Penn Engineering Events

MEAM Ph.D. Thesis Defense: "Coupling Hard and Soft Interfaces to Realize Actuators and Energy Sources that Bring Robots Towards Animal Mobility"
2024-11-11 13:00 - 14:00 (America/New_York) | Raisler Lounge (Room 225), Towne Building, 220 South 33rd Street, Philadelphia, PA, 19104, United States
Mobile robots have shown significant advancements in agility, intelligence, and efficiency over the past few decades. However, their endurance and overall performance remain limited by the onboard power supplies. Current power sources typically restrict mobile robots to areas close to the electrical grid and necessitate heavier batteries for extended range. Energy refueling could be significantly challenging in remote and inaccessible regions, and traditional energy harvesting methods have also proven inadequate for sustaining continuous operations.
To address this challenge, we propose a bio-inspired approach: enabling robots to “digest” energy-dense metals for power generation, analogous to how animals process food for energy. This concept builds upon aluminum-air batteries, which operate as miniature chemical plants converting aluminum into electricity. We selected this technology for three key advantages: (1) exceptional energy density for improved endurance compared to conventional lithium batteries; (2) simple anode replacement for rapid refueling without charging stations; and (3) readily available fuel sources from everyday aluminum materials, from beverage cans to construction waste.
This thesis investigates how aluminum-air batteries can benefit the robotics community through four interconnected studies. First, we quantify the energy gap between mobile robots and their biological counterparts through comparative analysis of energy and power density, establishing benchmarks for future battery technologies to achieve biological equivalence. Second, we demonstrate the development of a highly stretchable metal-air battery using sliding electrodes, achieving up to 10-fold improvements in areal capacity and power compared to existing stretchable designs, which could extend the endurance and unleash the potential of various soft robots and wearable technologies. Third, we implement customized metal-air batteries on an Arduino-based robot platform, demonstrating continuous operation through metal oxidation using various aluminum and zinc sources while addressing challenges such as byproduct accumulation, hydrogen production, and water consumption. Finally, we showcase a feasible approach to develop a soft crawler based on this metallivore concept, capable of simultaneous metal digestion and continuous locomotion. By developing this aluminum-air battery-based energy solution, we demonstrate a path toward extending robots’ operational range and endurance beyond current limitations, thereby expanding their potential in remote and complex environments.

Tedori-Callinan Distinguished Lecture: "Novel Passive and Active Approaches to Fluid Friction Reduction using Polymers & Plastrons"
2024-11-12 10:15 - 11:15 | Wu and Chen Auditorium (Room 101), Levine Hall, 3330 Walnut Street, Philadelphia, PA, 19104, United States
When a superhydrophobic (SH) textured surface is immersed in water it traps a thin shiny layer of air within the texture that is known as a plastron. Contact line pinning stabilizes this Cassie-Baxter state and the patches of air trapped in the texture can act as shear-free regions that locally lower the frictional dissipation. Recent developments of scalable manufacturing methods for producing robust SH surfaces open new possibilities for using these textures in drag reduction applications. We use a newly-developed bespoke Taylor-Couette (TC) apparatus to compare and contrast frictional drag reduction by dilute polymer solutions and superhydrophobic (SH) surfaces in turbulent flows for Reynolds numbers over a wide range (10,000 < Re < 100,000). By applying SH coatings to the inner rotating cylinder, we can evaluate the drag reducing performance and robustness of different textures and calculate the effective slip length in turbulent flow using a suitably augmented Prandtl-von Kármán (PvK) analysis. We also investigate how these plastrons can be partially stabilized against turbulent pressure fluctuations using active heating as well as chemical methods to locally regenerate vapor. Additionally, we can use our apparatus to revisit an alternative drag-reducing strategy using dilute solutions of various high molecular weight polymers. We show that natural polysaccharides derived from plant mucilage can be an inexpensive and effective alternative to costly synthetic polymers, whilst still approaching the same maximum drag reduction (MDR) asymptote. Finally, we explore combinations of these two complementary drag reduction methods – one arising from wall slip and the other due to changes in turbulence dynamics in the bulk flow – and find that the two effects are not always additive; interestingly, the effectiveness of polymer drag reduction can actually be reduced in the presence of a SH coating on the wall.

ESE Fall Seminar - "Color center photonics in silicon carbide: scalable fabrication, cryogenic experiments, and quantum simulation on NISQ testbeds"
2024-11-12 11:00 - 12:00 | Raisler Lounge (Room 225), Towne Building, 220 South 33rd Street, Philadelphia, PA, 19104, United States
Color center systems are among the leading platforms in the development of quantum communication and quantum sensing hardware due to their desirable spin, optical, and spin-photon properties. Among them, the near infrared emitters in silicon carbide, such as the nitrogen-vacancy center in 4H-SiC, provide fiber-friendly operation in an industrially mature substrate, ideal for scalable deployment of quantum networking hardware. By exploring the triangular geometry in quantum-grade SiC, we develop the first wafer-scale fabrication process for color center photonics based on ion beam etching at an angle, realizing a broad range of devices for guiding and resonating light.
Due to their near-identical emission, color centers enable unprecedented studies of multi-emitter-cavity physics, or the Tavis-Cummings (TC) model, with applications in quantum light generation and quantum memories. Here, a lossy resonator interacts with multiple quantum emitters in resonant and off-resonant systems. Modeling of TC systems in an open quantum setting is limited to small dimensions on classical computing resources. We explore how quantum computers can help bridge this knowledge gap and propose algorithms for quantum mapping, analog and digital simulation of the TC model on superconducting and trapped ion DOE testbeds.

