Calendar of MRSEC Events

Abstract: Understanding and controlling the statistical properties of turbulent flows remains a central challenge in physics, particularly because turbulence rapidly tends toward a locally homogeneous and isotropic state at small scales, limiting our ability to design or manipulate it. We explore a strategy based on “smart” magnetic particles that both probe and actively force turbulence at its smallest scales through externally controlled magnetic fields. Using a combination of experiments, theory, and simulations, we show that particles of different densities, sampling regions with distinct vorticity statistics, experience a rich interplay between magnetic torque and hydrodynamic stresses, enabling targeted modification of small-scale dynamics. Building on recent work on turbulence with odd viscosity [1] and on linearly [2] and angularly forced particles, we demonstrate that turbulent fluctuations can act as an effective noise source that enhances the rotational response of particles, leading to a clear stochastic resonance when the applied rotating magnetic field matches the characteristic intensity of small-scale turbulent vortices [3]. We further uncover a symmetry-breaking mechanism whereby an oscillating magnetic field with zero mean angular velocity induces a net particle rotation even in zero-mean vorticity turbulence [3]. Together, these results could open a route to “designing” turbulence via small-scale forcing with smart particles and establish a magnetic resonance-based approach to measure otherwise inaccessible turbulent vorticity through the detectable magnetic fields emitted by the particles.

Reference:
[1] de Wit, X. M., Fruchart, M., Khain, T., Toschi, F., and Vitelli, V. (2024). Pattern formation by turbulent cascades. Nature, 627(8004), 515-521.
[2] Wang, Z., de Wit, X.M., and Toschi, F. (2024) Localization–delocalization transition for light particles in turbulence, Proc. Natl. Acad. Sci. U.S.A. 121 (38).
[3] Wang, Z., de Wit, X. M., Benzi, R., Wu, C., Kunnen, R. P., Clercx, H. J., and Toschi, F. (2025). Stochastic resonance of rotating particles in turbulence. Nature Communications, 16(1), 10376.

More about the Soft Condensed Matter Seminar

Abstract: How many distinct scale-invariant structures can an intelligent swarm exhibit? Surprisingly, more than ten and counting! By modulating the behavioural rules of motile agents that interact only with their local neighbours, swarms can self-organise into a rich spectrum of scale-invariant spatiotemporal patterns. These emergent collective states correspond to distinct phases and critical phenomena, many of which can be systematically characterised using perturbative and nonperturbative renormalization group (RG) methods. In this talk, I will first provide a concise overview of these universality classes and the underlying mechanisms that generate them. I will then present additional forms of critical behaviour predicted from linear stability analyses [1], highlighting how simple local interaction rules can give rise to an unexpectedly diverse landscape of scale-invariant collective dynamics.

Reference: [1] P Jentsch, CF Lee, Diversity of critical phenomena in the ordered phase of polar active fluids. ArXiv:2512.18846

More about the Soft Condensed Matter Seminar

Abstract: While we all got used to seeing cell cytoplasm and nucleoplasm as crowded micro-environments, it remains unknown how intracellular density distributions emerge and affect cellular physiology. Here, we show that nuclear and cytosolic compartments across living systems establish a conserved density ratio due to a pressure balance across the nuclear envelope. Nuclear export and import create a specific nuclear proteome that exerts a colloid osmotic pressure, which, assisted by chromatin entropic pressure, "inflates" the nucleus to its preferred density and volume. We show how this density distribution emerges during formation of nuclei in Xenopus egg extract system. By means of a simple quantitative model we can predict the dynamics of nuclear growth in the normal setting as well as under multiple biological and biophysical perturbations. In C. elegans development, the nuclear-to-cytoplasmic density ratio is robustly maintained even when nuclear-to-cytoplasmic volume ratios change. We show that loss of density homeostasis correlates with altered cell functions like senescence and propose density distributions as key markers in pathophysiology.

More about the Squishy Physics Seminar

Abstract: Modern machine learning has achieved remarkable success across science and technology, while continuing to call for a precise theoretical understanding of how and why these systems work. In this talk, I will show how techniques from statistical physics can be used to derive a low-dimensional description of the training dynamics through a small set of order parameters in prototypical learning problems. I will discuss how different sources of algorithmic noise affect performance, and how optimal control of the order-parameter dynamics can be used to design efficient training protocols.

More about the Soft Condensed Matter Seminar

Abstract: Nonequilibrium systems are ubiquitous, from swarms of living organisms to machine learning algorithms. While much of statistical physics has focused on predicting emergent behavior from microscopic rules, a growing question is the inverse problem: how can we guide a nonequilibrium system toward a desired state? This challenge becomes particularly daunting in high-dimensional or complex systems, where classical control approaches often break down. In this talk, I will integrate methods from optimal control theory with techniques from statistical physics to tackle this problem in two broad classes of nonequilibrium systems: active matter, focusing on multimodal strategies in animal navigation and mechanical confinement of active fluids, and learning systems, where I will apply control theory to identify optimal learning principles for neural networks. Together, these approaches point toward a general framework for controlling nonequilibrium dynamics across systems and scales.

