Ye Zhang wins Materials Research Society Poster Award

Ye Zhang, a Postdoctoral Fellow from Prof. Bing Xu’s research group at Brandeis, won the 2012 MRS Fall Meeting Poster Awards for her poster titled Self-oscillatory Hydrogels Driven by Belousov-Zhabotinsky Reaction within the symposium on Bioinspired Directional Surfaces-From Nature to Engineered Textured Surfaces & Precision Polymer Materials-Fabricating Functional Assemblies, Surfaces, Interfaces, and Devices. The goal of the project is to make materials that operate like synthetic cardiac or intestinal muscles; feed them and they will pump forever, or as long as the arteries remain open. Ye, the poster’s lead author, is a member of the Brandeis Materials Research Science and Engineering Center (MRSEC) working on project involving the groups of Profs. Bing Xu, Irving Epstein and Seth Fraden of the Chemistry and Physics Departments.

Ye’s work focuses on the development and study of active matter based on non-linear chemical dynamics, specifically the Belousov-Zhabotinsky reaction. Beginning two years ago she systematically modified a class of gels that exhibit periodic volume oscillations which were produced by other groups. First, Ye succeeded in significantly improving the amplitude of volume oscillations. Next, she developed several novel self-oscillatory systems and established a systematic way to improve the bulk material properties of the synthetic heart.  To build a reliable beating heart, Ye optimized the molecules building the material at the molecular level of tens to hundreds of atoms, or scales of 1 nm and then figured out how to assemble them into networks of polymers on the scales of 10 – 100 nm, and then further assembled them on a longer length scale, into elastic networks on the scales of microns, and finally sculpted the resulting rubbery materials using photolithographic and microfluidic methods into useful shapes for study and application. Ye’s award is a recognition of her contribution to molecular engineering and serves as a quintessential example of the  “bottom-up” construction methods exemplified by the interdisciplinary teams of the Brandeis MRSEC.

Materials in Motion: Engineering Bio-Inspired Motile Matter

Life is on the move! Motion is ubiquitous in biology. From the gargantuan steps of an elephant to the tiniest single celled amoeba, movement in biology is a complex phenomenon that originates at the cellular level and involves the organization and regulation of thousands of proteins. These proteins do everything from mixing the cytoplasm to driving cell motility and cell division. Deciphering the origins of motion is no easy feat and scientists have been studying such complex behavior for quite some time. With biology as an inspiration, studying these complex behaviors provides insight into engineering principals which will allow researchers to develop an entirely new category of far-from-equilibrium materials that spontaneously move, flow or swim.

In a recent report in the journal Nature, a team of researchers from Brandeis University consisting of Tim Sanchez, Daniel T. N. Chen, Stephen J. DeCamp, Michael Heymann, and Zvonimir Dogic have constructed a minimal experimental system for studying far-from-equilibrium materials. This system demonstrates the assembly of a simple mixture of proteins that results in a hierarchy of phenomena. This hierarchy begins with extending bundles of bio-filaments, produces networks that mix themselves, and finally culminates in active liquid crystals that impart self-motility to large emulsion droplets.

Their system consists of three basic components: 1) microtubule filaments, 2) kinesin motor proteins which exert forces between microtubule filaments, and 3) a depletion agent which bundles microtubule filaments together. When put together under well-defined conditions, these components form bundled active networks (BANs) that exhibit large-scale spontaneous motion driven by internally generated active stresses. These motions, in turn, drive coherent fluid flows. These features bear a striking resemblance to a biological process called cytoplasmic streaming, in which the cellular cytoskeleton spontaneously mixes its content. Additionally, the system has great potential for testing active matter theories because the researchers can precisely tune the relevant system parameters, such as ATP and protein concentration.

 

The researchers also demonstrate the utility of this biologically-inspired synthetic system by studying materials science topics that have no direct biological analog. Under dense confinement to an oil-water interface, microtubule bundles undergo a spontaneous transition to an aligned state. Soft matter physics describes such materials as liquid crystals, which are the materials used to make liquid crystal displays (LCDs). These active liquid crystals show a rich variety of dynamical behavior that is totally inaccessible to their equilibrium analogs and opens an avenue for studying an entirely new class of materials with highly desirable properties.

Lastly, inspired by streaming flows that occur in cells, the researchers encapsulate the bundled active networks into spherical emulsion droplets. Within the droplet, microtubules again formed a self-organized nematic liquid crystal at the oil-water interface. When the droplets were partially squished between glass plates, the streaming flows generated by the dynamic liquid crystals lead to the emergence of spontaneous self-motility.

This research constitutes several important advances in the studies of the cytoskeleton, non-equilibrium statistical mechanics, soft-condensed matter, active matter, and the hydrodynamics of fluid mixing. The researchers have demonstrated the use of biological materials to produce biomimetic functions ranging from self-motility to spontaneous fluid flows using fundamentally new mechanisms. Additionally, the experimental system of bundled active microtubules is poised to be a model for exploring the physics of gels, liquid crystals, and emulsions under far-from-equilibrium conditions.