MEAM Ph.D. Thesis Defense: "Impulse-Induced Nonlinear Dynamics of Flexible Mechanical Metamaterials"
2024-11-13 10:00 - 11:00 | Room 2C2, David Rittenhouse Laboratory Building, 209 S. 33rd Street, Philadelphia, PA, 19104, United States
Mechanical metamaterials are artificially designed structures that exhibit unique properties due to their internal structure rather than their composition, e.g., negative Poisson’s ratio, tunable stiffness, and advanced thermal characteristics. While the static properties of mechanical metamaterials have been widely studied, their nonlinear dynamics remain largely unexplored, which could pave ways for innovative design and optimization for novel applications related to deployable structures, reconfigurable robots, and more. This dissertation aims to expand the fundamental understanding of flexible mechanical metamaterials through the combination of analytical, numerical, and experimental methods. This thesis is divided into three areas: the triggering of phase transitions through the collision of vector solitons in a multistable structure comprising rotating squares, the exploration of asymptotic energy propagation in a flexible Kagome lattices, and the development of a bio-inspired pulse-driven flexible platform for rapid motion control of underactuated systems. These studies demonstrate that mechanical metamaterials possess rich nonlinear dynamical behaviors, including soliton collisions leading to phase transitions, the preservation and disruption of topological modes under nonlinear loading, and spatiotemporal dynamics that can be applied toward stabilization of robots subjected to sudden loads.

ESE Fall Seminar - "Algorithmic Bias in Computer Vision - Generative Methods Enable the Experimental Approach"
2024-11-13 10:30 - 11:30 | Wu & Chen Auditorium
As Artificial Intelligence (AI) finds increasing applications in industry and society. Responsible deployment demands that we measure and correct algorithmic biases vis-a-vis protected attributes such as sex, age and ethnicity. State of the art methods for measuring algorithmic bias rely on test sets that are collected in the wild and are then annotated for the protected attributes. Such methods are therefore observational and yield correlational information. I will argue that in order to obtain useful information to discover and correct biases we need causal information which is only available if we use an experimental method. I will show that modern generative models offer a promising starting point to develop experimental testing methods. I will review our recent work in face synthesis and demonstrate its application to the study of algorithmic bias in gender classification, face recognition, and social judgment of faces.

ASSET Seminar: "Multi-Omic Approaches for Deciphering Cellular Heterogeneity and Plasticity in Cancer"
2024-11-13 12:00 - 13:15 | Raisler Lounge (Room 225), Towne Building, 220 South 33rd Street, Philadelphia, PA, 19104, United States
Abstract:
Tumors are complex and heterogeneous systems, which challenge their classification and treatment. The Silverbush lab decodes tumor heterogeneity and plasticity to understand how cancer cells transform to become more aggressive or evade treatment. We particularly examine hard-to-treat cancers with high heterogeneity, focusing on the notorious kings of heterogeneity and aggressiveness: brain cancers. To achieve this goal, we develop computational multi-omic single-cell tools. These tools enable us, for the first time, to simultaneously measure DNA methylation, point mutations, and transcriptional activity in the same single cells. We then use these tools to study patient samples, often treated with innovative clinical trials, and build solutions to understand whom the treatment can help, how to improve it, and what the optimal time window is for administering it.
Zoom Link (if unable to attend in-person): https://upenn.zoom.us/j/96390831586

Introduction to COMSOL Multiphysics® Workshop
2024-11-13 14:00 - 15:30 | PICS Conference Room 534 – A Wing , 5th Floor, 3401 Walnut Street, Philadelphia, PA, 19104, United States
We are excited to announce that COMSOL will be coming to the University of Pennsylvania for a free special event. On November 13th at 2pm we will be providing a Introduction to COMSOL Multiphysics® Workshop on campus at 3401 Walnut Street Wing A, Conference Room 534, 5th Floor.

At this workshop, you will see the capabilities and workflow of the COMSOL Multiphysics® software and learn through a guided hands-on exercise. You will leave with some new skills to work on your own applications using a free two-week COMSOL Multiphysics trial.

We are excited to meet with you and discuss your simulation interests. Please bring along all of your questions and any interested colleagues!

