Calendar of MRSEC Events
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2023 Events
8:30-9:30am EST | 24 Oxford Street, Room 375 - Classroom 375, Cambridge, MA
How are crystals formed?
Where can we see patterns in our daily lives?
Beauty and wonder surround us everyday. Our world is full of amazing patterns: from the smallest scale of molecules arranging into crystal structures such as snowflakes, to the stripes on a tiger, to large geological wonders like Devils Postpile. Join us at the 2023 Holiday Science Lecture for Families as we take a close look at some of the amazing patterns observed in nature and the science of their structure and formation. We will use experiments and interactive demonstrations to illustrate ideas of shape, symmetry, packing, and pattern formation!
Register for workshop
9am-6pm EST | 24 Oxford Street, Geological Lecture Hall, Cambridge, MA
Register for MSI BAARN Meeting
6 - 7:30pm | Pierce Hall 209, 29 Oxford Street
Bio: Louison Thorens obtained his master's degree in physics from the Ecole Normale Supérieure de Lyon in France, followed by a Ph.D. achieved through a collaborative effort between PoreLab at the University of Oslo in Norway and the Ecole Normale Supérieure de Lyon in France. My doctoral research focused on magnetic granular materials and flow in porous media, which serves as the basis of this talk. I am currently a postdoctoral researcher at Tufts University working with Jeffrey Guasto, my research now primarily explores polymer dynamics and stretching within microfluidic flows.
More about the Squishy Physics Seminar
Harvard University
8:30-9:30am EST | 24 Oxford Street, Room 375 - Classroom 375, Cambridge, MA
Register for MSI Chalk Talk
6 - 7:30pm | Pierce Hall 209, 29 Oxford Street
Inspired by these recent advances, here we show that by mixing highly deformable shells into an incompressible fluid we can realize a metafluid with programmable elastic response, optical behavior and viscosity. We show that the reversible buckling of the shells radically changes the characteristics of the fluid and provides exciting opportunities for expanding its functionality. First, we experimentally demonstrate both at centimeter and micrometer scale that the buckling of the shells endows the fluid a highly nonlinear behavior. Then, we numerically study how the shells geometry affects such nonlinear response. Finally, we harness the nonlinear fluid behavior to develop smart robotic systems, highly tunable logic gates and optical elements with switchable response. Further, we demonstrate that shell buckling also affects the fluid viscosity, making the flow in the laminar regime dependent not only on the pressure difference between two points but also on the absolute value of pressure at these points. As such, the proposed metafluid provides a promising platform to enhance the functionality of existing fluidic devices by expanding the capabilities of the fluid itself.
More about the Squishy Physics Seminar
6 - 7:00pm EST | 24 Oxford Street, Haller Hall, Geo Room 375, Cambridge, MA
More information about the MSI Seminar
MSI Coffee Hour Sign-Up with Dr. Amir Mitchell for November 17, 10am
6 - 7:30pm | Pierce Hall 209, 29 Oxford Street
More about the Squishy Physics Seminar
8:30-9:30am EST | 24 Oxford Street, Room 375 - Classroom 375, Cambridge, MA
6 - 7:30pm | Pierce Hall 209, 29 Oxford Street
More about the Squishy Physics Seminar
8:30-9:30am EST | 24 Oxford Street, Room 375 - Classroom 375, Cambridge, MA
6 - 7:30pm | Pierce Hall 209, 29 Oxford Street
More about the Squishy Physics Seminar
4 - 5pm | Pierce Hall 209, 29 Oxford Street
More about the Squishy Physics Seminar
8:30-9:30am EST | 24 Oxford Street, Room 375 - Classroom 375, Cambridge, MA
Register for MSI Chalk Talk
1:00pm EST | 20 Garden Street, Room G10, Cambridge, MA and VIRTUAL
The cell nucleus is enveloped by a complex membrane, whose wrinkling has been implicated in disease and cellular aging. The biophysical dynamics and spectral evolution of nuclear wrinkling during multicellular development remain poorly understood due to a lack of direct quantitative measurements. We characterize the onset and dynamics of nuclear wrinkling during egg development in the fruit fly when nurse cell nuclei increase in size and display stereotypical wrinkling behaviour. A spectral analysis of three-dimensional high-resolution live-imaging data from several hundred nuclei reveals a robust asymptotic power-law scaling of angular fluctuations consistent with renormalization and scaling predictions from a nonlinear elastic shell model. We further demonstrate that nuclear wrinkling can be reversed through osmotic shock and suppressed by microtubule disruption, providing tunable physical and biological control parameters for probing the mechanical properties of the nuclear envelope, highlighting in passing the importance of nonlinear response to biological robustness.
More information about the Center of Mathematical Sciences and Applications Active Matter Seminar
6 - 7:30pm | Pierce Hall 209, 29 Oxford Street
More about the Squishy Physics Seminar
6 - 7:00pm EST | 24 Oxford Street, Haller Hall, Geo Room 375, Cambridge, MA
The Crawford laboratory focuses on Metabolism at the Human-Microbe Interface. Genome sequencing of bacteria (and fungi) has revealed many highly unusual “orphan” biosynthetic gene clusters suspected of synthesizing novel, structurally diverse, and biologically active small molecules. These types of naturally produced molecules often regulate complex interactions with their animal hosts, hold a rich history of being utilized as human drugs, and serve as excellent molecular probes for identifying new drug targets for a wide variety of diseases. Additionally, there are still many novel metabolites of functional relevance in well-characterized animals, such as humans and mice. Using a blend of small molecule chemistry, protein biochemistry, cell biology, and microbiology, the lab exploits the natural interactions between bacteria and animals to discover new molecules with signaling, antimicrobial, immunomodulatory, and anticancer activities. The lab also connects these products to their underlying biosynthetic genes, characterizes the biosynthetic enzymes involved in their construction, and investigates their roles in biology and medicine. In this talk, I will provide an overview of our approaches and then dig into a few new metabolic systems that are conserved in a variety of gammaproteobacterial pathogens that regulate virulence programming. More information about the MSI Seminar
6 - 7:30pm | Pierce Hall 209, 29 Oxford Street
More about the Squishy Physics Seminar
8:30-9:30am EST | 24 Oxford Street, Room 375 - Classroom 375, Cambridge, MA
1:00pm EST | 20 Garden Street, Room G10, Cambridge, MA and VIRTUAL
Various processes in living cells depend on contractile forces that are often generated by myosin motors in concert with polar actin filaments. A textbook example of this is the actomyosin contractile ring that forms during cell division. Recent evidence, however, has begun to suggest alternate or redundant mechanisms that do not depend on myosin. Experiments on simplified, reconstituted systems also point to contractility and structure formation in disordered, apolar arrays of filaments. We propose a motor-free mechanism that can generate contraction in biopolymer networks without the need for motors such as myosin or polar filaments such as actin. This mechanism is based on active binding and unbinding of cross-linkers that breaks the principle of detailed balance, together with the asymmetric force-extension response of semiflexible biopolymers. We discuss the resulting force-velocity relation and other implications of this, as well as possible evidence for non-motor force generation.
More information about the Center of Mathematical Sciences and Applications Active Matter Seminar
6 - 7:30pm | Pierce Hall 209, 29 Oxford Street
More about the Squishy Physics Seminar
8:30-9:30am EST | 24 Oxford Street, Room 375 - Classroom 375, Cambridge, MA
6 - 7:30pm | Pierce Hall 209, 29 Oxford Street
More about the Squishy Physics Seminar
1:00pm EST | 20 Garden Street, Room G10, Cambridge, MA and VIRTUAL
The more prosaic cousin of active matter, driven inactive matter, is still full of unexpected phenomena. I will discuss two projects involving two seemingly mundane systems, a phase-separating colloidal mixture and a lipid membrane, which demonstrate counterintuitive properties when driven out of equilibrium. We will see that the phase separating mixture, when driven by a uniform force, develops (in simulations) an intriguing pattern with a characteristic length scale set by the magnitude of the drive. We will look at some theoretical approaches to understanding the pattern formation and possible experimental realizations. The membrane, when driven by an oscillatory electric field, develops (in experiments) a long-lived metastable state with a decreased capacitance and increased dissipation. This state may have implications for neuronal processing and memory formation.
More information about the Center of Mathematical Sciences and Applications Active Matter Seminar
6 - 7:00pm EST | 24 Oxford Street, Haller Hall, Geo Room 102, Cambridge, MA
More information about the MSI Seminar
Brandeis University
8:30-9:30am EST | 24 Oxford Street, Room 375 - Classroom 375, Cambridge, MA
8:30-9:30am EST | 24 Oxford Street, Room 375 - Classroom 375, Cambridge, MA
1:00pm EST | 20 Garden Street, Room G10, Cambridge, MA and VIRTUAL
Cell fate decisions are made by allowing external signals to govern the steady-state pattern adopted by networks of interacting regulatory factors governing transcription and translation. One of these decisions, of importance for both developmental processes and for cancer metastasis, is the epithelial-mesenchymal transition (EMT). In this talk, we will argue that these biological networks have highly non-generic interaction structures such that they allow for phenotypic states with very low frustration, i.e. where most interactions are satisfied. This property has important consequences for the allowed dynamics of these systems.
More information about the Center of Mathematical Sciences and Applications Active Matter Seminar
12:00pm EST | 52 Oxford Street, Northwest Building, Lecture Hall B103, Cambridge, MA
Lyme disease is a tick-borne disease caused by bacteria of the genus Borrelia. The host factors that modulate susceptibility for Lyme disease have remained mostly unknown. Using epidemiological and genetic data as well as in vitro and in vivo infection assays we show a novel host defense protein in humans present in the skin, sweat, and other secretions which protects against Borrelia bacteria.
More information about the MSI Seminar
6 - 7:30pm | Pierce Hall 209, 29 Oxford Street
More about the Squishy Physics Seminar
Dave Arnold (@CookingIssues), Booker and Dax (NYC), author of "Liquid Intelligence", host of "Cooking Issues," founder of the Museum of Food and Drink
Harold McGee (@Harold_McGee), author of "On Food and Cooking", "Curious Cook", "Nose Dive: A Field Guide to the World's Smells"
8:30-9:30am EST | 24 Oxford Street, Room 375 - Classroom 375, Cambridge, MA
Register for MSI Chalk Talk
September 1
Conference on Big Data
1 Oxford Street, Harvard Science Center, Cambridge, MA and VIRTUAL
Organizers: Michael Douglas, CMSA, Harvard University; Yannai Gonczarowski, Economics and Computer Science, Harvard University; Lucas Janson, Statistics and Computer Science, Harvard University; Tracy Ke, Statistics, Harvard University; Horng-Tzer Yau, Mathematics and CMSA, Harvard University; Lu Yue, Electrical Engineering and Applied Mathematics, Harvard University.
