For the People, By the People: Early career researchers organize virtual polymer physics symposium

2020 Virtual Polymer Physics Symposium

Symposium Website: 2020 Virtual Polymer Physics Symposium


In these unprecedented and fluid times, conferences and symposia have gone virtual as STEM collectively settles into a new normal. Many large meetings, like the formerly “in-person only” American Physical Society (APS) and American Chemical Society (ACS) national meetings, have been canceled or transitioned to virtual-only participation this year. The 2021 Spring APS meeting will go virtual as well. I love big in-person meetings and have shied away from virtual alternatives thinking they would not provide the same feeling of community with my fellow scientists. However, the isolation of quarantine and the desire to get comfortable with the “new normal” motivated me to step out of my comfort zone and into the world of virtual science meetings this summer. So, when the opportunity to attend the 2020 Virtual Polymer Physics Symposium (VPPS) arose in July, I jumped at the chance to participate. 

The 2020 VPPS was a two-day virtual event organized to fill the void left by the cancellation of the 2020 Polymer Physics Gordon Research Seminar . The event was organized by two early career researchers (ECRs), Konane Bay from Princeton, and Whitney Loo from UC Berkeley, the current co-chairs of the Polymer Physics Gordon Research Seminar (GRS). 

The Polymer Physics GRS is held biennially; the last seminar was in 2018 and, due to the pandemic, the next one won’t occur until 2022. “Two years feels like a lifetime to ECRs and we know many of our colleagues will be at different institutions and career stages in 2022, so we wanted to create a space for them to share and discuss their recent research,” explains Konane. The 2020 VPPS connected more than 100 scientists, including 20 ECRs presenting their work across four oral presentation sessions during the two-day event. In the spirit of the Polymer Physics GRS, this new virtual event also incorporated professional development and discussion sessions, including a Mentorship Panel and the “Dispersity and Diversity Hour” discussion focused on how to increase diversity, equity, and inclusion (DEI) in the field of polymer physics and the broader scientific community.

The Mentorship Panel included researchers at different career stages working in academia, industry, or government research. The discussion was focused on steps students and postdocs can take to prepare for future careers in polymer physics as we adapt to a global pandemic. The panelists emphasized the quarantine-proof nature of computational work since it can often be done anywhere including at home and encouraged experimentalists to broaden their computational skill set. Both Nate Lynd, assistant professor at UT Austin, and Michelle Sing, an engineer at Braksem USA, suggested that experimentalists should become familiar with Python as a first step. Debra Audus, a scientist at NIST, highlighted lab work automation and strategic experiment planning to maximize “in-lab” time during the transition to shift-style lab work that many American universities have adopted as a way to overcome the challenges related to performing socially distanced science. 

Participating in the “Dispersity and Diversity Hour” required some homework. The organizers asked all attendees to prepare for the discussion by reading about the experience of Black researchers in STEM (links below). Ben Yavitt, a Stony Brook University postdoc, opened the event by emphasizing that the goal of the discussion was to brainstorm potential solutions to address the issues spotlighted by national movements such as #BLM, #ShutdownSTEM, and #BlackintheIvory. More than 70 attendees participated in small group discussions across 15 breakout rooms led by volunteer discussion leaders. This event was an important first step in raising awareness of the necessary academic culture shift required to empower more scientists of color to pursue careers in soft matter and polymer physics.

Overall, the meeting events were very well moderated and designed for maximum virtual engagement during both the science presentations and the discussion sessions. For me, attending this event clarified the current trajectory of the polymer physics field as it transitions from fundamental studies to applied research focused on exploiting polymer physics for advanced technology. This transition in research focus was evident in some of the science presented during the symposium. While I was apprehensive about the shift to virtual meetings and conferences, attending the 2020 VPPS has won me over. I highly recommend taking advantage of the proliferation of virtual science conferences and symposia to stay engaged, learn about new science and perspectives, and do some networking along the way!

Diversity and Diversity Hour Resources
Science Is For Everyone — Until It’s Not
Your Black Colleagues May Look Like They’re Okay — Chances Are They’re Not
AIP Team-Up Report Executive Summary

Disclosure: I am acquainted with Konane Bay, one of the event co-organizers. She was a graduate student in my department, UMass Amherst Department of Polymer Science and Engineering. However, I was not involved in any way with the organization of the VPPS. 