You can register and find more details on the event at the page below:
https://www.comsol.com/events/workshop/introduction-to-comsol-multiphysics-workshop-for-upenn-123252

Fall 2024 GRASP SFI: Noémie Jaquier, Karlsruhe Institute of Technology, “The geometric side(s) of Lagrangian dynamics”
2024-11-13 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 on Zoom. This week’s speaker will be virtual.
ABSTRACT
Lagrangian mechanics provides a powerful framework for modeling the dynamics of physical systems by inferring their motions based on energy conservation. This talk will explore recent advances in applying geometric perspectives, particularly Riemannian geometry, to Lagrangian principles for predicting and optimizing motion dynamics. First, I will discuss how the dynamic properties of humans and robots are straightforwardly accounted for by considering geometric configuration spaces. Second, I will show how this geometric approach can be extended to generate dynamic-aware, collision-free robot motions by modifying the underlying Riemannian metric. Finally, I will consider the problem of learning unknown high-dimensional Lagrangian dynamics. I will present a geometric architecture to learn physically-consistent and interpretable reduced-order dynamic parameters that accurately capture the behavior of the original system.

ESE Guest Seminar - "Coherent Control of Electromagnetic Waves via Tunable Chaotic Cavities"
2024-11-14 10:30 - 11:30 | Towne 337
The theory of Coherent Perfect Absorption1 (time-reversed lasing) and Reﬂectionless Scattering Modes2 has shown that there always exist discrete solutions to scattering of electromagnetic waves in multiple-scattering geometries that achieve perfect transduction or perfect (reﬂectionless) impedance matching. In general these are transient (complex frequency) solutions, but, typically, with tuning of a one system parameter it is possible to achieve steady- state, reﬂectionless excitation of arbitrary systems. Here we focus on the case of reﬂectionless excitation of a lossless multiport/multi-channel system, and show3 that it is possible not only to eliminate reﬂection, but also to control the scattering into the output channels to perform routing or ﬁltering functions. This is achieved by creating a degeneracy of d complex eigenvalues of the wave equation, tuned to the real frequency; and we ﬁnd that the number of tuning parameters needed to achieve such routing at a given frequency to be 2(d+1). For heuristic reasons we expect an open low-loss wave-chaotic cavity with tunable scattering elements to be optimal for achieving routing functions, since such a cavity has overlapping, pseudo-random resonances, making it frequency agnostic, and easily reprogrammable. We will present the results of recent experiments4 and simulations3,4 of such a cavity that have conﬁrmed this conjecture in the microwave frequency range. These systems are easily reprogrammable, making them uniquely eﬀective for applications where frequency- agile performance is required and implying robustness to perturbations and defects in fabrication.

“Coherent Perfect Absorbers: Time-reversed Lasers”, D. Chong, L. Ge, H. Cao, and A. D. Stone, Physical Review Letters, 105, 053901 (2010).
“Theory of Reﬂectionless Scattering Modes”, William Sweeney, Chia Wei Hsu, and A. Douglas Stone, Phys. Rev. A, 2020, https://link.aps.org/doi/10.1103/PhysRevA.102.063511
“Coherent Control of Scattering of Guided Waves”, in preparation, A. Alhulaymi, Pyvovar, P. Del Hougne, O. D. Miller, A. D. Stone.
“Agile Free-Form Signal Filtering with a Chaotic-Cavity-Backed Non-Local Programmable Metasurface”, T. Faul, L. Cronier, A. Alhulaymi, A. D. Stone, P. del Hougne, submitted to Advanced Materials.

MSE Seminar: "Luminescent Photonic Metamaterials and Devices From THz to Optical Frequencies"
2024-11-14 10:30 - 12:00 | Wu and Chen Auditorium (Room 101), Levine Hall, 3330 Walnut Street, Philadelphia, PA, 19104, United States
A crucial yet unavailable component in high-performance photonic integrated circuits (ICs) and other chip-scale photonic systems is an on-chip light source that is efficient, functional, IC-compatible, and electronically addressable. In this talk, I will cover several types of on-chip sources, including perovskite microlasers and luminescent hyperbolic metamaterials, topologically protected microlasers on the III-V platform, as well as spintronic THz emitters on the III-N platform.

Fall 2024 GRASP Seminar: James Bern, Williams College, "Mixed Reality Soft Robots and Accessible CAD Software"
2024-11-14 11:00 - 12:00 | Levine 307, 3330 Walnut Street, Philadelphia, PA, 19104, United States
*This seminar will be held in-person in Levine 307 as well as virtually via Zoom. This seminar will NOT be recorded.
ABSTRACT
This talk has two parts. First, I will explain our recent work on making it easier to control 3D soft robots. By extending our prior work on soft robot inverse kinematics (Soft IK) into virtual reality (VR), we realize an intuitive, real-time posing pipeline for arbitrary 3D soft robots. This pipeline promises to extend to mixed reality applications. Second, I will introduce a new experimental CAD program called Conversation. Conversation enables novice users to quickly design simple 3D-printed machines. The software features a unique workflow (2D sketch and 3D part remain separate), utilizes an unconventional mesh-based geometry kernel (Manifold), and is very fast (go from DXF to STL in seconds – minutes) and very small (executable weighs ~1 MB). It is also a promising target for new computational design algorithms.

