid- and near-infrared, can also be used to generate third harmonic frequencies in the visible and ultraviolet part of the spectrum, despite the presence of strong material absorption in this range. Such third-harmonic generation can be tuned and further enhanced using stacked metasurfaces and various mechanisms of local field enhancement, including Mie and quasi-bound states in continuum resonances.

ESE Fall Colloquium Seminar - "Transforming Ideas to Reality: Emerging Nanotechnologies from the “Lab” to the “Fab”"
2021-10-28 10:30 - 11:30 | Raisler Lounge (Room 225), Towne Building, 220 South 33rd Street, Philadelphia, PA, 19104, United States
Emerging nanotechnologies promise to enable a wide-range of next-generation applications – from energy-efficient computing to personalized healthcare. Yet many emerging nanotechnologies face substantial inherent imperfections and variations that have rendered making working systems – and therefore the next-generation applications they promise to enable – infeasible. In this talk, I will describe how by computing advances across the entire stack – from nanomaterial synthesis to new processing techniques, circuit design methodologies, architectures, and novel systems – these challenges can be overcome to realize the first large-scale and complex electronic systems leveraging beyond-silicon emerging nanotechnologies. As a case-study, I will describe the journey of transforming carbon nanotubes from an interesting scientific nanomaterial in academic labs into the foundation for realizing novel systems and applications that can impact our daily lives, such as the first beyond-silicon microprocessor for energy-efficient computing and novel diagnostic tools for rapid and accurate disease diagnostics. I will conclude by describing how these emerging nanotechnologies are currently being transferred from the “lab” to multiple commercial “fabs”, promising a new and exciting age for electronics and the systems and applications they can enable.

ODEI Spotlight: Society of Women Engineers GSK Info Session
2021-10-27 18:00 - 19:00 | PA
Society of Women Engineers GSK Info Session
Wednesday, October 27 from 6-7 PM

GSK is hosting an information session for students of all grade levels! GSK is hiring for the Internship and Co-Op Program, and the Future Leaders Program! If you are interested in applying what you are learning in your current classes in real-life work scenarios, an internship or co-op is the perfect opportunity for you to do so! If you are coming up on graduation, the Future Leaders Program is a rotational training program that will provide you with the skills you need to succeed!

Join us to learn more about GSK’s programs, and what it is like to work here. We look forward to seeing you there!

When: October 27 at 6 PM
Where: Microsoft Teams (tinyurl.com/swe-gsk)

Fall 2021 GRASP SFI: “Physics-inspired learning for discontinuous contact dynamics”
2021-10-27 15:00 - 16:00 | Levine 307, 3330 Walnut Street, Philadelphia, PA, 19104, United States
*This will be a HYBRID Event with in-person attendance in Levine 307 and Virtual attendance via Zoom here…
Frictional contact is the core underlying behavior of robot locomotion and manipulation, and its nearly-discontinuous dynamics make planning and control challenging even when an accurate model of the robot is available. In this talk, I will first present empirical evidence that learning an accurate model in the first place can be confounded by contact, as modern deep learning approaches are not designed to capture this non-smoothness. Second, I will discuss ContactNets, our approach which circumvents this conflict via a smooth, implicit encoding of discontinuity as signed distance functions and contact-frame Jacobians.

ODEI Spotlight: Diversity Lecture Series at Penn, "Addressing a More Complex and Encompassing Understanding of Identity"
2021-10-27 12:00 - 13:00 | PA
Speaker: Melissa E. Sanchez, Ph.D.
Center for Research in Feminist, Queer, and Transgender Studies
Topic: Addressing a More Complex and Encompassing Understanding of Identity
Date: Wednesday, October 27, 2021
Time: 12 Noon to 1:00 PM
Link: : https://upenn.zoom.us/j/93398784741?pwd=[REDACTED]

MEAM Seminar: “Robotics Goes Soft: Challenges and Achievements, for New Robotics Scenarios”
2021-10-26 10:00 - 11:30 | Zoom – Email MEAM for Link, peterlit@seas.upenn.edu
Largely inspired by the observation of the role of soft tissues in living organisms, the use of soft materials for building robots is recognized as one of the current challenges for pushing the boundaries of robotics technologies and building robotic systems for service tasks in natural environments. The study of living organisms sheds light on principles that can be fruitfully adopted to develop additional robot abilities or to facilitate more efficient accomplishment of tasks, because living organisms exploit soft tissues and compliant structures to move effectively in complex natural environments.
Widely growing worldwide, soft robotics has produced already interesting achievements in terms of technologies for actuation, sensing, control, and many more. In addition to allowing more applications for robots, soft robotics technologies are enabling robot abilities that were not possible before, like morphing, stiffening, growing, self-healing, evolving. They open up new scenarios for robotics that brings towards more life-like robots, effectively and efficiently adaptable to their environments and tasks.