PARNET 2019: Granular and Particulate Networks

A granular material, such as sand, coffee beans, or balls in ball pit, is a collection of particles that interact with each other and dissipate energy. These materials can act like solids, flow like liquids, or suddenly transition between the two phases – for example, in a landslide, the soil stops holding its shape and flows. The Granular and Particulate Networks Workshop, PARNET19, brought together the physicists, engineers, and mathematicians who study these materials in a series of lectures and discussions.

Figure 1. Examples of granular materials: a. sand, b. coffee beans and c. a ball pit. 

PARNET19 took place at the Max Planck Institute in Dresden, Germany on July 8-10, 2019. I attended to represent Softbites at the science communication panel and to present my research on fly larvae as an active granular material.

The focus of the workshop was exploring the networks formed by the forces in granular materials. When granular materials are stretched or squeezed, they form networks of high forces known as force chains. These networks can be visualized with photoelastic disks, as described by this previous Softbites post.  In a series of 30 minute to 1 hour long scientific talks at PARNET19, the experimentalists who study granular materials and mathematicians who study topological networks discussed how network math can be applied to the force chains found in granular materials. Unusually, talks were followed by 30-minute discussion sessions in which the previous speakers answered questions and posed some of their own.

Modeling granular materials is difficult because they are made up of many individual particles. Simulating the interactions of all of the particles takes a very long time, even with a powerful computer: imagine trying to predict the motion of each sand grain on a beach! The other traditional way to model a granular material is with a continuum model — considering the material as a smooth (continuous) mass, instead of keeping track of individual particles. This works for materials like fluids or solids because the individual molecules that make them up are so small that their individual interactions don’t need to be understood. However, the relevant particles in a granular material are much bigger, relative to the size of the material as a whole, than molecules, which makes the interactions between the particles important. In a granular material, the critical interactions between the particles can result in sudden transitions such as landslides.

The approach taken by the PARNET workshop was to model the part of granular materials that will cause the entire material to change if it moves — the force chains through the grains. The goal of the workshop was to apply existing mathematical theories used to model networks, such as the connection of roads on a map, to understanding the connections of force chains in granular materials. For example, understanding when a force chain in the rocks making up a cliff is likely to fail can inform workers near the cliff about impending danger and allow them to evacuate before a landslide occurs.

Figure 2. Connecting granular materials experiments, such as the force chains pictured in (a), with pure network math, such as the Konigsberg bridge problem pictured in (b), was the main theme of the workshop. This problem gets challenging if we consider real, 3D materials

The scientific communication panel I was part of discussed a variety of topics, such as publishing journal articles in high or low impact factor journals, making scientific journals open access, and writing for a broad audience. A result of the discussion, we made the Softbites style guide publicly available – everyone wanted to read how we write and edit our posts! 

Group photo

For me, the main takeaway of the workshop was that the network view of granular materials is a promising one to predict catastrophic events. Understanding what causes a force chain to break can explain why some arrangements of granular materials are stable for a long time while others come crashing down with no obvious warning. However, connecting the complex and chaotic real-life granular materials in 3D to the purely theoretical math behind topological networks will prove challenging. Mathematical models of networks can be very abstract, and these theories need to be connected to physics in the real world. As with any theory, it is important to verify predictions with real-life experiments, but the force chains inside granular materials are difficult to measure.

Overall, this was one of the best conferences I’ve attended as a graduate student. The format of longer discussion sessions was very effective, as it allowed more time for elaborating on each speaker’s points than the traditional 5 minute long Q&A sessions. The PARNET workshop was a useful introduction to a new (to me) way of thinking about granular materials, one which I am implementing in my own research. If complex systems, such as granular materials, can be modeled by a simple set of topological equations, they will be much easier to understand and predict in future studies.

2019 MRSEC Brandeis Microfluidics summer course

If you just landed on Softbites for the first time, you probably have not had the chance to read our previous posts about microfluidics (like this one, or that one, and more). If this field of science is foreign to you, all you need to know is that it studies how fluids flow at really small scales (typically tens to hundreds of micrometers). For instance, you can quickly generate tiny droplets of a solution, turning each droplet into an individual “reactor”. Or you can create  microenvironments with precisely controlled chemical concentrations to grow cells in different conditions.

In addition to being a thriving field of research, I think microfluidics is simply beautiful! I have spent hours looking at the Softbites website’s banner, a movie of droplets that was shot by the Lutetium project. You can imagine my excitement when I registered to the annual MRSEC microfluidics summer course 2019 at Brandeis University. This summer course was run by four talented grad students from the Fraden lab and the Rogers lab: Ali Aghvami, Alex Hensley, Marilena Moustaka and Zahra Zarei. These labs are part of the MRSEC program at Brandeis, an important place in the New England soft matter community. Therefore, I think it was the perfect place to get started with microfluidics!