Research + Innovation Seminar Series - Sponsored Research
2024-11-14 12:00 - 13:00 | Raisler Lounge (Room 225), Towne Building, 220 South 33rd Street, Philadelphia, PA, 19104, United States

Fall 2024 GRASP on Robotics: Damion Shelton, Agility Robotics, “What do we want from our machines?”
2024-11-15 10:30 - 11:45 | Wu and Chen Auditorium (Room 101), Levine Hall, 3330 Walnut Street, Philadelphia, PA, 19104, United States
This will be a hybrid event with in-person attendance in Wu and Chen and virtual attendance on Zoom.
ABSTRACT
In 2022 I represented Agility Robotics at the first “Philadelphia Summit” on the weaponization of autonomous robots, co-hosted by the GRASP lab and Boston Dynamics. By late fall, this yielded a joint statement, signed by Agility, Boston Dynamics, and others, with the self-explanatory title “General Purpose Robots Should Not Be Weaponized”. But why general purpose robots? And why now? After that summit, a follow-up conference, “Ethical and Legal Dilemmas of Autonomous Weapons in War and National Security”, was hosted by CERL in 2024, against the backdrop of the Ukraine war and growing public awareness of the role of drones and other semi-autonomous weapons systems. While this event has not (yet) yielded a specific industry response, it further refines the concept of perceived harm from 2022 by adding the explicit call-out that the ethical and legal dilemmas of mobile robots are inseparably tied to autonomy. Further, virtually the entirety of modern generative AI awareness, including among industry experts, has come to pass since the original 2022 event.
The purpose of this talk is twofold. First, humanoid robots – since they look like us, occupy our spaces, and are able to perform tasks in a manner similar to us – are the ultimate instantiation of “general purpose” robots. What are the ethical, legal, and social implications of this sort of technology? Are robots like Digit actually different from a pick and place machine, or a Roomba? And second, does this situation change when you add advanced AI?
Over and above the focus of the 2022 and 2024 summits, this talk will evaluate a broader set of axes than just robots as weapons. Since we are still in the early days of both modern AI and commercialized humanoid robots, we have the opportunity to ask a more general question: “What do we want from our machines?”

ESE 2024 Jack Keil Wolf Lecture - "Army of Ants: The Power of Working in Concert"
2024-11-15 16:00 - 17:15 | Glandt Forum, Singh Center for Nanotechnology, 3205 Walnut Street, Philadelphia, PA, 19104, United States
Synchronized operation of a large number of similar entities can generate behavior that cannot be expected from single one. This principle combined with the physical concept of coherence in waves enables creation of programmable 3-dimensional focal points that can be used to enable many applications such as wireless energy transfer at distance on earth and even from space, flat lensless projectors and cameras, and various other present and future applications. It can manifest itself in the form of phased arrays and focusing arrays with an ensemble of synchronized wave generating or receiving elements. While the individual element behavior may be rather unremarkable, such systems can lead to rich and useful behaviors. We will go through a journey based on this principle and a progression of its potential applications in an increasing order of outlandishness.

Fall 2024 GRASP Seminar: Yunzhu Li, Columbia University, “Foundation Models for Robotic Manipulation: Opportunities and Challenges”
2024-11-18 11:00 - 12:00 | Levine 307, 3330 Walnut Street, Philadelphia, PA, 19104, United States
*This seminar will be held in-person in Levine 307 as well as virtually via Zoom.
ABSTRACT
Foundation models, such as GPT-4 Vision, have marked significant achievements in the fields of natural language and vision, demonstrating exceptional abilities to adapt to new tasks and scenarios. However, physical interaction—such as cooking, cleaning, or caregiving—remains a frontier where foundation models and robotic systems have yet to achieve the desired level of adaptability and generalization. In this talk, I will discuss the opportunities for incorporating foundation models into classic robotic pipelines to endow robots with capabilities beyond those achievable with traditional robotic tools. The talk will focus on three key improvements in (1) task specification, (2) low-level, and (3) high-level scene modeling. The central idea behind this research is to translate the commonsense knowledge embedded in foundation models into structural priors that can be integrated into robot learning systems. This approach leverages the strengths of different modules (e.g., VLM for task interpretation and constrained optimization for motion planning), achieving the best of both worlds. I will demonstrate how such integration enables robots to interpret instructions provided in free-form natural language, and how foundation models can be augmented with additional memory mechanisms, such as an action-conditioned scene graph, to handle a wide range of real-world manipulation tasks. Toward the end of the talk, I will discuss the limitations of the current foundation models, challenges that still lie ahead, and potential avenues to address these challenges.