Register for Big Data 2023
Registration is required.
3-day Science & Cooking Professional Development High School Chemistry & Food Workshop
Explore a variety of NGSS-aligned topics like ionic compounds, intermolecular forces, acids and pH, and chemical reactions by making classroom-ready food labs including fresh cheese, caramel, brown butter, and popping boba.
This workshop is primarily intended for high school science chemistry teachers. Since it centers around hands-on labs and discussions, limited space is available and full participation is required. Our application form outlines the expectations for full participation in this virtual format.
Participants will earn:
- PDPs for their work
- a certificate of completion from Harvard University
- a stipend for both completion of the professional development and implementation of activity during the school year
Register for RET PD Workshop, registration is required. More about Harvard MRSEC RET Workshop
2-day Science & Cooking Professional Development Middle School Science & Food Workshop
Explore a variety of NGSS-aligned topics like ionic compounds, intermolecular forces, acids and pH, and chemical reactions by making classroom-ready food labs including fresh cheese, caramel, brown butter, and popping boba.
This workshop is primarily intended for middle school science chemistry teachers. Since it centers around hands-on labs and discussions, limited space is available and full participation is required. Our application form outlines the expectations for full participation in this virtual format.
Participants will earn:
- PDPs for their work
- a certificate of completion from Harvard University
- a stipend for both completion of the professional development and implementation of activity during the school year
Register for RET PD Workshop, registration is required. More about Harvard MRSEC RET Workshop
August 1
2-day Science & Cooking Professional Development Workshop
VIRTUAL
Wed, Aug 2–Thur, Aug 3: High School (intended for High School Chemistry); 11am-5pm EST on Zoom
Explore a variety of NGSS-aligned topics like ionic compounds, intermolecular forces, acids and pH, and chemical reactions by making classroom-ready food labs including fresh cheese, caramel, brown butter, and popping boba.
This workshop is primarily intended for middle school science and high school chemistry teachers. Since it centers around hands-on labs and discussions, limited space is available and full participation is required. Our application form outlines the expectations for full participation in this virtual format.
Participants will earn:
- PDPs for their work
- a certificate of completion from Harvard University
- opportunities for stipends after implementation of activities
Register for RET PD Workshop, registration is required. More about Harvard MRSEC RET Workshop
6 - 7:30pm | Pierce Hall 209, 29 Oxford Street
More about the Squishy Physics Seminar
6 - 7:30pm | Biolabs 1065, 16 Divinity Street, Cambridge, MA and REMOTE
Zoom Online Seminar
More information about the Extavour Lab or about the Talk
6 - 7:30pm | Pierce Hall 209, 29 Oxford Street
More about the Squishy Physics Seminar
6 - 7:30pm | Pierce Hall 209, 29 Oxford Street
Bio: Kaitlyn Becker is an assistant professor in the Mechanical Engineering Department and recipient of the Doherty Professorship in Ocean Utilization at MIT. She completed her B.S. in Mechanical Engineering at MIT in 2009, after which she worked on subcutaneous defibrillators as a manufacturing engineer for Cameron Health Inc, and then worked on the development of various nanofabrication technologies and UV water treatment as a senior engineer for Nano Terra Inc. She completed her PhD in Professor Wood’s Microrobotics Lab in 2021 and was postdoctoral researcher in Professor Mahadevan’s Soft Math lab at Harvard University. Her primary research thrust is on gentle and adaptive soft robots for grasping and manipulation from the desktop to the deep sea and focuses on novel soft robotic platforms that add functionality through innovations at the intersection of design and fabrication. Her work has been featured on the covers of the journals Soft Robotics and Advanced Functional Materials, and in the Unseen Oceans special exhibit in the American Natural History Museum. Her robotic platforms have also been successfully tested at depths down to 3.5km on research vessels including the Nautilus (Ocean Exploration Trust), Falkor (Schmidt Ocean Institute), and the Rachel Carlson (MBARI). She is a recipient of a Microsoft graduate research scholarship and a NSF Graduate Research Fellowship. Outside of her research and teaching in Mechanical Engineering, she also teaches glassblowing in the Department of Material Science and Engineering at MIT, where she fuses art and applied engineering in her classes.
More about the Squishy Physics Seminar
Boston University
6 - 7:30pm | Pierce Hall 209, 29 Oxford Street
First, I will present our work on exploring evaporation from single nanopores. We have developed a novel microscope-based optical measurement to measure evaporation rates down to 10 aL/s from single nanopores. I will show that the ultimate evaporation flux from ultrathin silicon nitride nanopores is not limited by liquid transport to the interface and vapor removal from the interface, but by the interfacial evaporation kinetics and shows a strong diameter dependence. I will also show that the kinetically-limited evaporation from graphene nanopores can be much larger than that from silicon nitride nanopores due to edge facilitated evaporation and minimum contaminant accumulation.
Secondly, I will introduce our latest work on studying nanoparticle-blocked nanopore systems. We have found that, when nanoparticles with sizes larger than the diameter of a nanopore are electrophoretically driven towards the nanopore, they can be either electrokinetically trapped near the nanopore or physically block the nanopore based on their surface charge polarity. These two types of nanoparticle blockage modes can respond to various electrical or mechanical stimuli and show stimuli-responsive transport. I will show how we utilize such nanoparticle-blockage-induced stimuli-responsive transport to develop new applications for nanoparticle characterization, nanopore gating as well as bio-sensing.
Bio: Dr. Chuanhua Duan received his B.S. and M.S. degrees in Engineering Thermophysics from Tsinghua University in 2002 and 2004, respectively. He obtained his Ph.D. in Mechanical Engineering from the University of California at Berkeley in 2009 under the guidance of Prof. Arun Majumdar. After staying in Berkeley for two more years as a postdoctoral researcher at the Lawrence Berkeley National Laboratory, Dr. Duan joined the Department of Mechanical Engineering at Boston University as an assistant professor in 2012. He is currently an associate professor at BU ME, leading the Nanoscale Energy-Fluids Transport Laboratory. Among his honors, Dr. Duan received the Defense Advanced Research Project Agency Young Faculty Award (YFA) in 2018, the National Science Foundation Early Faculty Career Development Award (CAREER) in 2017, and the American Chemistry Society Petroleum Research Fund Doctoral New Investigator Award in 2013. His research focuses on the study of micro- and nanofluidic transport phenomena and the development of new fluidic devices/approaches for applications in healthcare, energy systems, and thermal management.
More about the Squishy Physics Seminar
6 - 7:30pm | Pierce Hall 209, 29 Oxford Street
More about the Squishy Physics Seminar
6 - 7:30pm | Pierce Hall 209, 29 Oxford Street
More about the Squishy Physics Seminar
Harvard University
6 - 7:30pm | Pierce Hall 209, 29 Oxford Street
More about the Squishy Physics Seminar
1:00pm EST | 20 Garden Street, Room G10, Cambridge, MA and VIRTUAL
Two recent projects from my lab that involve lineage trees of cells (the branching diagram that represents the ancestry and division history of individual cells). In the first project, we reconstructed the lineage trees of individual cancer cells from the patterns of randomly occurring mutations in these cells. We then inferred the age at which the cancer mutation first occurred and the rate of expansion of the population of cancer cells within each patient. To our surprise, we discovered that the cancer mutation occurs decades before diagnosis. For the second project, we developed microfluidic 'mother machines' that allow us to observe mammalian cells dividing across tens of generations. Using our observations, we calculated the correlation between the duration of cell cycle phases in pairs of cells, as a function of their lineage distance. These correlations revealed many surprises that we are trying to understand using hidden Markov models on trees. For both projects, I will discuss the mathematical challenges that we have faced and open problems related to inference from lineage trees.
Register for CMSA Active Matter Seminar
6 - 7:30pm | Pierce Hall 209, 29 Oxford Street
More about the Squishy Physics Seminar
9am - 5pm at Northwest Building, 52 Oxford Street, Cambridge, MA
Ticket registration required, $20 or $5 for Students & Postdocs, and is open to the public
1:00pm EST | 20 Garden Street, Room G10, Cambridge, MA and VIRTUAL
When competing species grow into new territory, the population is dominated by descendants of successful ancestors at the expansion front. Successful ancestry depends on the reproductive advantage (fitness), as well as ability and opportunity to colonize new domains. (1) Based on symmetry considerations, we present a model that integrates both elements by coupling the classic description of one-dimensional competition (Fisher equation) to the minimal model of front shape (KPZ equation). Macroscopic manifestations of these equations on growth morphology are explored, providing a framework to study spatial competition, fixation, and differentiation, In particular, we find that ability to expand in space may overcome reproductive advantage in colonizing new territory. (2) Variations of fitness, as well as fixation time upon differentiation, are shown to belong to distinct universality classes depending on limits to gain of fitness.
Register for CMSA Active Matter Seminar
6 - 7:30pm | Pierce Hall 209, 29 Oxford Street
More about the Squishy Physics Seminar
6 - 7:30pm | Pierce Hall 209, 29 Oxford Street
More about the Squishy Physics Seminar
12-1pm EST | 24 Oxford Street, Room 375 - Classroom 375, Cambridge, MA
Register for MSI Chalk Talk
1:00pm EST | 20 Garden Street, Room G10, Cambridge, MA and VIRTUAL
The sizes of many subcellular structures are coordinated with cell size to ensure that these structures meet the functional demands of the cell. In eukaryotic cells, these subcellular structures are often membrane-bound organelles, whose volume is the physiologically important aspect of their size. Scaling organelle volume with cell volume can be explained by limiting pool mechanisms, wherein a constant concentration of molecular building blocks enables subcellular structures to increase in size proportionally with cell volume. However, limiting pool mechanisms cannot explain how the size of linear subcellular structures, such as cytoskeletal filaments, scale with the linear dimensions of the cell. Recently, we discovered that the length of actin cables in budding yeast (used for intracellular transport) precisely matches the length of the cell in which they are assembled. Using mathematical modeling and quantitative imaging of actin cable growth dynamics, we found that as the actin cables grow longer, their extension rates slow (or decelerate), enabling cable length to match cell length. Importantly, this deceleration behavior is cell-length dependent, allowing cables in longer cells to grow faster, and therefore reach a longer length before growth stops at the back of the cell. In addition, we have unexpectedly found that cable length is specified by cable shape. Our imaging analysis reveals that cables progressively taper as they extend from the bud neck into the mother cell, and further, this tapering scales with cell length. Integrating observations made for tapering actin networks in other systems, we have developed a novel mathematical model for cable length control that recapitulates our quantitative experimental observations. Unlike other models of size control, this model does not require length-dependent rates of assembly or disassembly. Instead, feedback control over the length of the cable is an emergent property due to the cross-linked and bundled architecture of the actin filaments within the cable. This work reveals a new strategy that cells use to coordinate the size of their internal parts with their linear dimensions. Similar design principles may control the size and scaling of other subcellular structures whose physiologically important dimension is their length.
