Description:

Weekly seminars with guest speakers.

Thursdays 9:00AM - 10:00AM Tech M345

Hang Lu
Georgia Tech
Host: Luis Amaral

A Chemical Engineering’s Approach to Systems Biology - Microfluidics, Automation, and Big-Data

My lab is interested in engineering micro systems and automation tools to address questions in systems neuroscience, developmental biology, and cell biology that are difficult to answer with conventional techniques. Micro technologies provide the appropriate length scale for investigating molecules, cells, and small organisms; moreover, one can also take advantage of unique phenomena associated with small-scale flow and field effects, as well as unprecedented parallelization and automation to gather quantitative and large-scale data about complex biological systems.  I will show how continuous flow, multi-phase flow, and open microfluidic systems can be used to culture, manipulate, image, and stimulate samples.  I will show how image informatics and statistical machine learning techniques can greatly enhance our ability to understand the information carried in images and video microscopy data. We apply these techniques to address a variety of questions in developmental and behavioral neurogenetics, and aging in a soil nematode C. elegans, which have implications in human developmental, psychiatric, and age-related neural disorders.  

Hang Lu is the Love Family Professor in the School of Chemical and Biomolecular Engineering and the Director of the Interdisciplinary Bioengineering Program at Georgia Tech.  She graduated summa cum laude from the University of Illinois at Urbana-Champaign in 1998 with a B.S. in Chemical Engineering.  She has a Master’s degree in Chemical Engineering Practice from MIT (2000).  She obtained her Ph.D. in Chemical Engineering in 2003 from MIT.  Between 2003 and 2005, she was a postdoc at UCSF and the Rockefeller University in neuroscience.  Her current research interests are in microfluidics, automation, quantitative analyses, and their applications in neurobiology, cell biology, cancer, and biotechnology.  Her award and honors include the Pioneer of Miniaturization Lectureship, the ACS Analytical Chemistry Young Innovator Award, a National Science Foundation CAREER award, an Alfred P. Sloan Foundation Research Fellowship, a DuPont Young Professor Award, a DARPA Young Faculty Award, Council of Systems Biology in Boston (CSB2) Prize in Systems Biology, Georgia Tech Junior Faculty Teaching Excellence Award, and Georgia Tech Outstanding PhD Thesis Advisor Award; she was also named an MIT Technology Review TR35 top innovator, and invited to give the Rensselaer Polytechnic Institute Van Ness Award Lectures in 2011, and the Saville Lecture at Princeton in 2013.  She is an elected fellow of American Association for the Advancement of Science (AAAS) and an elected fellow of the American Institute for Medical and Biological Engineering (AIMBE). She is currently the associate director of the Southeast Center for Mathematics and Biology (SCMB) at Georgia Tech, supported by NSF and Simons Foundation.  Her lab’s work has been and is supported by >$30M ($15M to her lab) from US NSF, NIH, private foundations and others.

Description:

Weekly seminars with guest speakers.

Thursdays 9:00AM - 10:00AM Tech M345

Thomas Russell
UMass Amherst
Host: Mitchell Wang

Structuring Liquids

The ability to manipulate and lock-in the shape of one liquid in a second, i.e structuring the liquids, allows the generation of unique materials that have the dynamics and mobility of liquids but the structural integrity of a solid. Bicontinuous fluids for separations, novel encapsulants for delivery systems, or all-liquid charge transport systems ae possible. Yet, these fluids have shapes that are far removed from their equilibrium shape and developing routes to kinetically lock-in these non-equilibrium shapes while retaining the local fluidity is key. We describe the in situ generation of nanoparticle surfactants in oil/water systems that assemble at the liquid/liquid interface.  When the liquids are brought into non-equilibrium shapes, the nanoparticle surfactants will jam at the interface, freezing in the shapes of the liquids.  External stimuli, as for example pH, electric or magnetic fields, or temperature can then be used to re-shape the liquids, so that the structured liquids are adaptive. For water/water systems, the formation of a coacervate membrane that lead to aqueous compartmentalized systems separated by membranes with directed charge transport.  This enables the design of coordinated and cascading reaction schemes similar to those seen in biological systems. 