ESE Ph.D. Thesis Defense: "Learning-based Model Predictive Control for Aerial Vehicles"
2024-11-18 14:00 | Levine 307, 3330 Walnut Street, Philadelphia, PA, 19104, United States
Learning-based model predictive control (MPC) is an increasingly prominent control paradigm in recent years. One primary approach in learning-based MPC is to leverage machine or deep learning tools to construct accurate dynamics models. These models are then deployed into optimization-based control schemes. Although these frameworks can potentially provide significant performance improvements, a number of key challenges need to be addressed before they can realize their full potential and prove reliable for real-world applications. In this defense, I highlight a set of frameworks that alleviate these challenges in a systematic and holistic manner.
The data-driven models within learning-based MPC frameworks aim to strike a balance between architectural complexity and expressiveness. However, many of these models either have elaborate architectures, or lack sufficient expressiveness to capture the intricate interactions and nonlinearities within the system dynamics. As the first contribution of this defense, I outline a novel learning-based MPC framework that addresses this balance. In particular, I show how an accurate and architecturally simple dynamics model can be constructed by combining prior knowledge of the system with a data-driven component. This combined model is lightweight, making it highly compatible with nonlinear MPC. Another challenge in learning-based MPC frameworks is that the dynamics models are typically learned offline. This implies that the models often fail to account for the dynamic uncertainties experienced by the system during deployment. Learning the models online is possible, but that typically requires substantial training data and computational resources. As the second contribution of this defense, I alleviate these shortcomings by developing an adaptive framework that boosts both sample and computational efficiency, along with dynamic uncertainty compensation in learning-based MPC. A third challenge of learning-based MPC frameworks, is that there are often little or no guarantees on the accuracy of the data-driven models. As the third contribution of this defense, I leverage recent uncertainty quantification techniques to extract uncertainty estimates for the model predictions, which are equipped with probabilistic guarantees. These estimates are shown to be not overly conservative and are incorporated within a robustification framework to enhance the robustness of the system.

MEAM Seminar: "Can Materials From the 1930’s Really Revolutionize Battery Manufacturing?"
2024-11-19 10:15 - 11:15 | Wu and Chen Auditorium (Room 101), Levine Hall, 3330 Walnut Street, Philadelphia, PA, 19104, United States
Fluorinated polymers offer a plethora of unique and sometimes perplexing properties. One of the most interesting is the ability for specific types of polytetrafluoroethylene (PTFE) to undergo room-temperature, sheer-induced, structural transformations leading “unwinding” of crystallites and the formation of nano-scale fibers. This process is commonly referred to as “fibrillation”. The material properties required for this deformation mechanism are so unique that no other polymer is known to exhibit this behavior. By utilizing and controlling this property, complex composites can be manufactured with polymer loadings of less than 1% weight. Recently, this methodology has been used to revolutionize both cathode and anode manufacturing for lithium-ion batteries. This talk will overview the fundamentals of fibrillation, show methods to characterize structures, and discuss unique applications for these materials.

ESE Fall Seminar - "Non-Parametric Analysis of Dynamical Systems: From Recurrent Sets to Generalized Lyapunov and Barrier Conditions"
2024-11-19 11:00 - 12:00 | Raisler Lounge (Room 225), Towne Building, 220 South 33rd Street, Philadelphia, PA, 19104, United States
This talk presents novel non-parametric methods for analyzing dynamical systems using solely trajectory data. Our critical insight is to replace the notion of invariance, a core concept in Lyapunov Theory, with the more relaxed condition of recurrence. Specifically, a set is τ-recurrent if every trajectory that starts within the set returns to it after at most τ seconds. We leverage this notion of recurrence to develop several analysis tools and algorithms to study dynamical systems. Firstly, we consider the problem of learning an inner approximation of the region of attraction (ROA) of an asymptotically stable equilibrium point using trajectory data. We show that a τ-recurrent set containing a stable equilibrium must be a subset of its ROA under mild assumptions and develop algorithms that compute inner approximations of the ROA using counter-examples of recurrence obtained by sampling finite-length trajectories. Secondly, we generalize Lyapunov and Barrier Function Methods to allow for non-monotonic evolution of the function values by only requiring sub-level sets to be τ-recurrent (instead of invariant). We provide conditions for stability and safety using τ-monotonic functions (functions whose value along trajectories monotonically increases or decreases after at most τ seconds) and develop a verification algorithm that leverages GPU parallel processing power to verify stability and safety using only trajectory information. We finalize by discussing future research directions and possible extensions for control.

CIS Seminar: " Just Infrastructures"
2024-11-19 15:30 - 16:30 | Wu and Chen Auditorium (Room 101), Levine Hall, 3330 Walnut Street, Philadelphia, PA, 19104, United States
Sociotechnical systems enable large-scale connection and the dissemination of timely, engaging information. However, these systems are shaped by complex, often invisible governance structures—comprising rules, roles, and relationships—that significantly influence how they operate. Gaining even a basic understanding of these governance structures is key to using them more effectively and deliberately. Yet, many of the millions who depend on these systems are unaware of the governance mechanisms at play or their own degree of autonomy within them. In this talk, I will present methods to uncover hidden governance structures, unveil the illusion of control, and emphasize the importance of amplifying silenced voices to reshape both governance and our relationship with technology and one another — the goal being to create Just Infrastructures.