Register for CMSA Active Matter Seminar
6 - 7:30pm | Pierce Hall 209, 29 Oxford Street
1:00pm EST | 20 Garden Street, Room G10, Cambridge, MA and VIRTUAL
Motivated by the existence of membrane-less compartments in the chemically active environment of living cells, I will discuss the dynamics of droplets in the presence of active chemical reactions. Therefore, I will first introduce the underlying interplay between phase separation and active reactions, which can alter the droplet dynamics compared to equilibrium systems. A key feature of such systems is the emergence of concentration gradients even at steady states. In the second part of this talk, I will discuss how these gradients can trigger instabilities in the core of chemically active droplets, giving rise to a new non-equilibrium steady state of liquid spherical shells. Finally, I will present experimental and theoretical results discussing the existence and energetic cost of this non-equilibrium steady state in a coacervate system.
Register for CMSA Active Matter Seminar
4 - 5pm EST | William James Hall, Room 105, 33 Kirkland Street, Cambridge, MA
6 - 7:30pm | Pierce Hall 209, 29 Oxford Street
More about the Squishy Physics Seminar
University of Rhode Island
Invited Speakers:
Corey O'Hern, Yale University
Leslie Shor, University of Connecticut
Ian Wong, Brown University
Evan Wujcik, University of Maine
More about the 94th New England Complex Fluids
1:00pm EST | VIRTUAL
Morphogenesis, the process through which genes generate form, establishes tissue scale order as a template for constructing the complex shapes of the body plan. The extensive growth required to build these ordered substrates is fueled by cell proliferation, which, naively, should disrupt order. Understanding how active morphogenetic mechanisms couple cellular and mechanical processes to generate order remains an outstanding question in animal development. I will review the statistical mechanics of orientational order and discuss the observation of a fourfold orientationally ordered phase (tetratic) in the model organism Parhyale hawaiensis. I will also discuss theoretical mechanisms for the formation of orientational order that require both motility and cell division, with support from self-propelled vertex models of tissue. The aim is to uncover a robust, active mechanism for generating global orientational order in a non-equilibrium system that then sets the stage for the development of shape and form.
Register for CMSA Active Matter Seminar
6 - 7:30pm | Pierce Hall 209, 29 Oxford Street
9am - 5pm | Science & Cooking Lab, 1737 Cambridge Street, Cambridge, MA
Registration required
"The Science Behind Cheese"
12-1pm EST | 24 Oxford Street Room 375, Classroom 375, Cambridge, MA
6 - 7:30pm | Pierce Hall 209, 29 Oxford Street
The emphasis of this talk is placed on how photocrosslinkable polymers can be used to achieve tissue regeneration, for example, their fabrication into various scaffolds (electrospun fibers, microspheres, and 3D printed scaffolds) to reconstruct bones. Specifically, assisted by microfluidics, we have developed photocrosslinkable methacrylated gelatin (GelMA) based microspheres encapsulating human mesenchymal stem cells (MSCs) for bone repair. Due to the mild crosslinking conditions, we found that the GelMA microspheres can provide a favourable micro-environment for MSC survival, spreading, migration, proliferation and osteogenesis. In another study, we prepared a periosteum mimicking bone aid (PMBA) by electrospinning photocrosslinkable GelMA with L-arginine-based unsaturated poly(ester amide) (Arg-UPEA), and methacrylated hydroxyapatite nanoparticles (nHAMA). Upon light exposure, the resultant hydrogel fibrous scaffolds can solidify within seconds. Via controlling the crosslinking density, we can control the scaffolds’ mechanical and degradation property. The optimal scaffold was found to provide long term structural and functional support and mediation of physiological activity. With the aid of 3D printing, we developed 3D bone scaffolds made of photocrosslinkable nanocomposite ink consisting of tri-block poly (lactide-co-propylene glycol-co-lactide) dimethacrylate (PmLnDMA, m and n respectively represent the unit length of propylene glycol and lactide) and nHAMA. It is discovered that nHAMA can rapidly interact with PmLnDMA upon light exposure within 140 seconds and form an inorganic-organic co-crosslinked nanocomposite network. This bone ink was found to provide good mechanical support and bioactivity (allow for encapsulation and long-term release of growth factors) for bone regeneration.
More about the Squishy Physics Seminar
12-1pm EST | 24 Oxford Street Room 375, Classroom 375, Cambridge, MA
6 - 7:30pm | Pierce Hall 209, 29 Oxford Street
More about the Squishy Physics Seminar
1:00pm EST | VIRTUAL
Over the last two decades, major progress has been made in understanding the self-organization principles of active matter. A wide variety of experimental model systems, from self-driven colloids to active elastic materials, has been established, and an extensive theoretical framework has been developed to explain many of the experimentally observed non-equilibrium pattern formation phenomena. Two key challenges for the coming years will be to translate this foundational knowledge into functional active materials, and to identify quantitative mathematical models that can inform and guide the design and production of such materials. Here, I will describe joint efforts with our experimental collaborators to realize self-growing bacterial materials [1], and to implement computational model inference schemes for active and living systems dynamics [2,3].
Register for CMSA Active Matter Seminar
4 - 5pm EST | William James Hall, Room 105, 33 Kirkland Street, Cambridge, MA
6 - 7:30pm | Pierce Hall 301, 29 Oxford Street
More about the Squishy Physics Seminar
9am - 5pm | Science & Cooking Lab, 1737 Cambridge Street, Cambridge, MA
Registration required
"The Science Behind Cheese"
and March 9th
3:30-5:00pm EST | 20 Garden Street Room G10, Cambridge, MA and VIRTUAL
A brief intro to protein biology. AlphaFold2 impacts on experimental structural biology. Co-evolutionary approaches. Space of ‘algorithms’ for protein structure prediction. Proteins as images (CNNs for protein structure prediction). End-to-end differentiable approaches. Attention and long-range dependencies. AlphaFold2 in a nutshell.
Thursday, February 16, Lecture 2:
AlphaFold2 architecture. Turning the co-evolutionary principle into an algorithm: EvoFormer. Structure module and symmetry principles (equivariance and invariance). OpenFold: retraining AlphaFol2 and insights into its learning mechanisms and capacity for generalization. Applications of variants of AlphaFold2 beyond protein structure prediction: AlphaFold Multimer for protein complexes, RNA structure prediction.
Thursday, March 9, Lecture 3:
Limitations of AlphaFold2 and evolutionary ML pipelines. Current single sequence models. Protein language models (LM): single sequence + LM embeddings. Combining LM models with Frenet-Serret construction for protein structure prediction. Applying AlphaFold2 and OpenFold for language models.
Register for CMSA Special Lecture
1:00pm – 2:30pm (EST) | VIRTUAL or 20 Garden St, seminar room G-10
More about the Active Matter Seminar
4 - 5pm EST | William James Hall, Room 105, 33 Kirkland Street, Cambridge, MA
Register for MSI Thursday Seminar Series
2022 Events
6 - 7:30pm | Pierce Hall 301, 29 Oxford Street
More about the Squishy Physics Seminar
A*STAR Senior Fellow and Director of NanoBio Lab, Institute of Materials Research and Engineering and A*STAR Infectious Diseases Labs
4 - 5:30pm | Pierce Hall 209, 29 Oxford Street
We have also synthesized metallic, metal oxide, and semiconducting nanoclusters, nanocrystals and nanosheets of controlled dimensions and morphology. The nano-sized building blocks are used to create multifunctional systems with excellent dispersion and unique properties. Nanoporous materials of a variety of metal oxide and organic backbone have also been created with high surface areas and well-defined porosities. These nanostructured materials are successfully tailored towards energy and sustainability applications.
Speaker Bio:
Jackie Y. Ying received her Ph.D. from Princeton University. She was Professor of Chemical Engineering at MIT (1992-2005), and Founding Executive Director of Institute of Bioengineering and Nanotechnology, Singapore (2003-2018). She is currently A*STAR Senior Fellow and Director of NanoBio Lab, Institute of Materials Research and Engineering and A*STAR Infectious Diseases Labs.
For her research on nanomaterials and bioengineering, Prof. Ying has been recognized with the American Ceramic Society Purdy Award, David and Lucile Packard Fellowship, ONR Young Investigator Award, NSF Young Investigator Award, Camille Dreyfus Teacher-Scholar Award, ACS Faculty Fellowship Award in Solid-State Chemistry, Technology Review's Inaugural TR100 Young Innovator Award, AIChE Colburn Award, International Union of Biochemistry and Molecular Biology Jubilee Medal, Mustafa Prize "Top Scientific Achievement Award," Turkish Academy of Sciences Academy Prize in Science and Engineering Sciences, and Journal of Drug Targeting's Lifetime Achievement Award.
Prof. Ying is an elected Member of the German National Academy of Sciences-Leopoldina, and U.S. National Academy of Engineering. She is a Fellow of MRS, RSC, AIMBE, AAAS, and U.S. National Academy of Inventors. She was the Founding Editor-in-Chief of Nano Today.