To see more videos from the Dogic lab at Brandeis University, check out their YouTube page.

The best battalion in the National Guard

Gregory Widberg is the Sr. Mechanical Engineer in the Physics department who also works with other departments in the Division of Science repairing scientific equipment.  Greg was called to active duty and served in Afghanistan from 2011 to 2012 as the Command Sgt. Major for the 1st Battalion, 182nd Infantry Regiment.  Greg is shown accepting the Walter T. Kerwin Jr. Readiness Award in a ceremony in Washington, DC on October 23, 2012.  The award is presented to the battalion with the highest level of readiness in its respective component.

General Raymond Odierno, chief of staff, U. S. Army, Lt Col. Ron Cupples, commander, 1st Battalion, 182nd Infantry Regiment, Massachusetts Army National Guard, Command Sgt. Maj. Greg Widberg, senior enlisted advisor, 1st Battalion, 182nd Infantry Regiment, Massachusetts Army National Guard, and Command Sgt. Maj. Raymond Chandler III, Sgt. Maj. of the Army, pose for a picture after Odinero presented the Walter T.Kerwin Jr. Readiness Award to Cupples and Widberg during a ceremony at the Association of the United States Army Eisenhower Luncheon as the Walter E. Washington Convention Center, Washington D.C., Oct. 23, 2012. The Kerwin Award, which is open to Army National Guard and Army Reserve battalions, is presented to the battalion with the highest level of readiness in it’s respective component. In order to be considered each battalion must have been rated as having superior performance in eight specific areas as well as meeting other specific criteria. (U.S. Army photo by Staff Sgt. Jerry Saslav, Massachusetts National Guard Public Affairs)

New England Complex Fluids Workshop at Brandeis Sept 21

The 52nd New England Complex Fluids Workshop will be held on September 21, 2012. hosted by the Brandeis MRSEC. The workshop will feature a panel of researchers from industry exploring the academic / industrial relationship. Additionally, we will have one session of invited academic speakers, plus  two contributed “sound bite” sessions. Please consider submitting your work for an oral presentation.

In addition to taking questions from the floor, the panel will address questions such as  what kind of training and education do industrial labs seek in job applicants? What (scientific) knowledge should applicants possess? experience? skills? creativity? business knowledge? What should the universities do to better prepare students for a career in industry? What opinion do the industrial scientists and managers have on the research being done at universities? And how does research done in industry compare to that done in universities?  How common are collaborations between industry and academic researchers? What makes a successful collaboration? When does industry use academic consultants?

Registration (free) required: http://complexfluids.org/ (deadline: 8am, September 19, 2012)

SCHEDULE

 Registration & Coffee9:00 – 9:30 AM Shapiro Campus Center, Room 236.1 Talk9:30 PM – 10:10 AM  (30 mins + 10 disc)
Shapiro Campus Center Theater

Michael Aizenberg, Wyss Institute, Harvard
     Responsive Gel-Based Dynamic Materials

Sound Bites10:15 AM – 11 AM
Shapiro Campus Center Theater
            Five minute updates of current research

Coffee11:00 AM – 11:30 AM
Shapiro Center, Room 236

Panel11:30 – 1:00 PM 
Shapiro Center, Room 236
Industry / Academic relations
Rick Jacubinas (BASF), Darren Link (Raindance), Ian Morrison (Harvard)
Chris Harrison (Schlumberger), Patrick Spicer (Procter & Gamble)

Lunch1:00 – 2:00 PM
 Shapiro Center, Room 236

1 Talk2:00 PM – 2:40 PM  (30 mins + 10 disc)
Shapiro Campus Center Theater
Shekhar Garde, Chem & Bio Eng, Rensselaer Polytechnic Institute
Hydration Phenomena at the Interface of Physics and Biology


Sound Bites: 2:45 PM – 4:00 PM
Shapiro Campus Center Theater
            Five minute updates of current research

Coffee4:00 PM – 4:30 PM
Shapiro Center, Room 236

Baskaran Wins NSF-CAREER award to pursue research on active fluids

Dr. Aparna Baskaran of the Physics Department has been awarded the prestigious CAREER grant from the National Science Foundation that is a highly competitive development grant for early career tenure track faculty members. This grant will fund the research ongoing in Dr. Baskaran’s group on dynamics in active materials. Active materials are a novel class of complex fluids that are driven out of equilibrium at the level of individual entities. Examples of such systems include bacterial suspensions, cytoskeletal filaments interacting with motor proteins and inanimate systems such as self-propelled phoretic colloidal particles. The theoretical challenge in understanding these systems lies in the fact that, unlike traditional materials, we no longer have the scaffold of equilibrium on which to base the theoretical framework.  At the practical front, these materials exhibit novel properties not seen in regular materials.  Further, they form the physical framework of biological systems  in that regulatory mechanisms modulate the mechanical properties of this material in response to environmental stimuli.  Dr. Baskaran’s research in this field will be done in collaboration with the groups of Dr. Michael Hagan, Dr. Zvonimir Dogic and Dr. Bulbul Chakraborty. It will enhance and complement the MRSEC research activities in the active materials thrust.