CBE PhD Dissertation Defense | “Process Development and Modeling for the Advancement of Direct Air Capture Technologies"
2021-10-25 15:00 - 17:00 | Zoom – Email CBE for link
Abstract:
“As the catastrophic effects of climate change are felt throughout our global society, we must take immediate action. A portfolio of climate solutions must include both deep and robust decarbonization, and systems to remove carbon dioxide directly from the atmosphere. One promising suite of carbon removal technologies is Direct Air Capture (DAC). DAC refers to engineered systems that pull CO2 from air, capturing it in a near-pure form. The captured CO2 can be stored geologically (resulting in a reduction of atmospheric CO2 concentrations), or otherwise utilized. This Dissertation focuses on development and deployment of DAC technologies first by exploring the current DAC landscape, then by proposing a novel DAC process using earth-abundant minerals.

The current landscape of DAC includes two main approaches: solid sorbent and liquid solvent. Each DAC approach has advantages and challenges, including energy usage, specialty chemical demand, and land area requirements. Here, each approach is outlined, and suggestions are provided to accelerate industrial deployment. Additionally, the effect of different dedicated energy infrastructure to power solvent-based DAC is evaluated, including both fossil and renewable energy resources and quantifying the effect of energy-related emissions on the amount of carbon net removed from air. A technoeconomic tool is also presented which allows for a high-level cost estimate of DAC based on available information. The tool can be utilized by investors to evaluate key aspects of DAC technologies and determine which innovations result in significant cost reductions.

An ambient oxide looping process is proposed as a novel approach to DAC. The process uses earth-abundant minerals (limestone, magnesite) to produce reactive oxides (calcium oxide, magnesium oxide) that react with the CO2 in air. Investigation into the economics of the process indicates it could be less expensive per ton of CO2 removed than other DAC technologies. To understand the process viability, a series of experiments characterize industrially available calcium and magnesium oxide and hydroxide feedstocks. These experiments probe the physical properties of these materials and different aspects of engineering optimization, including material depth and rate enhancement as a function of both relative humidity and direct water addition to the system. “

PICS Colloquium: "Kinetic theory for superparameterization of sea ice dynamics"
2021-10-22 14:00 - 15:00 | PICS Conference Room 534 – A Wing , 5th Floor, 3401 Walnut Street, Philadelphia, PA, 19104, United States
Arctic sea ice comprises of many ice floes whose dynamics is driven by oceanic/atmospheric currents and floe-floe interaction. Models of the effective sea ice dynamics at large scales typically employ hydrodynamic equations of motion, such as mass and momentum conservation, with complex constitutive laws attempting to capture the rheology of sea ice as a continuum. Although hydrodynamic sea ice models have enjoyed some successes, they have well-documented limitations in capturing phenomena such as fracture and lead formation, which are direct manifestation of the granular nature of sea ice.
In this talk, we describe a framework that generalizes hydrodynamic models for sea ice using a mesoscopic (kinetic) description that systematically couples macro-scale PDEs with small-scale particle methods. This framework employs a time-dependent probability distribution over floe position and velocity, evolving according to the Boltzmann equation. The mass density and momentum (computed by integrating over the velocity coordinate) evolve according to the same macro-scale hydrodynamic equations used in previous models. However, rather than requiring an effective rheology, kinetic models of the collisions between co-located ice particles determine the small-scale evolution of the conditional density and influence the macro-scale dynamics. To simulate this system efficiently, we construct a two-tiered numerical method that employs finite element methods to solve the macro-scale PDEs and a particle method to evolve the conditional density over the velocity coordinate. We illustrate the framework with idealized numerical experiments demonstrating that it can naturally reproduce phenomena such as ice breakup under a divergent flow.