More about the Special MRSEC Seminar
6 - 7:30pm | Pierce Hall 301, 29 Oxford Street
More about the Squishy Physics Seminar
10-11am and 1-2pm | Science & Engineering Complex, 150 Western Avenue, Allston, MA
Registration required
"Engine Earth: The Science of Our Climate System"
Harvard University
7 p.m. | 1 Oxford Street, Cambridge, MA, Science Center Hall C; and Instagram (@scicookharvard)
Contact: science_cooking@seas.harvard.edu
Pia Leon (@pialeonkjolle) Chef and Co-owner of Kjolle, Central (Lima, Perú), MIL (Cusco, Perú), World's Best Female Chef of 2021
Malena Martinez (@malenamater) Co-Director of Mater Iniciativa, Central
4 - 5pm EST | William James Hall, Room 105, 33 Kirkland Street, Cambridge, MA
1pm (EST) | CMSA, 20 Garden St, Seminar room G-10
More about the Active Matter Seminars
4:30pm (EST) | Jefferson 250 (17 Oxford Street)
More about the Active Matter Seminars
4:30pm (EST) | Jefferson 250 (17 Oxford Street)
More about the Active Matter Seminars
7 p.m. | 1 Oxford Street, Cambridge, MA, Science Center Hall C; and Instagram (@scicookharvard)
Contact: science_cooking@seas.harvard.edu
4:30pm (EST) | Jefferson 250 (17 Oxford Street)
More about the Active Matter Seminars
6 - 7:30pm | Pierce Hall 301, 29 Oxford Street
More about the Squishy Physics Seminar
12 - 1pm, 24 Oxford Street, Room 375, Cambridge, MA
Register for the Micro-Goal Hour
6 - 7:30pm | Pierce Hall 301, 29 Oxford Street
More about the Squishy Physics Seminar
7 p.m. | 1 Oxford Street, Cambridge, MA, Science Center Hall C; and Instagram (@scicookharvard)
Contact: science_cooking@seas.harvard.edu
Eduard Xatruch (@disfrutarbcn) Disfrutar and Compartir Barcelona
12 - 1pm, 24 Oxford Street, Room 375, Cambridge, MA
6 - 7:30pm | Pierce Hall 301, 29 Oxford Street
More about the Squishy Physics Seminar
7 p.m. | 1 Oxford Street, Cambridge, MA, Science Center Hall C; and Instagram (@scicookharvard)
Contact: science_cooking@seas.harvard.edu
Sean Sherman (@the_sioux_chef), Chef, Founder of The Sioux Chef, Co-Founder of NĀTIFS (North American Traditional Indigenous Food Systems), Co-Owner of Owamni by The Sioux Chef
4 - 5pm EST | William James Hall, Room 105, 33 Kirkland Street, Cambridge, MA
7 p.m. | 1 Oxford Street, Cambridge, MA, Science Center Hall C; and Instagram (@scicookharvard)
Contact: science_cooking@seas.harvard.edu
Bryan Furman (@bs_pitmaster), Pitmaster, Bryan Furman BBQ, B's Cracklin Barbecue, Chef in Residence at Stone Barns Center for Food & Agriculture
12 - 1pm, 24 Oxford Street, Room 375, Cambridge, MA
6 - 7:30pm | Pierce Hall 301, 29 Oxford Street
More about the Squishy Physics Seminar
7 p.m. | 1 Oxford Street, Cambridge, MA, Science Center Hall C; and Instagram (@scicookharvard)
Contact: science_cooking@seas.harvard.edu
Kate Strangfeld (@kate_cooks, @bitescizededucation), Founder of Bite Scized Education, Former Middle School Science and Chemistry Teacher, Washington International School
*This is a special session for teachers, educators, or anyone who is interested in using food to teach science
4 - 5pm EST | Biolabs Lecture Hall, Room 1080, 16 Divinity Avenue, Cambridge, MA
6 - 7:30pm | Pierce Hall 301, 29 Oxford Street
More about the Squishy Physics Seminar
"Tailoring Bulk and Interfacial Properties of Polymer Systems Through the Molecular Weight Distribution"
4:30 p.m. | Pierce Hall 209
Abstract: The dispersity, or breadth in the molecular weight distribution, is an inherent feature of synthetic polymer systems. Typically treated as an unfortunate consequence of polymer synthesis, here I will discuss how polymer dispersity can be tuned to generate novel function in bulk and interfacial properties. In bulk systems, I will show that both the shear and extensional rheology of mixtures of colloids and non-adsorbing polymers, a common model system for feedstocks for 3-D printing and coating, depend on the polymer dispersity. In interfacial systems, I will show how shaping the molecular weight distribution of surface-grafted polymer brushes can modulate both brush structure and stimulus response. Thus, molecular weight distributions represent an intriguing route for tailoring polymer properties.
7 p.m. | 1 Oxford Street, Cambridge, MA, Science Center Hall C; and Instagram (@scicookharvard)
Contact: science_cooking@seas.harvard.edu
Fatmata Binta (@chef_binta) Chef of "Dine on a Mat" and Founder of Fulani Kitchen Projects
CRISPR detection of circulating cell-free Mycobacterium tuberculosis DNA
Jimena Luque
Assessment of possible concerted chromosome loss in yeast
Llinca Mazureac
Growth rate regulation in rod shaped bacteria
Register for the Chalk Talk
6 - 7:30pm | Pierce Hall 301, 29 Oxford Street
More about the Squishy Physics Seminar
7 p.m. | 1 Oxford Street, Cambridge, MA, Science Center Hall C; and Instagram (@scicookharvard)
Contact: science_cooking@seas.harvard.edu
Chintan Pandya (@chefchintan) Chef and Partner of Unapologetic foods including Dhamaka, Adda, and Semma
Brandeis University
7 p.m. | 1 Oxford Street, Cambridge, MA, Science Center Hall C; and Instagram (@scicookharvard)
Contact: science_cooking@seas.harvard.edu
Arielle Johnson, Ph.D. (@arielle_johnson) Flavor Scientist, Gastronomy and Innovation Researcher, Co-founder of the Noma Fermentation Lab
6 - 7:30pm | Pierce Hall 301, 29 Oxford Street
More about the Squishy Physics Seminar
7 p.m. | 1 Oxford Street, Cambridge, MA, Science Center Hall C; and Instagram (@scicookharvard)
Contact: science_cooking@seas.harvard.edu
Joanne Chang '91 (@jbchang), Flour Bakery and Café, Myers + Chang, author of "Flour", "Flour Too", "Myers + Chang at Home", and "Baking With Less Sugar"
6 - 7:30pm | Pierce Hall 301, 29 Oxford Street
More about the Squishy Physics Seminar
1:00pm - 2:00pm (EST) | Remote
Based on our exploratory retrospective clinical study with N=1,380 breast cancer patients and vital cell tracking in patient-derived tumor explants, we find that the unjamming state diagram depends on cell and nucleus shapes as one variable and the nucleus number density as the other that measures the cytoplasmic spacing between the nuclei. Our approach unifies previously controversial results into one state diagram. It spans a broad range of states that cancer cell clusters can assume in a solid tumor. We can use an empirical decision boundary to show that the unjammed regions in the diagram correlate with the patient's risk for metastasis.
We conclude that unjamming within primary tumors is part of the metastatic cascade, which significantly advances the understanding of the early metastatic events. With the histological slides of two independent breast cancer patients' collectives, we train (N=688) and validate (N=692) our quantitative prognostic index based on unjamming regarding metastatic risk. Our index corrects for false high- and low-risk predictions based on the invasion of nearby lymph nodes, the current gold standard. Combining information derived from the nodal status with unjamming may reduce over- and under-treatment.
More about the Active Matter Seminar
7 p.m. | 1 Oxford Street, Cambridge, MA, Science Center Hall C; and Instagram (@scicookharvard)
Contact: science_cooking@seas.harvard.edu
Dave Arnold (@CookingIssues), Booker and Dax, author of "Liquid Intelligence", host of "Cooking Issues," founder of the Museum of Food and Drink
Harold McGee (@Harold_McGee), author of "On Food and Cooking", "Curious Cook", "Nose Dive: A Field Guide to the World's Smells"
6 - 7:30pm | Pierce Hall 301, 29 Oxford Street
More about the Squishy Physics Seminar
Mt. Holyoke College (50 College Street, South Hadley, MA)
This 2022 Gordon Research Conference brings together experts from a range of synergistic and complementary disciplines (mathematics/physics, engineering, microbiology/virology, epidemiology) to exchange on frontier research in health, including respiratory/nosocomial infectious diseases transmission and public health, where bio- and fluid physics are at the core.
The fantastic line-up of participants covers a wide range of fields to continue our 2019 effort to build a sustained and solid intellectual foundation and connected community. Thought and program leaders come together with young researchers to address the subtle and complex challenges of the growing intersection between fluid physics, biophysics, soft matter, infectious diseases and contamination across scales.
Note that applicants for posters or attendance can be in areas that are much broader than "infectious disease transmission." Similarly to the F&H 2019 conference, this GRC 2022 iteration will involve discussions on technical, theoretical, methodological, and translational challenges relevant for a range of open scientific questions at the intersection of virology/microbiology/physiology/mechanics/fluid mechanics, biophysics/soft matter, mixing/soft matter/applied math/modelling and health broadly defined. So those in these areas should also consider applying for the posters and attendance!
Please apply before attending
6 - 7:30pm | Pierce Hall 301, 29 Oxford Street
More about the Squishy Physics Seminar
Wednesday, August 3rd: 10am - 3pm | Maxwell Dworkin 119, 33 Oxford Street
Thursday & Friday, August 4 & 5: 10am - 3pm, Allston SEC 1.321
11:00 AM to 1:00 PM | Pierce Hall 209 (29 Oxford St, Cambridge)
- Setting up a (local) repository
- Adding, committing, stashing, reverting, resetting...
- Branching, merging
- Example of best practices (e.g. tracking code vs ignoring large output data)
- Remote vs local branches
- Pull requests and merging
- Forking
- Issues
- Project planning
- Wiki
The meeting will have two sessions, each will last 50 minutes.
Session 1: 11:00 - 11:50 AM
Session 2: 12:00 - 12:50 PM
Lunch: 1:00 PM
10 am to 2 pm | Pierce Hall 209 (29 Oxford St, Cambridge)
For the first lecture, we will talk about shadowgraphy and Schlieren methods that are the method to detect the difference of the refractive index in fluid media. By using the distortion of the light ray through a different fluid, we can observe the motion of fluid.
Secondly, the most conventional flow visualization technique will be introduced, so-called particle image velocimetry (PIV). In this lecture, to perform PIV, three main aspects are discussed, particle, light source, and optics. Furthermore, the optimal conditions for achieving a good vector field are summarized and explained.
Lastly, we will shortly discuss micro-PIV, which is for microfluidics applications. Some distinct features compared to conventional PIV are treated during the lecture.
The meeting will have three sessions, each will last 50 minutes.