CIS Seminar: "Just Infrastructures"
2024-11-19 15:30 - 16:30 | Wu & Chen Auditorium

ASSET Seminar: "Control with Coarse Measurements: Perception Contracts and Indistinguishable Sets"
2024-11-20 12:00 - 13:15 | Raisler Lounge (Room 225), Towne Building, 220 South 33rd Street, Philadelphia, PA, 19104, United States
Abstract:
Performance of control systems depend on the nature of available measurements. Perception of edges, keypoints, landmarks and other natural semantic features make certain coarse measurements available to control systems operating in complex environments. This talk explores two problems related to control and estimation with such coarse measurements. First, I will introduce perception contracts—an approach for analyzing visual control systems that rely on Deep Neural Networks for state estimation. A perception contract provides an over-approximation of a state estimator while guaranteeing closed-loop system invariants. These contracts can be automatically synthesized using data and model-based analysis and have been applied to automated landing and lane-keeping systems. The second part of the talk will focus on algorithms for computing indistinguishable sets—sets of states that cannot be distinguished based on available coarse measurements. These sets help define the limits of state estimation and localization. The talk will touch on formal verification, information spaces, and related open problems.
Zoom Link (if unable to attend in-person): https://upenn.zoom.us/j/91934138074

CIS Special Industry Colloquium: "Scaling Paradigms for Large Language Models"
2024-11-20 13:45 - 15:15 | Glandt Forum, Singh Center for Nanotechnology, 3205 Walnut Street, Philadelphia, PA, 19104, United States
In this talk I will tell you how scaling has been the engine of progress in AI for the past five years. In the first scaling paradigm, our field scaled large language models by training with more compute on more data. Such scaling led to the success of ChatGPT and other AI chat engines, which were surprisingly capable and general purpose. With the release of OpenAI o1, we are at the beginning of a new paradigm where we do not just scale training time compute, but we also scale test-time compute. These new models are trained via reinforcement learning on chain-of-thought reasoning, and by thinking harder for more-challenging tasks can solve even competition-level math and programming problems. I will conclude with a few remarks on how AI research culture has changed and where the field might go next.

For more information please contact: Mayur Naik (mhnaik@seas.upenn.edu)

GRASP Special Panel featuring the 2024 John Scott Award Recipients
2024-11-20 14:00 - 15:00
This is an in-person event only and is not open to the public. Event Registration and Penncards are required. A link to register for the event will be sent via email.
PANEL DISCUSSION
Please join us for a panel discussion featuring the 2024 John Scott Award Recipients, Dr. Takeo Kanade (CMU), Dr. Vijay Kumar (Penn), & Dr. Daniela Rus (MIT). This panel will be moderated by Dr. Daniel E. Koditschek, GRASP Faculty Member and Penn Engineering’s Alfred Fitler Moore Professor.

CBE Seminar: "Scalable Access to the Hidden Topologies of Biology" (Albert Keung, North Carolina State University)
2024-11-20 15:30 - 16:30 | Wu and Chen Auditorium (Room 101), Levine Hall, 3330 Walnut Street, Philadelphia, PA, 19104, United States
Abstract:
Biology is characterized by a diversity of phenotypes and functions that outpace the limited molecular diversity encoded in genomes. How this is achieved is a fundamental and enduring mystery of the cell. It is clear that networks defining how biological molecules interact can drive diverse and complex phenotypes, but the intermolecular interactions or edges of these networks are highly multidimensional and difficult to measure at scale. The predictive power of models depends not only on the identities of components and their edges, but on complex properties of those edges ranging from intermolecular specificities, quantitative binding affinities, rate constants for enzymatic reactions, the influence of post-translational modifications, cross-talk between components, and the spatiotemporal organization and dynamics of network components and activities. This talk will describe the development of scalable synthetic biology platforms to comprehensively map these edge properties of protein networks, applied to the human epigenome. We will also describe how these principles need to be considered and engineered in completely abiotic applications that leverage biomolecules; specifically, we will describe the engineering of extremely dense digital information storage and computing systems with DNA as the information medium. We will also touch on how these principles translate upward in spatial scale to biomedical applications in neurological disorders such as Angelman Syndrome and in the engineering of human cerebral organoid models of the developing brain.