Figure 1. Me, trying to pour some resin on a silicon wafer (left). A drop maker setup (middle). A gradient maker chip, with a defect leading to a non-stable gradient (right).

Over five days, we learned the basics of one of the standard methods for making microfluidic channels, called soft lithography. The rationale is to make a mold using a UV-light sensitive resin. A 2D pattern can then be polymerized in the resin by shining UV-light through a mask. Whatever the UV light hits gets hard, while the rest of the resin stays soft. The soft resin is washed away leaving only the hard, UV-treated resin behind in the shape of the mask. The mold will finally be used to imprint the design in a soft transparent material called PDMS (a very nice video from the Lutetium project explains all this process). We experimented with this fabrication during three main sessions: 

  1. We drew our 2D design using a drawing software 
  2. We fabricated our mold in a clean room so no dust ruined our tiny features
  3. We cast the PDMS on the mold and sealed the device with a glass slide

We were taught each of these steps through a combination of lectures and hands-on sessions. You can see a droplet maker and a gradient making device that we made in Figure 1. 

In addition to learning how to make these routinely used PDMS-based devices, we were also introduced to another technique used in the Fraden lab. This technique, which was recently published (2017), uses a thermoplastic (a plastic that melts at moderate temperatures) as the main device material. This thermoplastic can be cast onto a PDMS mold by means of a thermopress (as shown in Figure 2). Unlike PDMS, thermoplastic is not permeable to water and organic solvent, and is stiffer. If the permeability of PDMS is a limitation for your microfluidics application, thermoplastic might be the way to go!

Figure 2. Ali Aghvami placing thermoplastic chips onto the PDMS mold (left). Close-up on the thermoplastic in the thermopress before being cast (middle). The final device (right), from Aghvami et al. 2017.

This week-long course introduced us to both classical microfluidics techniques that are routinely used in labs and some more advanced ones. More importantly, our instructors dedicated important time to discuss our personal projects with us. We even had a consulting session with Seth Fraden! I strongly encourage anyone to attend the next editions of this course. Each year, the dates and the call for applications are released in spring, so don’t miss out!

These were my first drops! I literally spent 45 minutes watching them!

Biological Materials at SICB 2019

It’s unusual to run a symposium as a PhD student, but anyone can do it! I was lucky to find a great mentor to guide me through the process. Together we organized 11 speakers, 2 workshops, and 11 poster presentations for a full day discussion on what soft matter, materials, and evolutionary biology have in common. From fire ants to spider silk, tooth enamel to lizard scales, and chemistry to computer science, there are lots of opportunities for soft-matter researchers to study biological questions.

The annual meeting of the Society for Integrative and Comparative Biology (SICB) is one of the core conferences for organismal biology. Originally called the “American Society of Zoologists,” the society changed its name to SICB in 1996 to emphasize the “integration” of different biological specializations. This commitment to interdisciplinary research made SICB the perfect home for my interest in biologically produced materials.

I’m interested in how biomaterials are created and diversify, a topic that draws on soft matter physics, mechanics, and evolutionary biology. There are a lot of exciting questions in this area, but because they are so interdisciplinary, there are not that many people who work on them. Interdisciplinary research often falls outside traditional departments and grant funding options, making these projects hard to design and run. They also require careful communication skills (if you talk to an engineer and an evolutionary biologist about the “evolution of a biomaterial” you might get two very different answers– the engineer might think of “material evolution” as a change during the material’s use (how does it respond to heat or light?), while the biologist might think about changes as the material developed with different organisms over millions of years). Nevertheless, I think interdisciplinary research questions are some of the most exciting and important, and luckily I’m not alone.

Together with my co-organizer, Dr. Mason Dean from the Biomaterials Department of the Max Planck Institute for Colloids and Interfaces, we organized the SICB symposium “Adaptation and Evolution of Biological Materials” (#AEBM #SICB2019) to highlight what is already being done in this field, and to encourage more biologists to start working with materials and soft matter.

Here are some highlights from our speakers:

Entanglement

Beyond “active matter” systems like fish schools or bird flocks, there are also collections of individual organisms that entangle together and behave like squishy, living materials. Prof. David Hu and Prof. Saad Bhamla presented on two different entangled soft matter systems: fire ant swarms and worm blobs. Both can act sometimes like a liquid and sometimes like a solid, depending on how the individuals link together. These systems can be described similarly to collections of molecules, complete with phase separation behavior!