Session 1: 10:00 - 10:50 AM
Session 2: 11:00 - 11:50 AM
Lunch: 12:00 - 1:00 PM
Session 3: 1:00 - 1:50 PM
Please register before attending
Dr. Dave Weitz's Lab, 9 Oxford St - LISE 424
About the Leica Stellaris 8 Confocal Demonstration
UMass Boston
6 - 7:30pm | Pierce Hall 301, 29 Oxford Street
More about the Squishy Physics Seminar
6 - 7:30pm | Pierce Hall 301, 29 Oxford Street
Motivated by these experiments we address Stokes flow in a curved film of a non-inertial incompressible liquid with free surfaces, generated by temporal variation of the Gaussian curvature R [4]. Notwithstanding the close analogy between the Newtonian hydrodynamics of viscous liquids and the Hooeakn elasticity of solids, often called “Stokes-Rayleigh analogy”, the fact that stress in viscous films is generated by the rate-of-change ∂tR, rather than by R itself as is the case for elastic sheets, reflects a profound difference between these two branches of non-inertial, yet geometrically-nonlinear continuum mechanics. Whereas the rigidity of elastic sheets derives from the existence of a “target” metric, their viscous counterparts are not endowed with a preferred metric. We reveal the experimental observations of Ref. [3] as a dramatic ramification of this distinction - a universal, curvature-driven & momentum-conserving surface dynamics, imparted by viscous resistance to ∂tR ̸= 0. Specifically, rapidly-depressurized viscous bubbles flatten by forming a radially moving front of highly localized ∂tR that separate a flat core and a spherically-shapes periphery, and become wrinkled due to a hoop-compressive stress field at the wake of the propagating front [5].
This novel surface dynamics has close ties to "Jelium physics", where topological defects spontaneously emerge to screen elastic stress, similarly to dipoles-mediated screening of electrostatic field in conducting media, thereby extending the classic analogy between Wigner crystals, Abrikosov lattice in type-II superconductors, and 2D elasticity of curved crystals, to non-equilibrium 2D viscous hydrodynamics. A particularly exciting possibility is the emergence of such a universal geometrically-noninear 2D viscous hyrodynamics in strongly-correlated electronic liquids in 2D crystals.
[1] G. Debregeas, P.G. de Gennes, F. Brochard-Wyart, "The life and death of 'bare' viscous bubbles," Science 279, 1704-1707 (2000).
[2] R. da Silviera, S.Chaieb, L.Mahadevan, "Rippling instability of a collapsing bubble," Science 287, 1468-1471 (2000).
[3] A.T. Oratis, J.W.M. Bush, H.A. Stone, J. Bird, "A new wrinkle on liquid sheets: Turning the mechanism of viscous bubble collapse upside down," Science 369, 685 (2020).
[4] P.D. Howell, "Models for thin viscous sheets," Eur. J. App. Math. 7, 321-343 (1996).
[5] B. Davidovitch and A. Klein, "How viscous bubbles collapse: topological and symmetry- breaking instabilities in curvature-driven hydrodynamics" (2022).
More about the Squishy Physics Seminar
6 - 7:30pm | Pierce Hall 301, 29 Oxford Street
I will explore this possibility through experiments at macro and micro scales and numerical simulations. The coupling between the acoustic wave and the self-oscillation of the deformed shell leads to complex - sometimes chaotic - dynamics with direct consequences on the direction and efficiency of the swimming.
More about the Squishy Physics Seminar
6 - 7:30pm | Pierce Hall 301, 29 Oxford Street
- V. Nguyen et. al., Evolutionary Drivers of Thermoadaptation in Enzyme Catalysis” Science 2017, 355(6322):289-294
- J. B. Stiller et. al., Probing the Transition State in Enzyme Catalysis by High-Pressure NMR Dynamics 2019, Nature Catalysis (2019) 2, 726–734
- J. B. Stiller et. al., Structure Determination of High-Energy States in a Dynamic Protein Ensemble Nature 2022, in press
- R. Otten et. al., How directed evolution reshapes energy landscapes in enzymes to boost catalysis Science 2020, 2020 Dec 18;370(6523):1442-1446
6 - 7:30pm | Pierce Hall 301, 29 Oxford Street
Here, we use Lagrangian analysis techniques to study the chaotic flow fields gen- erated by bacterial turbulence in dense suspensions of Bacillus subtilis. High- resolution velocity fields are measured using PIV across a range of bacterial swimming speeds, where the computed Lagrangian stretching visualizes the induced stretching and folding, characteristic of mixing. Close inspection of the finite-time Lyapunov exponent (FTLE) field reveals time and swimming speed dependent FTLE statistics reminiscent of intermittent dynamics in clas- sical chaotic dynamical systems. At moderate P ́eclet numbers, experiments and Langevin simulations reveal that manifolds of the FTLE field guide scalar mix- ing and regulate transport in these active suspensions, ecologically relevant to the dispersal of chemical resources and particulates in dense bacterial colonies.
Secondly, we apply proper orthogonal decomposition (POD) analysis to quantify the dynamical flow structure of active turbulence under a variety of conditions. In isotropic bulk turbulence, the modal representation shows that the most en- ergetic flow structures dictate the spatio-temporal dynamics across a range of suspension activity levels. In confined geometries, POD analysis illustrates the role of boundary interactions for the transition to bacterial turbulence, and it quantifies the evolution of coherent active structures in externally applied flows. Beyond establishing the physical flow structures underpinning the complex dy- namics of bacterial turbulence, the low-dimensional representation afforded by this modal analysis will facilitate data-driven modeling of active turbulence.
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9am - 6pm at Northwest Building, 52 Oxford Street, Cambridge, MA
Registration required, is free, and is open to the public
Speakers: Libusha Kelly, John F. Brooks II, Otto X. Cordero, Sophie Helaine, Andrea Giometto, Robinson Fulweiler, Karla Fullner Satchell, and Karthik Anantharaman
1:00pm - 2:30pm (EST) | Remote
More about the Active Matter Seminar
6 - 7:30pm | Pierce Hall 301, 29 Oxford Street
In this talk, building on model experiments based on Quincke rollers, I will first explain how a flock suppresses its singularities to form an ordered spontaneous flow. Combining experiments, simulations and theory I will show how to elucidate the elementary excitations of 2D polar active matter and explain their phase ordering dynamics as a self-similar process emerging from the annihilation of ±1 defects along a filamentous network of domain walls with no counterparts in passive systems.
In a second part, I will address the robustness of long range order and discuss the stabilization of topological defects in a polar active fluid through disordered media. Combining experiments and theory, I will show that colloidal flocks collectively cruise through disorder without relaxing the topological singularities of their flows, unlike in pure systems. Introducing colloidal flocks in micro patterned circular chambers, we reveal a state of strongly disordered active matter with no counterparts in equilibrium : a dynamical vortex glass. The resulting state is highly dynamical but the flow patterns, shaped by a finite density of frozen vortices, are stationary and exponentially degenerated.
More about the Squishy Physics Seminar
6 - 7:30pm | Pierce Hall, room 301, 29 Oxford Street
More about the Squishy Physics Seminar
1:00pm - 2:30pm (EST) | Remote
More about the Active Matter Seminar
6 - 7:30pm | Pierce Hall, room 301, 29 Oxford Street
More about the Squishy Physics Seminar
6 - 7:30pm | Pierce Hall, room 301, 29 Oxford Street
Despite our detailed knowledge of the spindle's molecular composition, as mechanical objects, both meiotic and mitotic spindles are very poorly understood. It is not known, for instance, which specific molecular or structural components of the spindle are responsible for generating the forces that actually move chromosomes, or which components transfer those forces to chromosomes. Likewise, from a materials physics perspective, it is unclear how we should think about self-organized, biochemically complex, fuel-consuming structures like the spindle.
In this talk, I will discuss how we can adapt a variety of tools from materials physics to characterize various aspects of the spindle's microscopic structure and organelle-scale physical properties, like elastic stiffness and surface tension. I will discuss our attempts to understand these measurements within the context of a quantitative, coarse-grained theory in which spindles from mouse and human eggs are modeled as active liquid crystal droplets.
More about the Squishy Physics Seminar
4 - 5pm EST | Remote meeting
Register for (remote only) MSI Thursday Seminar Series
6 - 7:30pm | Pierce Hall, room 301, 29 Oxford Street
More about the Squishy Physics Seminar
1:00pm - 2:30pm (EST) | Remote
More about the Active Matter Seminar
6 - 7:30pm | Pierce Hall, room 301, 29 Oxford Street
More about the Squishy Physics Seminar
Northeastern University
12 - 1pm, 24 Oxford Street, Room 375, Cambridge, MA
6 - 7:30pm | Pierce Hall, room 301, 29 Oxford Street
Coarse-graining involves two coupled learning problems: defining the mapping from an all-atom representation to a reduced representation, and parameterizing a Hamiltonian over coarse-grained coordinates. We have recently proposed a generative modeling framework based on variational auto-encoders to unify the tasks of learning discrete coarse-grained variables and parameterizing coarse-grained force fields. Furthermore, CG approaches result in irreversible information loss, which makes accurate backmapping, i.e., restoring fine-grained (FG) coordinates from CG coordinates, a long-standing challenge. We propose a model that rigorously embeds the probabilistic nature and geometric consistency requirements of the backmapping transformation. The model encodes the distribution of FG expansions of the beads into an invariant latent space and decodes them back to FG geometries via equivariant convolutions.
1:00pm - 2:30pm (EST) | Remote
I will then discuss various strategies to tame, otherwise chaotic, active flows, showing how hydrodynamic screening of active flows can act as a robust way of controlling and guiding active particles into dynamically ordered coherent structures. I will also explain how combining hydrodynamics with topological constraints can lead to further control of exotic morphologies of active shells.