Thomas P. Russell, the Silvio O. Conte Distinguished Professor of Polymer Science and Engineering at the University of Massachusetts in Amherst, received his PhD in 1979 in Polymer Science and Engineering from the University of Massachusetts Amherst, a Research Associate at the University of Mainz (1979-1981), a Research Staff Member at the IBM Almaden Research Center in San Jose, CA (1981-96). He is also a Visiting Faculty at the Materials Science Division in the Lawrence Berkeley National Laboratory, an Adjunct Professor at the Beijing University of Chemical Technology, and a PI at the Advanced Institute of Materials Research at Tohoku University.  His research interests include the surface and interfacial properties of polymers, phase transitions in polymers, directed self-assembly processes, the use of polymers as scaffolds and templates for the generation of nanoscopic structures, the interfacial assembly of nanoparticles and wrinkling of thin polymer films.  He was the Director of the Materials Research Science and Engineering Center from (1996-2009), Director of the Energy Frontier Research Center on Polymer-Based Materials for Harvesting Solar Energy (2009-2014), a PI in the Global Research Laboratory at Seoul National University (2005-2015), and the Beijing Advanced Innovation Center on Soft Matter (2016-present). He has over 850 publications, 35 patents and edited 5 books. He is a Fellow of the American Physical Society, Materials Research Society, Neutron Scattering Society of America, American Association for the Advancement of Science, and the American Chemical Society, Polymer Materials Science and Engineering Division.  He has received the Polymer Physic Prize of the APS, the Cooperative Research Award of the ACS, the Dutch Polymer Award, the ACS Award in Applied Polymer Science, Society of Polymer Science Japan International Award, and is an elected member of the National Academy of Engineering and the National Academy of Inventors.

Description:

Weekly seminars with guest speakers.

Thursdays 9:00AM - 10:00AM Tech M345

Juan de Pablo (Mah Lecture)
UChicago
Host: Randy Snurr
Additional lecture and reception held on October 16th

Soft matter design and characterization in the era of machine learning
Wednesday October 16th 

Advances in molecular modeling algorithms, optimization strategies, and machine learning techniques, are ushering a new era of materials science and engineering in which computational tools are routinely used to probe, design, and interrogate matter and functional materials systems. The way in which problems and questions are formulated is rapidly changing, and it is important to rethink the role of research scientists and engineers in the context of these advances. In this presentation I will illustrate some of these ideas by relying on a variety of examples taken from chemical engineering, physics, biology and materials science. In the first, I will discuss the coupling of experiments and molecular models, and how that coupling can be used to extract additional information from experiments that would otherwise be difficult to generate. In the second I will present models of biological systems – DNA and chromatin - that use machine learning to integrate experimental and computational information form a wide range of sources, and explain how the resulting information can be used to address important questions in epigenetics. In the third, I will discuss how evolutionary optimization and machine learning can be used to create new mechanical metamaterials with useful and unusual mechanical properties.

Liquid crystals – from simple self-assembling systems, to autonomous materials constructs
Thursday, October 17th 

Polymeric materials that comprise mechano-chemically active components are able to undergo spontaneous structural rearrangements that generate internal stresses and motion. These stresses can be particularly large in the case of liquid crystalline polymers, where elasticity becomes important. At intermediate to high concentrations, such materials form nematic phases that are riddled with defects that serve as attractors for solutes or colloidal particles. As such, defects can also be used for directed self-assembly. Going beyond passive nematic systems, introducing internal activity leads to the emergence of new structural and dynamical features that are not found in materials at rest.  Understanding how specific behaviors arise in active liquid crystals is important for design of autonomous materials systems capable of delivering desired functionalities, including the possibility of transporting colloidal particles in a programable manner. This lecture will focus on the relationship between structure, activity, and motion in lyotropic liquid crystalline polymeric systems that include colloidal particles. More specifically, results will be presented for actin and tubulin suspensions, where activity is generated by protein motors. A distinctive feature of these biopolymers is that characteristic contour lengths can range from hundreds of nanometers to tens of microns, thereby making them amenable for study by optical microscopy. By relying on molecular and meso-scale models, it is possible to arrive at a comprehensive description of these suspensions that helps explain the connections between molecular structure, the formation and shape of distinct topological defects, the localization of particles in such defects, activity, and defect dynamics. One of the outcomes of such a description is the realization that hydrodynamic interactions can in some cases exacerbate or mitigate the elasticity of the underlying materials, leading to non-intuitive phenomena that do not arise at equilibrium. These findings raise the prospect that, by balancing such effects, it might be possible to design functional materials where specific, autonomous macroscopic dynamical responses are programmed into a system to create function.  

Description:

Weekly seminars with guest speakers.