GRASP on Robotics: "The Importance of Pneumatic Actuation in Adaptive Robotic Devices"
2021-10-22 10:30 - 11:45 | PA
Abstract: Soft pneumatic actuators have become a popular implement in modern robotic systems due to their intrinsic mechanical compliance, which affords researchers levels of robustness and adaptability that can be difficult to achieve in rigid-body, motor-driven devices. However, with the physical advantages of these versatile actuators come significant challenges in sensing, feedback control, and sustainable, portable powering that can limit their feasibility in real-world applications. This talk will highlight the engineering challenges of pneumatic actuation within the context of ongoing robotics research efforts in the ARM Lab, including the development of a soft, EMG-controlled robotic knee exoskeleton. The implications of new pneumatic actuation approaches on the future of smart, wearable human augmentation systems will also be discussed.

BE Seminar: "Phage and Robotics-Assisted Biomolecular Evolution" (Emma Chory)
2021-10-21 15:30 - 16:30 | Moore 216, 200 S. 33rd Street, Philadelphia, PA, 19104, United States
This seminar will be held live and broadcast on zoom – check email for link or contact ksas@seas.upenn.edu.
Evolution occurs when selective pressures from the environment shape inherited variation over time. Within the laboratory, evolution is commonly used to engineer proteins and RNA, but experimental constraints have limited our ability to reproducibly and reliably explore key factors such as population diversity, the timing of environmental changes, and chance. We developed a high-throughput system for the analytical exploration of molecular evolution using phage-based mutagenesis to evolve many distinct classes of biomolecules simultaneously. In this talk, I will describe the development of our open-source python:robot integration platform which enables us to adjust the stringency of selection in response to real-time evolving activity measurements and to dissect the historical, environmental, and random factors governing biomolecular evolution. Finally, I will talk about our many on-going projects which utilize this system to evolve previously intractable biomolecules using novel small-molecule substrates to target the undruggable proteome.

MSE Seminar: "Topological Physics: from Photons to Electrons"
2021-10-21 12:30 - 13:30 | Auditorium, LRSM Building, 3231 Walnut Street, Philadelphia, PA, 19104, United States
There are many intriguing physical phenomena that are associated with topological features — global properties that are not discernible locally. The best-known examples are quantum Hall effects in electronic systems, where insensitivity to local properties manifests itself as conductance through edge states which are insensitive to defects and disorder. In this talk, Dr. Hafezi will first discuss how similar physics can be explored with photons; specifically, how various topological models can be simulated in various photonics systems, from ring resonators to photonic crystals. He then will discuss that the integration of strong optical nonlinearity can lead to unique bosonic phenomena, such as topological frequency combs, topological source of quantum light and chiral quantum optics. These results may enable the development of classical and quantum optical devices with built-in protection for next-generation optoelectronic and quantum technologies. In the end, Dr. Hafezi will cover the topological interplay between photonic and electronic systems. Specifically, he investigates how light can create and manipulate topological states of electrons.

Singh Center for Nanotechnology 2021 Annual User Meeting
2021-10-21 08:00 - 19:30 | Glandt Forum, Singh Center for Nanotechnology, 3205 Walnut Street, Philadelphia, PA, 19104, United States

CBE Seminar: "Spatial and Dynamical Control in Metabolic Engineering Using Organelle Engineering and Optogenetics"
2021-10-20 15:30 - 16:30 | Wu and Chen Auditorium (Room 101), Levine Hall, 3330 Walnut Street, Philadelphia, PA, 19104, United States
Abstract
Metabolic engineering aims to rewire cellular metabolism, typically of microorganisms, to produce fuels, chemicals, pharmaceuticals, and other valuable products from renewable resources. However, it is often challenging to achieve the titers, yields, and productivities required for commercial viability. Spatial and dynamical control of engineered metabolic pathways can greatly improve their efficiency to address this obstacle. We have developed strategies to enhance the flux and specificity of metabolic pathways by spatially compartmentalizing them in yeast mitochondria and synthetic organelles. This helps increase the local concentrations of enzymes and intermediate metabolites, prevent metabolic bottlenecks, and reduce metabolite loss to competing pathways. In addition, I will present a new strategy to dynamically control metabolic pathways using optogenetics. There are many advantages of using light to control metabolic pathways, including its orthogonality, tunability, and the ease with which it can be applied or removed instantly in any schedule to continuously manipulate metabolism throughout fermentations. I will present several optogenetic circuits we have built to control microbial growth and production with light, the impact they have on chemical production, and the strategies we have developed to overcome the limited light penetration of fermentations operating at high cell density in lab scale bioreactors. Finally, I will provide a perspective on how these technologies may come together to prescribe a new paradigm for spatial and dynamical control in metabolic engineering to improve microbial chemical production.