More about the Active Matter Seminar
6 - 7:30pm | Pierce Hall, room 301, 29 Oxford Street
12 - 1pm, 24 Oxford Street, Room 375, Cambridge, MA
6 - 7:30pm | Pierce Hall, room 301, 29 Oxford Street
1:00pm - 2:30pm (EST) | Remote
More about the Active Matter Seminar
6 - 7:30pm | Pierce Hall, room 301, 29 Oxford Street
6 - 7:30pm | Pierce Hall, room 301, 29 Oxford Street
1:00pm - 2:30pm (EST) | Remote
More about the Active Matter Seminar
2021 Events
Samuel Lim, Harvard Medical School
6 - 7:30pm | Pierce Hall, room 301, 29 Oxford Street
Katie Galloway, Department of Chemical Engineering, MIT
6 - 7:30pm | Pierce Hall, room 301, 29 Oxford Street
Harvard University
Alberto Fernandez-Nieves, Department of Condensed Matter Physics. University of Barcelona & ICREA
6 - 7:30pm | Pierce Hall, room 301, 29 Oxford Street
Dr. Isaac Chiu, Associate Professor of Immunology, Department of Immunology, Harvard Medical School
6 - 7:30pm | Pierce Hall, room 209, 29 Oxford Street
Watch "Bacterial Interactions with Pain and Itch" on YouTube
Hyoungsoo Kim, Department of Mechanical Engineering, KAIST, South Korea
6 - 7:30pm | Pierce Hall, room 209, 29 Oxford Street
TBD title
7 p.m. | Harvard SEAS Webinar
Contact: science_cooking@seas.harvard.edu
Ted Russin (@CIACulinarySci) School of Culinary Science and Nutrition, Culinary Institute of America
Aereas Aung, Koch Institute, MIT
6 - 7:30pm | Pierce Hall, room 209, 29 Oxford Street
Noah Mitchell, University of California, Santa Barbara
2:30 - 3:30pm | Maswell-Dworkin, room G125, 29 Oxford Street
James Banal, Department of Biological Engineering, MIT
6 - 7:30pm | Pierce Hall, room 209, 29 Oxford Street
"The Science of Ice Cream"
7 p.m. | Harvard SEAS Webinar
Contact: science_cooking@seas.harvard.edu
Carlos Conte, Department of Biochemistry, Federal University of Rio de Janeiro
6 - 7:30pm | Pierce Hall, room 209, 29 Oxford Street
Contact: science_cooking@seas.harvard.edu
"Chocolate Techniques: From Tempering to Ganache"
7 p.m. | Harvard SEAS Webinar
Carlos Conte, Department of Biochemistry, Federal University of Rio de Janeiro
6 - 7:30pm | Pierce Hall, room 209, 29 Oxford Street
Andreas Bausch, Center for functional Protein Assemblies (CPA), Chair for Cellular Biophysics, Technical University Munich
6 - 7:30pm | Pierce Hall, room 209, 29 Oxford Street
"Thermo Dynamics of BBQ"
7 p.m. | Harvard SEAS Webinar
Contact: science_cooking@seas.harvard.edu
"FOOLING THE EYE, TRICKING THE TONGUE: Breaking Flavor Associations with Vegetables"
7 p.m. | Harvard SEAS Webinar
Contact: science_cooking@seas.harvard.edu
"The Science of Hand Pulled Noodles"
7 p.m. | Harvard SEAS Webinar
Contact: science_cooking@seas.harvard.edu
Watch "The Science of Hand Pulled Noodles" on YouTube
Brandeis University
"Fermentation: A Springboard for Modern Gastronomy"
12-1:15 p.m. | Harvard SEAS Webinar
(Virtual presentation only; join us on Instagram Live @scicookharvard)
Contact: science_cooking@seas.harvard.edu
Watch "Fermentation: A Springboard for Modern Gastronomy" on YouTube
"The Science of Sugar"
7 p.m. | Harvard SEAS Webinar
Contact: science_cooking@seas.harvard.edu
Watch "The Science of Sugar" on YouTube
"Miracles of Moisture Management"
7 p.m. | Harvard SEAS Webinar
Contact: science_cooking@seas.harvard.edu
Harold McGee (@mcgee.onfood.onsmells), author of "On Food and Cooking," "Curious Cook," "Nose Dive: A Field Guide to the World's Smells"
MIT
9am - 4:30pm | Remote meeting
Instabilities and liquid to solid transition in a three-dimensional active network
Margaret Gardel, University of Chicago
Building soft, living materials
Mathias Kolle, MIT
Optical emulsions, focused and in color
Chinedum Osuji, University of Pennsylvania
Block Copolymer Assembly Nematic Solvents
Lillian Fritz-Laylin
11am - noon | Remote meeting
Title: TBA
Allyson Sgro11am - noon | Remote meeting
Marino Arroyo
11am - noon | Remote meeting
Crawling of Euglena cells by large-amplitude shape changes
Katy Rothenberg11am - noon | Remote meeting
Rashmi Priya
11am - noon | Remote meeting
Local tension imbalance drives global organ patterning and fate specification
Mohit Kumar Jolly11am - noon | Remote meeting
Tim Atherton, Tufts University
1pm EST | Remote meeting
Jude Phillip
11am - noon | Remote meeting
Title: TBA
Shashank Shekhar11am - noon | Remote meeting
Robert Fischer
11am - noon | Remote meeting
Riding the wave: how ECM waves can depolarize cancer cells
Isabelle Caille11am - noon | Remote meeting
Primary cilium-dependent cAMP/PKA signalling at the centrosome regulates neuronal migration
Spoorthi Subramaniam
11am - noon | Remote meeting
Guidance mechanisms involved in melanocyte patterning and survival
Jorg Renkawitz11am - noon | Remote meeting
Leukocyte navigation in 3D microenvironments
Dr. Arash Komeili, UC Berkeley
12 - 1pm EST | Remote meeting
Watch "The ins and outs of bacterial organelles" on YouTube
Michael Hagan, Brandeis University
1pm EST | Remote meeting
Bojana Gligorijevic
11am - noon | Remote meeting
Real-time microscopy of invasive cancer cells in the tumor microenvironment context
University of Rhode Island
Eva Crosas Molist
11am - noon | Remote meeting
AMPK is a mechano-metabolic sensor linking mitochondrial dynamics to Myosin II dependent cell migration
Vicky Sans Moreno11am - noon | Remote meeting
The actomyosin cytoskeleton in cancer: cell migration and beyond
Changyeob Baek, Harvard University
1pm EST | Remote meeting
First, I'll present triaxial weaving, a craft technique used to generate surfaces using tri-directional arrays of initially straight elastic ribbons. We achieve smooth, three-dimensional weaved structures by prescribing in-plane curvatures to the flat ribbons. The potential of this novel design scheme is demonstrated with a few canonical target shapes.
Second, I'll present the mechanics of two elastic rods in a crossing contact, whose geometric counterpart is often referred to in the mathematics community as a ‘clasp.' We compare our experimental and computational results to a well-established description for ideal clasps of geometrically rigid strings, finding that the latter acts as an underlying ‘backbone' for the full elasticity solution.
Samantha Payne
11am - noon | Remote meeting
Cortical actin properties controlled by Drosophila Fos aid macrophage infiltration against surrounding tissue resistance
Madeleine Oudin11am - noon | Remote meeting
Title: TBA
Vera Belyaeva
4 - 5pm | Remote meeting
Cortical actin properties controlled by Drosophila Fos aid macrophage infiltration against surrounding tissue resistance
Marcus Bischoff11am - noon | Remote meeting
Coordination of cytoskeletal dynamics during the transition from migration to apical constriction during Drosophila abdominal morphogenesis
Dr. Severine Atis, Duke University
1pm EST | Remote meeting
Abstract: Biological systems can self-organize in complex structures, able to evolve and adapt to widely varying environmental conditions. Despite the importance of fluid flow for transporting and organizing populations, few laboratory systems exist to systematically investigate the impact of advection on their spatial evolutionary dynamics. In this talk, I will show how we can address this problem by studying the morphology and genetic spatial structure of microbial colonies growing on the surface of a viscous substrate. I will illustrate how the interplay between microbial growth geometry, metabolic activity and fluid flows can generate positive feedback with the environment and lead to accelerated propagation, fragmentation of the initial colony and the formation of growing microbial jets.
Bio: Dr. Severine Atis is a postdoctoral fellow in the physics department at the University of Chicago where she studies self-organization in active fluids in Professor William Irvine's group. She received her PhD from Sorbonne University in Physics where she worked with reaction wave propagation in disordered flows. She joined Professor David Nelson's group at Harvard University as a postdoctoral scholar where she worked on evolutionary dynamics coupled with hydrodynamic flows in collaboration with Professor Andrew Murray in the department of Molecular and Cellular Biology.
Watch "Growing in flows" on YouTube
Michaels Rubenstein, Duke University
1pm EST | Remote meeting
2020 Events
Harvard University
Jayson Paulose, University of Oregon
1pm | Remote meeting
"The Science of Indian Culinary Traditions"
7 p.m. | Harvard Webinar
Watch "The Science of Indian Culinary Traditions" on YouTube
"Emulsions and Foams"
2 p.m. | Harvard Webinar
"Viscosity, Pastry and Chocolate"
2 p.m. | Harvard Webinar
Watch "Viscosity, Pastry and Chocolate" on YouTube
"Honorary Book Celebration Lecture"
7 p.m. | Harvard Webinar
Watch "Honorary Book Celebration Lecture" on YouTube
Max Lavrentovich, University of Tennessee
1pm | Remote meeting
"Culinary Ash in Contemporary Native American Cuisine"
7 p.m. | Harvard Webinar
Watch "Culinary Ash in Contemporary Native American Cuisine" on YouTube
"The Equation for Gnocchi"
7 p.m. | Harvard Webinar
Watch "The Equation for Gnocchi" on YouTube
Brandeis University
"Fermenting Brains. A Journey to Mugaritz microworld"
3 p.m. | Harvard Webinar
Ramon Perisé, Director of Fermentation and R&D at Mugaritz, Spain
Watch "Fermenting Brains. A Journey to Mugaritz microworld" on YouTube
"The Science of Sugar"
7 - 8 p.m. | Harvard Webinar
David R. Nelson, Harvard University
1pm | Remote meeting
Rob Ritchie, University of California
1pm | Remote meeting
YouTube recorded Webinar
"A Nose Dive into Kitchen Pyrolysis"
7 - 8 p.m. | Harvard Webinar
Harold McGee, (@Harold_McGee), author of "On Food and Cooking," "Curious Cook," and the forthcoming book "Nose Dive: A Field Guide to the World's Smells."