Fall 2024 GRASP SFI: Gioele Zardini, Massachusetts Institute of Technology, “Compositional Design of Complex Systems: From Autonomy to Future Mobility”
2024-11-20 15:30 - 16:30 | Levine 307, 3330 Walnut Street, Philadelphia, PA, 19104, United States
This seminar will start at 3:30 PM instead of 3:00. This will be a hybrid event with in-person attendance in Levine 307 and virtual attendance on Zoom.
ABSTRACT
When designing complex systems, we need to consider multiple trade-offs at various abstraction levels and scales, and choices of single components need to be studied jointly. For instance, the design of future mobility solutions (e.g., autonomous vehicles, micromobility) and the design of the mobility systems they enable are closely coupled. Indeed, knowledge about the intended service of novel mobility solutions would impact their design and deployment process, while insights about their technological development could significantly affect transportation management policies. Optimally co-designing sociotechnical systems is a complex task for at least two reasons. On one hand, the co-design of interconnected systems (e.g., large networks of cyber-physical systems) involves the simultaneous choice of components arising from heterogeneous natures (e.g., hardware vs. software parts) and fields, while satisfying systemic constraints and accounting for multiple objectives. On the other hand, components are connected via collaborative and conflicting interactions between different stakeholders (e.g., within an intermodal mobility system). In this talk, I will present a framework to co-design complex systems, leveraging a monotone theory of co-design and tools from game theory. The framework will be instantiated in the task of designing future mobility systems, all the way from the policies that a city can design, to the autonomy of vehicles as part of an autonomous mobility-on-demand service. Through various case studies, I will show how the proposed approaches allow one to efficiently answer heterogeneous questions, unifying different modeling techniques and promoting interdisciplinarity, modularity, and compositionality. I will then discuss open challenges for compositional systems design optimization, and present my agenda to tackle them.

MEAM Ph.D. Thesis Defense: "Tribosintering of Metal Oxide Nanocrystals"
2024-11-21 09:00 - 10:00 | Glandt Forum, Singh Center for Nanotechnology, 3205 Walnut Street, Philadelphia, PA, 19104, United States
Machinery relies on lubrication to regulate friction and wear at contacting interfaces. As lubricants become less viscous to save energy and cost, and as new technologies like electric vehicles operate in harsher conditions, the risk of surface-initiated failure grows. We show that metal oxide nanocrystals (NCs) dispersed in lubricants form protective coatings, or tribofilms, in situ at contacting interfaces via tribosintering. Compared to state-of-the-art antiwear additives and surface coatings, metal oxide tribofilms have several advantages, but the lack of fundamental knowledge about the growth and wear processes of these tribofilms is a key factor hindering adoption of NCs in lubricants. We reveal mechanisms behind metal oxide tribofilm formation through macro-scale, application-relevant experiments.
We use a benchtop tribometer capable of commercially relevant conditions — the mini-traction machine (MTM) with spacer layer imaging (SLIM) — to refine experimental study of metal oxide tribofilm formation. First, we consider the nanocrystals as anti-wear additives, demonstrating that the SLIM technique captures and quantifies local wear events during tribofilm growth. The competition wear and growth can be tuned by, e.g., the addition of S- and P-based co-additives, which increase the initial rate of tribofilm growth while contributing to a more polished steady-state tribofilm morphology. We then use the nanocrystals to form in situ metal oxide surface coatings at low homologous temperatures in a variety of realistic conditions. We show that ZrO2, TiO2, and BaTiO3 all form durable, anti-scuffing coatings near room temperature, offering robust practical benefits. We then generalize an under-appreciated feature of SLIM, disaggregating tribofilm thickness measurements to correlate pixels of data with local contact stress and contact time in contact. Local tribofilm thickness variations at a given time are best explained by differences in exposure to interfacial sliding, not differing contact stresses — an unacknowledged driver of tribosintering. We then show that a property-dependent critical length scale explains the differing wear behavior of ZrO2 and TiO2 tribofilms, providing a physically motivated design criterion for application. Finally, we discuss data-driven efforts to model tribofilm formation, demonstration unique benefits including correction of corrupted data, and a process to iteratively test analytical models.

THIS EVENT HAS BEEN CANCELLED: ESE Fall Seminar - "A changing grid powered by the new generations of power conversion, control, and energy management"
2024-11-21 10:30 - 11:30 | Towne 337
The electric grid is undergoing a transformative paradigm shift, driven by sweeping changes in generation, demand, and energy storage. By 2035, solar PV alone is expected to supply 40% of U.S. electricity, with substantial additional contributions from wind, geothermal, and hydroelectric sources—creating a renewable-dominant energy landscape. Meanwhile, electricity demand is accelerating due to rapid growth in electric vehicle (EV) charging, data centers, industrial manufacturing, and universal electrification across sectors. By 2050, EV charging is anticipated to represent 23% of the nation’s electricity demand. Energy storage system installations are also expanding to manage the variability of renewable sources, support dynamic loads, and ensure grid stability.
This seminar will discuss the pivotal role of high power, high voltage, and high frequency power converters in creating a flexible, efficient, and resilient grid. We will examine integration challenges for 15kV-class converters within the AC grid, as well as the opportunities these converters present for real-time voltage stabilization, frequency regulation, and dynamic grid management. High-bandwidth converters are key enablers of a smart, adaptable grid, facilitating higher renewable penetration, dynamic load management, and enhanced compatibility with energy storage. A few projects on grid-connected power electronics will highlight how these advancements can drive the evolution of a robust and versatile grid architecture to meet the demands of a power electronics-driven energy future.