Fall 2021 GRASP SFI: “Diversity and Inequality in Social Networks”
2021-10-20 15:00 - 16:00 | PA
Abstract: Online social networks often mirror inequality in real-world networks, from historical prejudice, economic or social factors. Such disparities are often picked up and amplified by algorithms that leverage social data for the purpose of providing recommendations, diffusing information, or forming groups. In this talk, I discuss an overview of my research involving explanations for algorithmic bias in social networks, briefly describing my work in information diffusion, grouping, and general definitions of inequality. Using network models that reproduce inequality seen in online networks, we’ll characterize the relationship between pre-existing bias and algorithms in creating inequality, discussing different algorithmic solutions for mitigating bias.
*This is a HYBRID Event with in-person attendance to watch the Zoom stream in Levine 307 and Virtual attendance via Zoom here…

ESE Fall Colloquium Seminar - "Distributed Estimation Under Privacy and Communication Constraints"
2021-10-19 11:00 - 12:00 | Zoom – Meeting ID: 282 221 4402
Distributed estimation is a central task in modern data science, where datasets are often generated from distributed sources or are too large to be stored on a centralized machine, and communication is subject to bandwidth and privacy limitations. In this talk, we will consider the problem of estimating high-dimensional distributions and their parameters from distributed samples under communication and differential privacy constraints. We will develop novel encoding and estimation mechanisms that simultaneously achieve optimal privacy and communication efficiency in various canonical settings, including both probabilistic and so called “distribution-free” models. We will investigate both global (worst-case) as well as local complexity of these tasks, where the latter captures the hardness of estimating a specific instance of the problem. We will complement our achievability results with information-theoretic lower bounds that describe how Fisher information from statistical samples scales with privacy and communication constraints. We will conclude by discussing how our theoretical results can be used to improve the experimental performance of federated learning algorithms.

MEAM Seminar: "Computational Mechanics for Landing on Mars"
2021-10-19 10:00 - 11:30 | Wu and Chen Auditorium (Room 101), Levine Hall, 3330 Walnut Street, Philadelphia, PA, 19104, United States
Current technology for decelerating a spacecraft from the high speed of atmospheric entry to the final stages of landing on Mars is based on low-density supersonic decelerators such as low mass and high packaging efficiency parachute systems. To enable future exploration missions featuring sophisticated robots and safely land heavier spacecraft on Mars, larger than before high-speed parachutes and inflatable drag devices are needed. The design, development, and maturing of such devices for future use at Mars require guidance from predictive simulations based on a high-fidelity, multi-disciplinary computational model for parachute inflation dynamics (PID) and drag prediction. The development of such a model is a formidable challenge. It must account for shocks, turbulence, and porous flow boundary conditions; the complexity of the behaviour of fabric material; massive contact between very thin surfaces; and highly nonlinear fluid-structure interactions in the presence of topological changes. The computational model must also be able to predict various instabilities of a parachute such as flutter and pulsation, the influence on its performance of several design factors including material and geometric porosities, and material failure. This lecture will discuss an ongoing effort at Stanford University, in collaboration with NASA Ames and the Jet Propulsion Laboratory, for the development of such a computational model and some associated computational innovations. These include: a multi-scale approach for modeling the dynamics of woven fabrics based on the concept of a locally attached microstructure and mechanics-informed machine learning; a discrete-event-free, spurious-oscillation-free, and total variation diminishing embedded boundary method for multi-material problems; a subgrid scale modeling approach for the treatment of porous wall boundary conditions; and an energy-conserving approach for the discretization of transmission conditions at the interface between fluid and structural representations of disparate spatial dimensions. The lecture will also report on validation results for the simulation of the supersonic inflation dynamics of: the parachute that landed Curiosity on Mars, on August 6, 2012; and those used in NASA’s 2018 ASPIRE tests to help decide which parachute design to use on the recent Mars 2020 mission that landed Perseverance on Mars, on February 18, 2021.