More about the Soft Condensed Matter Seminar

Abstract: Recent advances in large-scale scientific datasets are creating new opportunities for machine learning (ML) methods to more effectively capture scientific phenomena with greater accuracy and reach. In this talk, I will discuss how these advances are both shifting ML design paradigms and enabling new scientific inquiries. This includes investigations into understanding if neural networks, and specifically Transformers, can autonomously discover fundamental physical relationships from data, and demonstrating how more flexible machine learning modeling design choices enable capturing physical dynamics across multiple scales. I will also explore how generative modeling approaches grounded in statistical mechanics can be applied to accelerate the sampling of transition pathways, and as a framework to align and bridge the gap between simulated data and experimental observations.

More about the Soft Condensed Matter Seminar

Abstract: Biological systems are inherently asymmetric, arising from chemical isomer specificity that propagates from metabolite chirality to higher-order structure and function, with profound consequences for the development of pharmaceuticals, fragrances, and agrochemicals. Yet, modern isomer analysis relies on slow and resource-intensive chromatography, limiting the deep characterization of biochemical systems. In this seminar, I will present a biology-driven alternative in which bacterial regulatory proteins are repurposed as genetically-encoded biosensors for precise, scalable measurement of chemical isomers. Through directed evolution of malleable protein scaffolds, we generate sensors selective for diverse compounds, including terpenes, polyphenols, alkaloids, and synthetic pharmaceuticals. I will also describe computational strategies that leverage large biological datasets to systematically identify biosensors and engineer enzymes for therapeutic compounds. Finally, I will introduce growth-coupled assays combined with massively parallel sequencing that enable the simultaneous measurement of over 900,000 protein–chemical interactions, generating quantitative data to guide predictive protein engineering. Together, programmable genetic sensors provide a scalable platform for studying and engineering asymmetric biochemical systems with applications spanning diagnostics, biocatalyst development, and drug discovery.

More about the Squishy Physics Seminar

Through the REU program, we provide a coordinated, educational and dynamic research community to inspire and encourage young scientists to continue on to graduate school. We emphasize professional development workshops and seminars for a career in science and engineering. Weekly faculty seminars that highlight research and community activities are integrated into the program.

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GRC Education Requirements: Undergraduates or those who have not obtained a bachelor's degree in science/engineering (or acceptable equivalent) are not eligible to apply to attend Gordon Research Conferences or Seminars.

Conference Description: The Colloidal, Macromolecular and Polyelectrolyte Solutions GRS provides a unique forum for young doctoral and post-doctoral researchers to present their work, discuss new methods, cutting edge ideas, and pre-published data, as well as to build collaborative relationships with their peers. Experienced mentors and trainee moderators will facilitate active participation in scientific discussion to allow all attendees to be engaged participants rather than spectators.

This meeting will focus on the connection between microstructure and macroscopic properties of complex fluids, highlighting approaches for characterizing and designing functional materials. Discussions will cover experimental and computational methods, as well as practical applications. Graduate students and post-doctoral researchers working in these areas are encouraged to apply and take part in this interactive and collaborative scientific exchange.

Application Information: Applications for this meeting must be submitted by January 3, 2026. Please apply early, as some meetings become oversubscribed (full) before this deadline. If the meeting is oversubscribed, it will be stated here. Note: Applications for oversubscribed meetings will only be considered by the conference chair if more seats become available due to cancellations.

More about the Bridging Microstructure and Functionality Seminar

Related Meeting: This GRC will be held in conjunction with the "Science of Soft Building Blocks for Functional Materials" Gordon Research Seminar (GRS) on February 1 - 6, 2026.

Related Meeting Description: Dispersions and solutions of colloids, macromolecules, or polyelectrolytes enable the development of functional materials for societally critical applications such as energy production and storage, controlled release, biomaterials, and environmental remediation. This GRC will feature talks that address exciting open questions in the fundamental science controlling the structure, dynamics, and emergent properties of these soft building blocks; the active, biomimetic, and/or learning processes by which they assemble in and out of equilibrium; and their use in advanced applications.

Those interested in attending both meetings must submit an application for the GRS in addition to an application for the GRC. Refer to the associated GRS program page for more information.
Application Information: Applications for this meeting must be submitted by January 4, 2026.

Abstract: Shape-programmed sheets morph into curved surfaces upon stimulation by light, heat, or chemistry. They are ubiquitous throughout biology, and synthetic versions show great promise as soft large-strain actuators. A central theme is the generation of Gauss curvature (GC) via patterns of in-plane deformation, which imbues the morphed structures with mechanical strength. A canonical example is a pattern of azimuthal contraction that morphs a disk into a cone, which cannot be flattened without energetically costly stretch because its tip bears concentrated GC. In that spirit, I'll demonstrate novel designs for nematic deformation patterns that encode concentrated GC at generalized "tips" (via topological defects), along ridges (via seams between smooth patterns), and within the central holes of annuli (via spirals). Then, to investigate mechanical strength quantitatively, we’ll turn to the load-bearing capacity of perfect conical shells. This classical-sounding problem is in fact rather subtle; I will present a boundary-layer solution, leading to an asymptotic critical force that scales like thickness to the 5/2—a surprising and novel scaling that has broad implications for shell buckling. Finally, I’ll discuss nematic shape-morphers in which both the magnitude and direction of deformation are varied spatially, exemplified by liquid crystal elastomers under patterned illumination. In this emerging paradigm, a single physical sheet can be morphed into infinitely many target surfaces, opening the door to precise shape adjustments, new functionalities, and designable non-reciprocal loops in shape space.

More about the Soft Condensed Matter Seminar