Thursdays 9:00AM - 10:00AM Tech M345

Heather Kulik
MIT
Host: Randy Snurr

Title:
Molecular design blueprints: materials and catalysts from new simulation and machine learning tools

Abstract:
Many compelling functional materials and highly selective catalysts have been discovered that are defined by their metal-organic bonding. The rational design of de novo transition metal complexes however remains challenging. First-principles (i.e., with density functional theory, or DFT) high-throughput screening is a promising approach but is hampered by high computational cost, particularly in the brute force screening of large numbers of ligand and metal combinations. In this talk, I will outline our efforts over the past few years to accelerate the design of inorganic complexes for catalysis and materials science: i) We have automated and simplified simulation, eliminating the need for tedious manual preparation of computational chemistry calculations, ii) We developed machine learning (ML) models that predict properties in a fraction of the time of traditional calculations, iii) We developed ML models that can predict outcomes of simulations for dynamic, autonomous control, and iv) We integrated these tools into an automated design workflow for the evolutionary algorithm optimization of materials properties with awareness of ML model and DFT model uncertainty. I will describe how this powerful toolkit has advanced our understanding of a range of metal-organic complexes from functional spin crossover materials to open-shell transition metal catalysts by enabling the rapid screening of thousands of candidate molecules and by revealing robust design rules.

Bio:
Professor Heather J. Kulik is an Associate Professor in the Department of Chemical Engineering at MIT. She received her B.E. in Chemical Engineering from the Cooper Union for the Advancement of Science and Art in 2004 and her Ph.D. from the Department of Materials Science and Engineering at MIT in 2009. She completed postdoctoral training at Lawrence Livermore and Stanford, prior to joining MIT as a faculty member in November 2013. Her research in accelerating computational modeling in inorganic chemistry and catalysis has been recognized by a Burroughs Wellcome Fund Career Award at the Scientific Interface, Office of Naval Research Young Investigator Award, DARPA Young Faculty Award, NSF CAREER Award, the AAAS Marion Milligan Mason Award, and the Journal of Physical Chemistry Lectureship, among other awards.

Description:

Weekly seminars with guest speakers.

Thursdays 9:00AM - 10:00AM Tech M345

Simon Rogers
UIUC
Host: Jeff Richards

Title: A material’s perspective: Developing a transient framework for understanding nonlinear rheological responses

Abstract: Modern society relies on soft materials, which are important for foods, consumer products, biological materials, and energy and environmental applications. The interactions that hold soft materials together are often comparable in magnitude to the thermal energy, making them especially susceptible to weak forces. In order to develop functional soft materials, they need to be processed far from equilibrium. Despite recent progress, we still do not understand how molecular-scale behavior informs macroscopic properties in these systems. Of particular interest is the transient rheology, where stresses and deformations can induce massive molecular reorganizations that manifest as transformations in the macroscopic material properties. Transient conditions are encountered in most biological situations, and well as industrial flows including startup and cessation, which often dictates the success of a product or process.

The overwhelmingly preferred method for probing the viscoelasticity of soft materials is the application of oscillatory shearing, in which a material is sinusoidally deformed. When the amplitude of the shearing is small, the responses elicited are also sinusoidal. These responses are typically decomposed into components in-phase and an out-of-phase with the deformation to obtain the dynamic moduli, G’ and G”. When the experiment is extended to mirror more realistic processing conditions by increasing the amplitude of the deformation, the response of the material being tested becomes non-sinusoidal. There has been a significant effort in the last decade to develop methods capable of providing clear physical insight into nonlinear responses. Many of these schemes, such as Fourier transformation, take linear algebraic approaches and describe an entire period of oscillation in terms of some orthonormal basis. However, the typical phenomenological descriptions of nonlinear responses use the language of sequences of processes, and not linear summations. This is evident in a number of recent studies that have identified features in the nonlinear oscillatory responses of colloidal glasses and gels that are best described from the perspective of the material in terms of elastic deformation followed by yielding, and then stable flow.

In this talk, I will present a new quantitative framework for understanding nonlinear transient rheological responses that is commensurate with the phenomenological studies and physical descriptions. The new approach describes responses in terms of instantaneous measures that are well-defined everywhere. I will show the results of new experiments that are inspired by the new quantitative framework that clearly link molecular-level information to the macroscopic rheology, providing a rational route toward structure-property-processing relationships.

Bio: Simon A. Rogers is an Assistant Professor in the Department of Chemical and Biomolecular Engineering at the University of Illinois at Urbana-Champaign. Dr. Rogers uses experimental and computational tools to understand and model advanced colloidal, polymeric, and self-assembled materials. He joined the department in 2015. He received his BSc in 2001, BSc (Hons) in 2002; and his PhD from Victoria University of Wellington in New Zealand in 2011. He completed his postdoctoral research at the Foundation for Research and Technology in Crete, the Jülich Research Center in Germany, and the Center for Neutron Research at the University of Delaware.