PSOC@Penn: Celeste Nelson
2021-10-18 12:00 - 13:00 | Raisler Lounge (Room 225), Towne Building, 220 South 33rd Street, Philadelphia, PA, 19104, United States
Room: Towne 225/Raisler Lounge
For zoom link, contact manu@seas.upenn.edu.

CBE Seminar: "The Refinery of Today, Tomorrow and the Future: A Separations Perspective"
2021-10-13 16:30 - 17:30 | Wu and Chen Auditorium (Room 101), Levine Hall, 3330 Walnut Street, Philadelphia, PA, 19104, United States
Abstract
The hydrocarbon processing industry is in the midst of a major shift in feedstocks, structure, and products. Aggressive carbon abatement targets and intrinsic efficiency advantages from electric vehicles strongly undercut the advantages of fossil fuels, which are the majority product of this industry. However, the immense value of the existing hydrocarbon infrastructure suggests that fossil feedstocks, processing, and products will be the dominant form for quite some time. Existing fossil-based plants with compatible equipment (e.g., hydrocrackers) will begin the externality-induced transition over to bio- and e-refinery formats to leverage this valuable existing infrastructure and logistical connections. Advanced separations play a role in this transition in several ways. First, advanced separations can partner with existing separation units (e.g., distillation) to extend the time in which fossil-based processing remains competitive under modern externalities (e.g., CO2).
Moreover, energy- and capital-efficient separation technologies can mitigate the decrease in returns of energy invested in fossil-based refining, due to greenhouse gas emission mandates. While bio- and e-refineries are often thought of as a greenfield for advanced separations technologies (thus bypassing the problem of working, amortized capital in existing plants), in fact, the adaptation of existing fossil-based refineries to renewable feedstocks suggests that the “hybrid” separation system paradigm is likely to be the standard for years to come. Nevertheless, these “green refineries” introduce many new separations challenges that are likely to be poorly addressed by conventional technologies. Finally, decades-old regulatory definitions of fuels will continue to promote distillation-centric refinery designs – flexibility in not only these regulations, but also in end use will pave the way for low energy, low carbon separation techniques. In this talk, comments on the future of the refining industry and the role of separations systems in the future will be discussed, in addition to specific research challenges facing membrane and adsorption technologies.

CEMB Future Leaders Seminar: "Enhanced matrix stress relaxation promotes cell migration"
2021-10-13 11:00 - 12:00 | https://upenn.zoom.us/j/96715197752
Launched in May 2021, the Future Leaders in Mechanobiology is a monthly seminar series featuring up-and-coming leaders in mechanobiology–PhD students and postdocs from a wide range of fields, backgrounds, and institutions. By providing an international stage to share one’s work and opportunities to interact with researchers at all career stages, we aim to create an inclusive and valuable series for early-stage researchers and the mechanobiology community as a whole.
Register HERE for access to the Zoom link and visit the CEMB website for more information.

CIS Seminar:"David V.S. Goliath: the Art of Leaderboarding in the Era of Extreme-Scale Neural Models"
2021-10-12 15:30 - 16:30 | PA
Scale appears to be the winning recipe in today’s leaderboards. And yet, extreme-scale neural models are still brittle to make errors that are often nonsensical and even counterintuitive. In this talk, I will argue for the importance of knowledge, especially commonsense knowledge, and demonstrate how smaller models developed in academia can still have an edge over larger industry-scale models, if powered with knowledge.
First, I will introduce “symbolic knowledge distillation”, a new framework to distill larger neural language models into smaller commonsense models, which leads to a machine-authored KB that wins, for the first time, over a human-authored KB in all criteria: scale, accuracy, and diversity. Next, I will introduce a new conceptual framework for language-based commonsense moral reasoning, and discuss how we can teach neural language models about complex social norms and human values, so that the machine can reason that “helping a friend” is generally a good thing to do, but “helping a friend spread fake news” is not. Finally, I will discuss an approach to multimodal script knowledge, which leads to new SOTA performances on a dozen leaderboards that require grounded, temporal, and causal commonsense reasoning.