Figure Caption : Videos of example systems for active materials. A) A fish school exhibiting complex collective swimming. B) Swarming at the edge of an E. Coli Bacterial Colony. C) Cytoplasmic streaming inside the yolk of a fertilized cell.

LHC announcement of new particle that could be the Higgs Boson

Today at CERN joint seminars were given by the two major experiments (ATLAS and CMS) at the Large Hadron Collider (LHC) in which they announced the observation of a new particle that could be the Higgs Boson. The mass of this particle is 126 GeV, roughly that of a Barium atom. The level of statistical significance of the new particle is five standard deviations, which is general considered the threshold level of observation needed to make a claim of discovery. Higgs Boson has been long sought to complete the Standard Model of Particle Physics. The Brandeis High Energy Physics Group, along with many colleagues from around the world, has been working for the last 18 years designing, building, commissioning, running and analyzing data from the ATLAS experiment (at CERN).

The Standard Model of Particle Physics is our best understanding of the laws of nature that govern the behavior of all the things in the universe that we can see. One outstanding question in this theory has been: “where does mass come from?”. One proposed solution to this problem (by Peter Higgs) was the addition a field to our picture of the universe that adds a drag on each particle, different for each kind of particle, which we interpret as inertia or mass. This theory predicts a new particle, the Higgs Boson. Finding this particle is considered proof of this version of the standard model. One comment on “physics speak”, a particle being “consistent with the Higgs Boson” is not the same as “discovery of the Higgs Boson”. The predicted properties of this particle are very specific and much more work needs to be done to establish the exact nature of this new object. Is it the object that completes that Standard Model or is it a slightly different object that will point to a new direction in the understanding of nature? This question will be hotly pursued in the future running of the experiments.

On a local note, in a more technical vein; one of the two decay modes that were used by the ATLAS experiment to look for the Higgs Boson decays into four leptons, either four muons or four electrons or two of each. The electron and muon being two of the three leptons (meaning these particles don’t participate in the strong or nuclear force) of the Standard Model. The Brandeis HEP group has been instrumental in the design, construction and operation of the system that identifies and measures muons produced in the collisions at the LHC.

Jim Bensinger
July 4, 2012

editor’s note: see also interview at Brandeis NOW

Video Poster: One Dimensional Rings of Coupled Oscillators

Brandeis Physics grad students (IGERT trainees) Michael Giver and Nathan Tompkins have a “video poster” in the NSF IGERT Video & Poster Competition on “One Dimensional Rings of Coupled Oscillators – Turing’s Theory Realized”. You can check out and comment on their poster on-line at http://posterhall.org/igert2012/posters/244.

award ribbonUpdate: Michael and Nathan’s poster received a Judge’s Choice award ($2,000.00) in the competition!

Six scientists secure fellowships

One current undergraduate, and five alumni, from the Brandeis Sciences were honored with offers of National Science Foundation Graduate Research Fellowships in 2012. The fellowships, which are awarded based on a national competition, provide three full years of support for Ph.D. research and are highly valued by students and institutions. These students are:

  • Samuel McCandlish ’12 (Physics) , a current student who did research with Michael Hagan and Aparna Baskaran, resulting in a paper “Spontaneous segregation of self-propelled particles with different motilities” in Soft Matter (as a junior). He then switched to work with Albion Lawrence for his senior thesis research. Sam will speak about “Bending and Breaking Time Contours: a World Line Approach to Quantum Field Theory” at the Berko Symposium on May 14.  Sam has been offered a couple of other fellowships as well, so he’ll have a nice choice to make. Sam will be heading to Stanford in the fall to continue his studies in theoretical physics.
  • Briana Abrahms ’08 (Physics). After graduating from Brandeis, Briana followed her interests in ecological and conversation issues, and  in Africa as a research assistant with the Botswana Predator Conservation Trust, Briana previously described some of her experiences here in “Three Leopards and a Shower“. Briana plans to pursue as Ph.D. in Ecology at UC Davis.
  • Sarah Robinson ’07 (Chemistry). Sarah did undergraduate research with Irving Epstein on “Pattern formation in a coupled layer reaction-diffusion system”. After graduating, Sarah spent time with the Peace Corps in Tanzania, returning to study Neurosciene at UCSF.
  • Si Hui Pan ’10 (Physics) participated in a summer REU program at Harvard, and continued doing her honors thesis in collaboration with the labs at Harvard. Her award is to study condensed matter physics at MIT.
  • Elizabeth Setren ’10 was a Mathematics and Economics double major who worked together with Donald Shepard (Heller School) on the cost of hunger in the US. She has worked as an Assistant Economist at the Federal Reserve Bank of New York and her award is to study Economics at Harvard.
  • Michael Ari Cohen ’01 (Psychology) worked as a technology specialist for several years before returning to academia as  PhD student in the Energy and Resources Group at UC Berkeley.

Congratulations to all the winners!

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