Watch "A Nose Dive into Kitchen Pyrolysis" on YouTube
Daniel Cohen, Princeton
11am - noon | Remote meeting
Cellular Herding: programming collective cell migration in living tissues using bioelectric cues
Yelena Bernadskaya, NYU11am - noon | Remote meeting
David R. Nelson, Harvard University
9am | Remote meeting
Watch YouTube presentation
Laura Machesky, University of Glasgow
11am - noon | Remote meeting
Mechanosensing and metabolic demands in cancer cell migration
Tim Fessenden, MIT11am - noon | Remote meeting
Jonathan Selinger, Kent State University
1pm | Remote meeting
Ming Guo, MIT
11am - noon | Remote meeting
Biomechanical imaging of cells, extracellular matrix, and cancer invasion in 3D
Nir Gov, Weizmann Institute of ScienceEugene Shakhnovich, Harvard University
1pm | Remote meeting
UMass Amherst
Brown University
Chao Ma, Harvard University
6 - 7:30pm | Pierce Hall, room 209
REU Application Deadline
Thibaut Divoux, MIT
6 - 7:30pm | Pierce Hall, room 209
Jan Frederik Totz, MIT
6 - 7:30pm | Pierce Hall, room 209
Jerome Fung, Ithaca College
11:00 a.m. to 12:00 p.m. | Pierce Hall 209
2019 Events
Harvard University
Special Panel Discussion
7 - 8 p.m. | Science Center Lecture Hall C
Harold McGee, (@Harold_McGee), author of "On Food and Cooking", "Curious Cook"
Dialogue between Science and Cooking at El Celler de Can Roca. Evolution
7 - 8 p.m. | Science Center Lecture Hall C
Heloise Vilaseca, (@heloislois), director of R&D, El Celler de Can Roca, Girona, Spain
Ahmoy Panagiotis, El Celler de Can Roca, Girona, Spain
Perrin E. Schiebel, School of Physics, Georgia Institute of Technology
6 - 7:30pm | Pierce Hall, room 209
Detlef Lohse, University of Twente, Netherlands
6 - 7:30pm | Pierce Hall, room 209
First, I will introduce the audience to the jumping oil droplet—and its sudden death—in a density stratified liquid consisting of water in the bottom and ethanol in the top : After sinking for about a minute, before reaching the equilibrium the droplet suddenly jumps up thanks to the Marangoni forces. This phenomenon repeats about 30-50 times, before the droplet falls dead all the sudden. We explain this phenomenon and explore the phase space where it occurs.
Next, I will focus on the evaporation of multicomponent droplets, for which the richness of phenomena keeps surprising us. I will show and explain several of such phenomena, namely evaporation-triggered segregation thanks to either weak solutal Marangoni flow or thanks to gravitational effects. The dominance of the latter implies that sessile droplets and pending droplets show very different evaporation behavior, even for Bond number << 1. I will also explain the full phase diagram in the Marangoni number vs Rayleigh number phase space, and show where Rayleigh convections rolls prevail, where Marangoni convection rolls prevail, and where they compete.
The research work shown in this talks combines experiments, numerical simulations, and theory. It has been done by and in collaboration with Yanshen Li, Yaxing Li, and Christian Diddens, and many others.
Desserts and Chocolate
7 - 8 p.m. | Science Center Lecture Hall C
Ramon Morató, (@ramonmorato_), Master Chocolatier, author of "Chocolate" and "Four in One"
Federico Toshi, Eindhoven University of Technology
1:30pm | Lyman Hall, room 425
In recent years we[1] have been conducting a number of real-life experiments aimed at providing some answers. We employ 3d depth-sensor cameras to observe the dynamics of millions of pedestrians in a variety of real-life settings: from a small University corridor, to a museum entrance, city festivals, crowded train stations, etc. Our 3d depth-map cameras have allowed us to record pedestrian trajectories with high space and time accuracies while preserving the privacy of single individuals. Thanks to the large acquired datasets we could study fluctuations and not just average behaviours.
To describe our observations, we borrowed and extended mathematical tools ordinarily used in physics. In this talk we will present some of them and we will discuss how the dynamics of single individuals can be modeled in terms of path integrals or stochastic differential equations. We will discuss how to model collisions between individuals, in low density crowds, and how to learn generic space-time patterns. We will also show how machine learning algorithms can be used to accurately extract orientational data from depth-map images and, finally, we will discuss experiments that we conducted in order to investigate the possibility to nudge human crowds via light stimuli.
Alessandro Corbetta, Jasper Meeusen, Chung-min Lee, Roberto Benzi, Federico Toschi
Physics-based modeling and data representation of pairwise interactions among pedestrians Journal Article
Physical Review E, 98 , pp. 062310, 2018.
Alessandro Corbetta; Chung-min Lee; Roberto Benzi; Adrian Muntean; Federico Toschi
Fluctuations around mean walking behaviours in diluted pedestrian flows
Physical Review E, 95 , pp. 032316, 2017.
Masha Kamenetska, Departments of Chemistry and Physics, Boston University
6 - 7:30pm | Pierce Hall, room 209
The Science of New African Cuisine
7 - 8 p.m. | Science Center Lecture Hall C
Presenter: Selassie Atadika (@MidunuGhana), Midunu, Accra, Ghana
Suraj Shankar, Harvard University
6 - 7:30pm | Pierce Hall, room 209
Exploring Viscosity with Olive Oil and Garum
7 - 8 p.m. | Science Center Lecture Hall C
Pere Planagumà, ROM and Mas de Torrent restaurants, Spain
Irmgard Bischofberger, MIT
6 - 7:30pm | Pierce Hall, room 209
Expanding our work to more complex fluids, dense suspensions, that exhibit both shear-thickening and shear-jamming behavior as a response to an applied stress allows us to probe transitions from flow instabilities to fracture instabilities. Displacing a cornstarch suspension by a pressure-controlled injection of air, we observe a variety of patterns: smooth fingering in the fluid regime and different modes of fractures, ranging from slow branched cracks to single fast fractures. We discuss strategies to predict and control these different failure modes in dense suspensions.
Exploring Heat Transfer in Bolivian Haute Cuisine
7 - 8 p.m. | Science Center Lecture Hall C
Natalie Del Carpio, Gustu, La Paz, Bolivia
Philippe Coussot, Université Paris-Est, Paris, France
6 - 7:30pm | Pierce Hall, room 209
We demonstrate this from Synchrotron and MRI observation in hardwoods, which exhibit a relatively simple hydraulic structure. Capillary imbibition dynamics appears to be dramatically damped (velocity decreased by several orders of magnitude), but the liquid can still climb over significant heights (in contradiction with its dynamics) as soon as sufficient bound water has been adsorbed. This contradiction is confirmed by 3D Synchrotron images of the internal structure obtained during imbibition, which show that the liquid-air interfaces in the capillary vessels remain planar, which implies negligible Laplace pressure, but significantly advance along the vessels, again unexpectedly.
From MRI measurements allowing to distinguish bound and free water, but also direct measurements of the induced macroscopic deformation distribution in time, we then show that this contradiction is explained by the adsorption of a slight amount of bound water in the capillary walls. This adsorption governs the process: it momentarily damps wetting and then allows further advance later when the walls are saturated with bound water. The generality of the process for hygroscopic systems is demonstrated with a model material, i.e. hydrogel, from which both the position and shape evolution of liquid-air interface and the adsorption and propagation of bound water may be directly observed (see below). This suggests the development of bio-inspired porous materials able to absorb liquid with a tunable timing, for pharmaceutical or chemical engineering applications.
We finally discuss the opposite process, i.e. liquid transfers in hardwood structures during drying, as observed from MRI and Synchrotron imaging, and in particular show the essential role of bound water.
Hominy and Posole: The Science of Native American Cooking
7 - 8 p.m. | Science Center Lecture Hall C
Presenter: Freddy Bitsoie (@chef_fjbits), FJBits Concepts, 2013 winner of the Native Chef Competition at the Smithsonian's National Museum of the American Indian
Mehran Kardar, Department of Physics, MIT
6 - 7:30pm | Pierce Hall, room 209
Tom Mason, Department of Physics & Astronomy and Department of Chemistry & Biochemistry, UCLA
6 - 7:30pm | Pierce Hall, room 209
Your World, Your Imagination
7 - 8 p.m. | Science Center Lecture Hall C
Presenter: Janice Wong (@janicewong2am), Asia's Best Pastry Chef 2013 and 2014, Founder 2am: Dessert Bar, Singapore
Kota Shiba, Harvard University & Waseda University, Tokyo
6 - 7:30pm | Pierce Hall, room 209
Exploring Flavor Space: Innovation through Tradition in Noma's Fermentation Lab
7 - 8 p.m. | Science Center Lecture Hall C
Jason White
Brandeis University
Colm Kelleher, Harvard University
6 - 7:30pm | Pierce Hall, room 209
The Science of Sugar
7 - 8 p.m. | Science Center Lecture Hall C
10 Year Anniversary Lecture
7 - 8 p.m. | Science Center Lecture Hall C
Harold McGee (@Harold_McGee), author of "On Food and Cooking", "Curious Cook"
Tzer Han Tan, MIT
6 - 7:30pm | Pierce Hall, room 209
Tzer Han Tan, MIT
6 - 7:30pm | Pierce Hall, room 209
Iain Clark, UCSF and Brigham and Women's Hospital
6 - 7:30pm | Pierce Hall, room 209
Daniel Needleman, Department of Molecular and Cell Biology, SEAS Harvard University
6 - 7:30pm | Pierce Hall, room 209
Michael Norton, School of Physics, Brandeis University
6 - 7:30pm | Pierce Hall, room 209
Philippe Bourrianne, Mechanical Engineering, MIT
6 - 7:30pm | Pierce Hall, room 209
Stephen DeCamp, Harvard Medical School
6 - 7:30pm | Pierce Hall, room 209
David Weitz, Harvard University
6 - 7pm | Maxwell Dworkin 119
Professor Weitz will talk about the relationship between scientific innovation and commercialization, and will describe different routes to entrepreneurship based on his experience in creating and advising biotech and materials startup companies He will also answer student questions on when and how to create or work for a start up company.
Professor Weitz received his B Sc In Physics from the University of Waterloo and his PhD from Harvard University He worked as research physicist for 18 years at Exxon, leading the Interfaces and Inhomogeneous Materials group and Complex Fluids area Prior to joining Harvard, he was Professor of Physics at University of Pennsylvania.
Adel Djellouli, Harvard University
6 - 7:30pm | Pierce Hall, room 209
Gianluca Etienne, EPFL, Lausanne, Switzerland
6 - 7:30pm | Pierce Hall, room 209
Kirk Mutafopoulos, Harvard University and Cytonome
6 - 7:30pm | Pierce Hall, room 209
UMass Boston | 8:00am - 4:45pm
Jose Bico, ESPCI, Paris, France
6 - 7:30pm | Pierce Hall, room 209
Daniel Harris, Brown University, School of Engineering
6 - 7:30pm | Pierce Hall, room 209
In the first part, we investigate the friction experienced by a capillary disk sliding along the interface. We demonstrate that the motion is dominated by skin friction due to the viscous boundary layer that forms in the fluid beneath the moving body. We develop a simple model that considers the boundary layer as quasi-steady, and that is able to capture the experimental behavior for a range of disk radii, masses, and fluid viscosities.