Tedori-Callinan Lecture: "Resist Fatigue by De-concentrating Stress"
2021-10-12 10:00 - 11:30 | Zoom – Email MEAM for Link, peterlit@seas.upenn.edu
Most materials suffer from a disease: fatigue. Symptoms include degradation of properties and growth of cracks under cyclic stretch. These materials are unfit for applications involving prolonged and cyclic loads. A crack grows in a material because the crack tip concentrates stress. Recently, we have been developing fatigue-resistant materials by de-concentrating stress, through mechanisms at either microstructural or molecular scale. This talk describes the mechanics and implementations in materials.

POSTPONED: PSOC@Penn Seminar: Morgan Huse
2021-10-11 12:00 - 13:00 | Raisler Lounge (Room 225), Towne Building, 220 South 33rd Street, Philadelphia, PA, 19104, United States

GRASP on Robotics: "Motion Planning for Autonomy: Successes and Challenges Ahead"
2021-10-08 10:30 - 11:45 | Wu and Chen Auditorium (Room 101), Levine Hall, 3330 Walnut Street, Philadelphia, PA, 19104, United States
The past two decades have witnessed incredible advances towards the design of autonomous systems. This talk will discuss the role of motion planning in yielding solutions for an agent that is able to execute a variety of tasks in a variety of settings. Problem decomposition has been and remains a difficult task, and motion planning algorithms are today exploited for this purpose. Another critical step is to produce motion from high-level specifications. The specifications declare what the robot must do, rather than how the task is to be done. In that realm, motion planning principles guide the development of new frameworks that integrate advances in logical reasoning and program synthesis. The talk will discuss the work of my group in the above areas.
Join Zoom Webinar Here

MSE Seminar: "Metals and Alloys: A Critical Weapon in the Fight against Climate Change"
2021-10-07 12:15 - 13:30 | Auditorium, LRSM Building, 3231 Walnut Street, Philadelphia, PA, 19104, United States
Today in the U.S., we deal with the severe, wide ranging effects of climate change from the West to East Coast in the form of heat waves, drought, wildfires, and flooding. To end these disasters, we need to drastically change the way we produce and use energy. For example, in 2020, over 72 % of the energy consumed in the U.S. came from burning natural gases (31.5 %), coal (9.21 %) and petroleum (32.2 %), [1] which are all major contributors to U.S. carbon pollution. Experts agree that we need to move away from fossil fuels and embrace renewable energy technologies. At present, some of our most sophisticated renewable energy efforts involve the transition from coal and gasoline to Li-ion battery and hydrogen energy technologies. A fundamental problem with these solutions is the extremely low volumetric energy density of Li-ion batteries (blue marker in Fig. 1) and hydrogen fuel (red marker in Fig. 1) compared to coal and gasoline (grey markers in Fig. 1). [2] In addition, Li-ion battery technology suffers from several drawbacks, which Dr. Detsi will discuss in this talk, alongside with the efforts of his group to mitigate these issues, including the highly inefficient roll-to-roll battery manufacturing process and the poor cycle life of Li-ion batteries caused by a gradual degradation of electrode materials during (dis)charging. [3-5] Similarly, the use of hydrogen as a fuel is hampered by the low scalability of sustainable hydrogen production methods, the high costs and safety issues associated with hydrogen storage, and the lack of hydrogen infrastructures nationwide. Thus, hydrogen and metal-ion (such as Li-, Na-, K-, and Mg-ion) battery technologies are obviously not suitable for grid scale and heavy-duty energy applications.
An alternative approach involves reversibly storing renewable energy in Earth-abundant metals (such as Al, Mg, and Fe) or metalloids (B, Si). These materials exhibit much higher volumetric energy densities than coal and gasoline, as shown by the green markers in Fig. 1. [2] Typically, Fig. 1 reveals us that, for a given fixed volume fuel, burning Fe metal as a fuel will release twice as much energy as burning coal or gasoline; and burning Al metal will release three times as much energy as burning coal or gasoline.[2] By activating these metals through nanostructuring, these materials can release energy through reaction with oxygen (i.e. dry metal fuel oxidation) or water (i.e. wet metal fuel oxidation). In this talk, Dr. Detsi will discuss how we activate reactive metals like Al, Mg, and Zn using dealloying, and use these metals to release energy in the form of heat and chemical bonds (hydrogen) through hydrolysis (i.e. wet metal fuel oxidation).[6-8] After energy is extracted through oxidation, the solid reaction products in the form of metal (hydr)oxides can then be converted back into pure metals through reduction using sustainable energy resources such as hydropower, solar power and wind power to enable a sustainable metal fuel economy.[2] In this talk, he will also discuss the effort in his group to convert Al (hydr)oxide into metallic Al.[9]