MSE Seminar: "Nano to Mesoscale: Structure, Composition, and Transport Processes in Human Dental Enamel"
2024-11-21 10:30 - 12:00 | Wu and Chen Auditorium (Room 101), Levine Hall, 3330 Walnut Street, Philadelphia, PA, 19104, United States
Mineralized tissues are paradigmatic hierarchical materials that reap synergy from structural and compositional gradients at multiple length scales in ways that are challenging to reproduce by conventional means. My laboratory studies the formation, functional properties, and degradation of mineralized tissues. We use model systems ranging from single crystalline endoskeletal elements deposited by single cells to the formation of dental tissues that comprise nanocrystalline and amorphous minerals deposited in complex organic matrices. Applications include the development of bio-inspired materials, sequestration of 90 Sr from nuclear waste, and improving prophylaxis and minimally invasive intervention in dental care.
Herein, I will focus on dental tissues that are optimized to withstand the forces of mastication and the challenging chemical environment of the oral cavity. Human dental enamel is composed of hydroxylapatite (Ca 5 (PO 4 ) 3 OH) nanocrystallites, thousands of which are bundled into rods that are organized in a three-dimensional weave; this provides great fracture resistance and a much-enhanced fatigue life but leaves our teeth vulnerable to erosive tooth wear and tooth decay (caries). I will discuss how chemical imaging using UV-laser pulsed atom probe tomography (APT), electron microscopy, and synchrotron X-ray techniques has provided deep new insights into the chemistry of nanoscale organic/inorganic interfaces, presence of amorphous intergranular phases, and complex dopant gradients that are integral to properties of teeth and their resistance to corrosion.[1-5] I will further report on development of correlative elemental imaging using X-ray diffraction at the mesoscale (here: 0.25-20 µm) that allows us to extend the field of view beyond what APT can deliver.[6] Finally, I will provide an update on our investigation of diffusive transport processes in enamel using APT and ToF-SIMS, and discuss my vision for integrating this information to enable predictive modeling of enamel dissolution.
[1] Gordon and Joester, Nature 2011, 469, 194-197. [2] Gordon, Tran, and Joester, ACS nano 2012, 6, 10667-10675. [3] Gordon, Cohen, MacRenaris, Pasteris, Seda, and Joester, Science 2015, 347, 746-750. [4] Gordon, Joester, Front Physiol 2015, 6. [5] DeRocher, Smeets, Goodge, Zachman, Balachandran, Stegbauer, Cohen, Gordon, Rondinelli, Kourkoutis, Joester, D. Nature 2020, 583, 66-71. [6] Free, DeRocher, Cooley, Xu, Stock, and Joester, Proc Natl Acad Sci USA 2022, 119, e2211285119.
This work was in part supported by: NIH-NIDCR R03 DE025303-01 and R01 DE025702-01; NSF DMR-1508399 and DMR-1539918; and DOE DE-AC02-06CH11357.

BE Seminar: "Making Every Penny Count: Copper Conducted Kinase Signaling & Metabolism in Cancer"
2024-11-21 15:30 - 16:30 | 216 Moore Building
This seminar will be held in Moore 216 and remotely via zoom (check email for zoom link). Light refreshments will be served.

Fall 2024 GRASP on Robotics: Robert Katzschmann, ETH Zürich, "Building Life-like Robots: From Musculoskeletal Designs to Biohybrid Innovations"
2024-11-22 10:30 - 11:45 | Wu and Chen Auditorium (Room 101), Levine Hall, 3330 Walnut Street, Philadelphia, PA, 19104, United States
This will be a hybrid event with in-person attendance in Wu and Chen and virtual attendance on Zoom.
ABSTRACT
Nature’s musculoskeletal design can inspire both artificial and living robots to create systems that can better interact within our unstructured world. There is value in rethinking how we design and control robots by replacing traditional designs centred around electromagnetic motors and gearboxes with a bio-inspired approach that uses contractive muscles, ligaments, tendons, and skeletons. Taking it even a step further, living robots represent the next frontier in engineering materials for robotic systems, incorporating biological living cells and synthetic materials into their design. These bio-hybrid robots are dynamic and intelligent, potentially harnessing living matter’s capabilities, such as growth, regeneration, morphing, biodegradation, and environmental adaptation. Such attributes position bio-hybrid devices as a transformative force in robotics development, promising enhanced dexterity, adaptive behaviours, sustainable production, robust performance, and environmental stewardship. In this talk, we will explore recent advances in artificial electrohydraulic musculoskeletal robots, which employ electrohydraulic actuators to produce lifelike muscle contractions and adaptive motions, as demonstrated in our recent work published in Nature Communications. We will also dive deeper into our breakthroughs in vision-controlled inkjet printing for robotics from our Nature and xolographic biofabrication techniques, which enabled our biohybrid swimmers presented at RoboSoft. Additionally, we will discuss the computational optimisation of musculoskeletal robotic hands from our recent work presented at Humanoids. The talk will showcase how musculoskeletal, bio-hybrid, and computational techniques open new frontiers in robotics interaction and manipulation.