In the second part, we present direct measurements of the attractive force between capillary disks. It is well known that objects at a fluid interface may interact due to the mutual deformation they induce on the free surface, however very few direct measurements of such forces have been reported. In the present work, we characterize how the attraction force depends on the disk radius, mass, and relative spacing. The magnitudes of the measured forces are rationalized with a simple scaling argument and compared directly to numerical predictions.
Future directions in this area will also be discussed, in particular, we are beginning to investigate the motion and interactions of "active" capillary disks at the interface.
Hyunmin Yi, Tufts University, Department of Chemical and Biological Engineering
6 - 7:30pm | Pierce Hall, room 209
Polymeric hydrogels offer attractive platforms for a large range of applications including bioassays, separation and catalysis. We exploit simple photo-induced radical polymerization of poly(ethylene glycol) diacrylate and related materials to capture the as-prepared viral-nanoparticle complexes for facile catalytic reaction applications via replica molding and interfacially initiated hydrogel layer synthesis. This simple, robust and readily tunable scheme allows the large nanocomplexes to be captured and utilized without aggregation or leakage in a stable fashion while small molecule reactants and products can access the catalytic sites with minimal mass transfer limitation. Combined, our facile synthesis-capture strategy integrates potent viral nanotemplates, high catalytic activity and stability of the small nanocatalysts, and robust polymerization schemes. We thus believe that our strategy can be readily extended to programmable manufacturing of a large array of multifunctional materials.
In this presentation, our recent progress on the fabrication of multifunctional membranes via interfacially initiated radical polymerization offering controlled macroporous structures for size-selective protein purification as well as catalytic remediation of toxic compounds will be highlighted.
Lene Oddershede, Niels Bohr Institute, Denmark
3pm | Pierce Hall, room 209
Mechanical forces and biophysical properties of cells are also vital for the morphogenesis of organs and embryos. However, how mechanical force and biophysical properties specifically contribute to tissue formation is poorly understood, predominantly due to a lack of tools to measure and quantify biomechanical parameters deep within living developing organisms without causing severe physiological damage. Using an adapted version of optical tweezers we quantify cellular viscoelasticity as deep as 100-150 µm within living embryos and demonstrate that liver and foregut morphogenesis in zebrafish entails progenitor populations with varying mechanical properties. Gut progenitors exhibit are more elastic compared to the more viscous neighboring cell populations, indicating that viscoelastic properties influence specific morphogenetic behaviors. The higher elasticity of gut progenitors correlates with an increased cellular concentration of microtubules and may be decisive for organ positioning. This approach opens new possibilities for quantitative in vivo investigation of cell mechanics in biological systems with complex 3D organization, such as embryos, explants or organoids.
Hyunmin Yi, Tufts University, Department of Chemical and Biological Engineering
6 - 7:30pm | Pierce Hall, room 209
Polymeric hydrogels offer attractive platforms for a large range of applications including bioassays, separation and catalysis. We exploit simple photo-induced radical polymerization of poly(ethylene glycol) diacrylate and related materials to capture the as-prepared viral-nanoparticle complexes for facile catalytic reaction applications via replica molding and interfacially initiated hydrogel layer synthesis. This simple, robust and readily tunable scheme allows the large nanocomplexes to be captured and utilized without aggregation or leakage in a stable fashion while small molecule reactants and products can access the catalytic sites with minimal mass transfer limitation. Combined, our facile synthesis-capture strategy integrates potent viral nanotemplates, high catalytic activity and stability of the small nanocatalysts, and robust polymerization schemes. We thus believe that our strategy can be readily extended to programmable manufacturing of a large array of multifunctional materials.
In this presentation, our recent progress on the fabrication of multifunctional membranes via interfacially initiated radical polymerization offering controlled macroporous structures for size-selective protein purification as well as catalytic remediation of toxic compounds will be highlighted.
Mark Menesses, Boston University, Department of Mechanical Engineering
6 - 7:30pm | Pierce Hall, room 209
For the second half of the talk, I will discuss the fundamental stability of bubbles in volatile liquids. When a bubble arrives at a free surface, we typically expect the film of the bubble cap to thin over some period of time until it ruptures. Traditionally, the drainage of this film has been considered inevitable with evaporation only hastening the film rupture. Here I will present air bubbles at the free surface of liquids which appear to defy traditional drainage rules and can avoid rupture, persisting for hours until dissolution. Using pure, volatile liquids free of any surfactants, we highlight and model a thermocapillary phenomenon in which liquid surrounding the bubble is continuously drawn into the bubble cap, effectively overpowering the drainage effects.
Harvard University
Gaurav Chaudhary, University of Illinois at Urbana-Champaign
10am | Harvard University, Northwest Building Room B150
Ayse Asatekin, Tufts University, Department of Chemical and Biological Engineering
6 - 7:30pm | Pierce Hall, room 209
In one research direction, we aim to understand how zwitterion-containing copolymers self-assemble, and utilize their behavior to develop membranes with improved capabilities. Zwitterions, functional groups with equal numbers of positive and negative charges, strongly resist fouling, defined as performance loss due to the adsorption and adhesion of feed components onto the membrane. They also easily self-assemble due to strong intermolecular interactions. We have developed high flux, fouling resistant, size-selective membranes utilizing the self-assembly of random copolymers of zwitterionic and hydrophobic monomers. The effective membrane pore size or ~1 nm closely matches the size of self-assembled zwitterionic nanodomains. These membranes are exceptionally fouling resistant, showing little to no flux decline during the filtration of a wide range foulants and complete flux recovery with a water rinse.
We also aim to develop membranes that can separate small molecules of similar size based on their chemical properties. For this purpose, we prepared membranes by depositing micelles formed by random copolymers of a highly hydrophobic fluorinated monomer with methacrylic acid on a porous support. The gaps between the micelles act as 1-5 nm nanochannels functionalized with carboxylic acid groups. These membranes show charge-based selectivity between organic molecules. Furthermore, the carboxyl groups can be functionalized to alter the selectivity of the membrane. We used this method to prepare membranes that exhibit aromaticity-based selectivity. We believe these approaches will eventually lead to novel membranes that are capable of new separations and can replace more energy intensive methods such as distillation or extraction.
Ayse Asatekin, Tufts University, Department of Chemical and Biological Engineering
7 - 9:30pm | Sissy K's 4 Commercial Street Boston, MA
Max Bi, Northeastern University, Department of Physics
6 - 7:30pm | Pierce Hall, room 209
Ovijit Chaudhuri, Stanford University, Department of Mechanical Engineering
6 - 7:30pm | Pierce Hall, room 209
Timothy J. White, University of Colorado, Gallogly Professor of Engineering Department of Chemical and Biological Engineering
4:30 - 5:30pm | Pierce Hall, room 209
It has been long-known that liquid crystallinity in polymers enables exceptional characteristics in high performance applications such as transparent armor or bulletproof vests.
This talk will generally focus on a specific class of liquid crystalline polymeric materials: liquid crystalline elastomers. These materials were predicted by de Gennes to have exceptional promise as artificial muscles, owing to the unique assimilation of anisotropy and elasticity.
Subsequent experimental studies have confirmed the salient features of these materials, with respect to other forms of stimuli-responsive soft matter, are large stroke actuation up to 400% as well "soft elasticity" (stretch at minimal stress).
This presentation will survey our efforts in directing the self-assembly of these materials to realize distinctive functional behavior with implications to soft robotics, flexible electronics, and biology. Most notably, enabled by the chemistries and processing methods developed in my laboratories, we have prepared liquid crystal elastomers with distinctive actuation and mechanical properties realizing nearly 20 J/kg work capacities in homogenous material compositions.
Local control of orientation dictates nonuniformity in the elastic properties, which we recently have shown could be a powerful means of ruggedizing flexible electronic devices. Facile preparation of optical films, prepared with the cholesteric phase, capable of concurrent shape and color change will also be discussed.
In addition, there will be an Industrial Forum Luncheon hosted by Sigma-Aldrich in Pierce 209 at noon, sandwiches and refreshments from Flour Bakery will be provided. This lecture will be a wonderful opportunity to hear more about industrial career opportunities.
Representatives from Sigma-Aldrich will include:
Beth Rosenberg is the Manager of Research Technology Specialist (RTS)-North America. She leads a team of Chemistry, Materials Science and Life Science RTS whose mission is deepen scientific relationship.
Na Li is the Global Product Manager for Electronic Materials at MilliporeSigma.
Tyler Gravelle is the Harvard MilliporeSigma representative and his been working with campus researchers for the past two years.
Herbert Levine, Northeastern University, Department of Physics
4pm | Maxwell Dworkin G115
This talk will focus on the accumulating evidence for this revised perspective, the role of biological physics theory in instigating this whole line of investigation, and on open questions currently under investigation.
Keith Brown, Boston University, Department of Mechanical Engineering
6 - 7:30pm | Pierce Hall, room 209
David Brückner, Arnold Sommerfeld Center for Theoretical Physics, LMU Munich
6 - 7:30pm | Pierce Hall, room 209
Melissa Rinaldin, Instituut-Lorentz for Theoretical Physics, Leiden Institute of Physics, Leiden, NL
6 - 7:30pm | Pierce Hall, room 209
Tim Atherton, Tufts University, Department of Physics and Astronomy
6 - 7:30pm | Pierce Hall, room 209
Behrouz Abedian, Tufts University, Department of Mechanical Engineering
6 - 7:30pm | Pierce Hall, room 209
We consider solid spherical particles that are interacting both locally and globally, and form a single effective ordered or unordered structure in the mixture when viscosity is the dominant dissipation mechanism. It is demonstrated that this assumption is sufficient to predicting stress components of the mixture response to an applied shear stress under different conditions, for both colloidal and non-colloidal suspensions, up to but not including the jamming limit. We'll show that our analysis is consistent with the light-scattering observations of Ackerson group in the past decades. For non-colloidal mixtures, both viscosity and the 2nd-particle pressure data confirm the first Ackerson transition at particle volume fractions 45-50%. For colloidal suspensions, the observed non-Newtonian effects such as shear thinning at higher volume fractions or at higher shear-rates coincide with emergence of the second Ackerson transition to a higher-order crystalline state by the shear flow.
Northeastern University | 8am - 5pm