CBE Seminar: "Electrolytes for High Energy Li-ion and Li Metal Batteries"
2021-10-06 15:30 - 16:30 | Wu and Chen Auditorium (Room 101), Levine Hall, 3330 Walnut Street, Philadelphia, PA, 19104, United States
Abstract
Electrolytes are critical enabling components for Li-ion batteries to safely operate within a wide temperature range, under extreme fast charging, and under intense abuse conditions without sacrificing energy density and cycle life. Current electrolytes cannot satisfy these requirements. We developed advanced all-fluorinated electrolytes, water-in-sale (WIS) electrolytes and solid-state electrolytes aiming to simultaneously enhance cell energy density and safety. Guided by the electrolyte design principle for high-capacity electrodes with large volume changes, we developed serval organic liquid electrolytes suitable for micro-sized Si and Li metal anodes and NMC cathodes. We also reduced the salt concentration of water-in-salt electrolytes from 21m to 4.5m, and extended the electrochemical stability window from 3.0V of WIS to 3.4V. These improved electrolytes enable LiMn2O4/Li4Ti5O12 pouch cells with an areal capacity of 2.5 mAh/cm2 and a P/N capacity ratio of 1.14 to achieve a long cycle life of 500. For solid state electrolyte Li metal batteries, we suppressed the Li dendrite growth and reduced the interface resistance by constructing a lithionphobic-lithiophoilic interlayer between solid electrolyte and Li metal anodes. The critical role of solid electrolyte interphase in accommodating electrode volume changes was also investigated.

PICS Student Seminar: "Keshav Patil and Yansong Gao"
2021-10-06 12:00 - 13:00 | Zoom – email kathom@seas.upenn.edu
Yansong Gao Title: “A Free-Energy Principle for Representation Learning”
Keshav Patil Title: “Altered protein dynamics delineates the oncogenic potential of various kinase mutations”
On Wednesday, October 6 at 12:00, PICS will host a virtual student seminar featuring Yansong Gao, a 4th year PhD in the Chaudhari group; and Keshav Patil, 4th year PhD in the Radhakrishnan group. At this seminar each student will present for 30 minutes and then take questions.

ESE Fall Colloquium Seminar - "Toward Practical Quantum Advantage: Many-body Physics in the NISQ Era"
2021-10-06 11:30 - 12:30 | Raisler Lounge (Room 225), Towne Building, 220 South 33rd Street, Philadelphia, PA, 19104, United States
Quantum processors of today are already capable of surpassing classical supercomputers on certain specialized tasks [1]. A current milestone for the quantum information science community is the fulfilment of quantum computational advantage on a practical problem of interest. The beginning of this talk will outline our technical progress on realizing various high-fidelity quantum gates on Google’s Sycamore processor, such as iSWAP and CPHASE. We then focus on two experiments studying many-body phenomena that have previously proven elusive on all quantum computing or simulation platforms: discrete time-crystals (DTC) and quantum scrambling.
In the DTC work, we implement Floquet dynamics on a 1D chain of 20 superconducting qubits [2]. Engineered disorders in the two-qubit couplings allow many-body localization (MBL) to occur despite strong external drive, thereby stabilizing a non-equilibrium phase of matter [3]. We carefully validate the phase structure of the DTC by probing the average response of all eigenstates belonging to the Floquet unitary. Using a suitable choice of order parameter, we further identify the location of the MBL-ergodicity crossover via experimentally observed finite-size effects. These results open a direct path to studying quantum phase transitions and critical phenomena on NISQ quantum processors. In the quantum scrambling work [4], we deploy a full 2D grid of 53 qubits and implement quantum circuits with tunable complexity. By measuring the quantum fluctuation of out-of-time-ordered correlators (OTOCs), we resolve the two key requisites of quantum scrambling: operator spreading and operator entanglement. Results from the most complex quantum circuits require ~100 hours to simulate on a CPU core via best-known classical algorithms, indicating the potential for achieving practical quantum advantage in the near term.
[1] Google AI Quantum and Collaborators, Nature 574, 505 (2019).
[2] X. Mi, M. Ippoliti, K. Kechedzhi, V. Khemani, P. Roushan et al., arXiv:2107.13571 (2021).
[3] M. Ippoliti, K. Kechedzhi, R. Moessner, S. Shivaji, V. Khemani, PRX Quantum (In press).
[4] X. Mi, P. Roushan, C. Quintana, K. Kechedzhi, V. Smelyanskiy, Y. Chen et al., arXiv:2101.08870 (2021).

MEAM PhD Thesis Defense: "Analytical Homogenization Estimates for the Effective Properties and Field Statistics of Viscoplastic Composites and Particle Suspensions"
2021-10-05 13:00 - 14:00 | Zoom – Email MEAM for Link, peterlit@seas.upenn.edu
Heterogeneous materials are commonly found in nature (e.g. soil, rock, blood) and engineering applications (e.g. paints, lubricants, sintered materials). Understanding the microstructure-properties relations is crucial to predicting how these materials fail and behave during processing.
In this thesis, we develop semi-analytical homogenization estimates for the macroscopic properties and field statistics of viscoplastic composites. A generalization of classical homogenization estimates for anisotropic linear two-phase composites is proposed. The generalized estimates are consistent with known bounds for the effective properties and satisfy certain duality properties relating the primal and dual formulations of the homogenization problem. Particularly for composites with large phase contrast, the new estimates are expected to have improved predictive capabilities as they can capture — at least qualitatively — the onset of clustering of the inclusion phase at non-dilute volume fractions. The new estimates also have important implications for the phase averages of the stress and strain-rate fields as well as the field fluctuations. In addition, for the special case of monodisperse suspensions of rigid spheres in a Newtonian fluid, the new estimates for the shear viscosity are validated against experimental results.
The generalized estimates are then used to estimate the effective behavior of nonlinear viscoplastic composites. To that end, we employ the variational linear comparison methods, which make use of optimally chosen linear comparison composite media, allowing the direct conversion of estimates for linear composites into corresponding estimates for nonlinear composites. For suspensions of rigid spheres in a Herschel-Bulkley fluid, the estimates for the effective yield and flow stress are validated against experimental results. Second-order linear comparison homogenization estimates for nonlinear viscoplastic composites with infinite phase contrast are generated and the dependence of the effective behavior on the macroscopic loading conditions is investigated. Special attention is devoted to the method’s ability to capture the highly localized anisotropic deformation patterns that emerge in composites with a finite yield stress. Under pure shear loading conditions the dependence of the effective yield stress is found to be non-analytic for dilute inclusion volume fractions which is shown to be connected to the emergence of shear bands.

MEAM Seminar: "Electrets, Magnetics and Deformation in Soft Materials"
2021-10-05 10:00 - 11:30 | Zoom – Email MEAM for Link, peterlit@seas.upenn.edu
Soft robotics, energy harvesting, large-deformation sensing and actuation, are just some of the applications that can be enabled by soft dielectrics that demonstrate substantive electromechanical coupling. Imagine now also a material that will produce electricity and deform substantively via a contactless, wireless magnetic signal. Unfortunately, truly soft, naturally occurring piezoelectric or magnetoelectric materials essentially do not exist. In this presentation, I will illustrate how mechanics and the concept of electrets i.e. materials with immobile embedded charges and dipoles, may be used for the design of soft piezoelectric, magnetoelectric, and electrocaloric materials. I will also briefly discuss the ramifications our results to explain biophysical phenomena such as the infrared vision of snakes or the ability of some animals to detect magnetic fields.

PSOC@Penn: "Microtubule Deacetylation Enables in vivo Collective Cell Migration by Tuning Cell Stiffness in Relation to Substrate Stiffness" (Abdul N. Malmi-Kakkada)
2021-10-04 12:00 - 13:00 | Raisler Lounge (Room 225), Towne Building, 220 South 33rd Street, Philadelphia, PA, 19104, United States