Tunability

Unlike a lot of human-engineered systems, almost all biological materials have multiple functions. Dr. Beth Mortimer studies vibrational communication in spiders, worms, and elephants. Here she presented recent work suggesting the material vibration sensors built into spider legs might be tuned specifically for silk material properties — highlighting how silk has evolved to be both a structural and sensory material.

Assembly

Biological materials are famous for being made of simple, individual components that can assemble into complex structures on their own (i.e. “self assembly” without a human engineer). We had a lot of talks referencing this topic. Dr. Linnea Hesse studies the joints of branching plants to try and learn why they are so sturdy. She found that the vascular bundles that transport water (the equivalent of human capillaries for blood flow) adapt to external forces as the branch grows. This way the bottom of the branch is arranged differently than the top to optimize load bearing.

The organization of vascular bundles in the dragon tree changes during growth, making the joints between branches and the trunk stronger. (Image courtesy of Dr. Linnea Hesse)

On a smaller scale, Prof. Matt Harrington presented on a new model of fiber formation from the velvet worm. Velvet worms shoot slime at their prey, which quickly hardens into fibers with strength comparable to nylon. If that wasn’t cool enough, these fibers can be dissolved in water and then later resolidify! Making them an intriguing model for new biodegradable plastics. Unlike spider silk, which is made of tiny highly ordered fibers, the “silk” of the velvet work seems to be made of relatively disordered charge-stabilized droplets.

Last but not least, Dr. Ainsley Seago has surveyed the colorful nanostructured scales of hundreds of species in two lineages of beetles. Her results suggest that even though these surfaces exhibit many different optical properties, they’re all likely assembled as liquids in a process remarkably similar to the assembly of cell membranes (called lyotropic assembly).

The shiny, bright colors on beetles come from nanostructured scales. (Image courtesy of Dr. Ainsley Seago)

Image Analysis

Dr. Daniel Baum is an expert on computational solutions for automated image analysis. He presented on common approaches for automatically selecting different parts of an image. This is really useful for studying material and biological systems with lots of similar repeating structures, and modeling how these systems respond to external forces. He presented examples of this work applied to the study of sharks and rays, whose soft cartilaginous skeletons are wrapped in a network of tiny, repeating, mineralized plates (called tesserae).

Computational methods, such as the watershed algorithm, can automatically segment different parts of an image and be used to construct 3D models of bones, cartilage, and other material. (Image courtesy of Dr. Daniel Baum)

Hierarchy

The layered organization of materials at different scales (forming a hierarchy of structure) is important for many biological materials’ properties. Dr. Laura Bagge studies invisibility in deep sea ocean life, and she presented how the size of the tiny microfibrils that make up larger muscle fibers can change how opaque an organism is — larger microfibrils have fewer interfaces for light to interact with, allowing the whole body of some shrimp species to be transparent.

These kinds of hierarchies are more commonly associated with strength, as in the example that Dr. Adam van Casteren presented. He studies how enamel, the outer layer of the tooth, resists wear, showing work suggesting that different levels of the material structure (nanostructure vs. microstructure) might respond differently to evolutionary pressure. That means that these hierarchies might have evolved to protect against damage from different types of diets, i.e. abrasion from sand particles in plant-based diets versus fracture from breaking apart bones and shellfish.

Transparent shrimp achieve invisibility by having larger muscle microfibrils. (Image courtesy of Dr. Laura Bagge)

Microfluidics

Fluid transport (both liquids and gases) is crucial for organism survival, so it’s no surprise that many biomaterials have been optimized for this function. Dr. Anna-Christin Joel presented work on how lizard scales and certain spider silks use capillary forces to manipulate fluids. The same capillary control has been harnessed to transport water droplets collected along the body to the mouth for drinking and to make capture silk stick more tightly to prey (by pulling waxes up from the surface of insects).

In a different application of fluid handling, Prof. Cassie Stoddard talked about the large eggs of emus. All eggs have pores that provide airflow to the growing chick, but the pores in emu eggs are forked not straight. This might help solve the challenge of getting enough breathable air into large eggs without weakening the shell enough that it could be crushed by the adult (interestingly this feature is also seen in dinosaur eggs!).

EuroScience Open Forum 2018

“ESOF (EuroScience Open Forum) is the largest interdisciplinary science meeting in Europe. It is dedicated to scientific research and innovation and offers a unique framework for interaction and debate for scientists, innovators, policy makers, business people and the general public.” [1]

This year ESOF was in Toulouse, and I was fortunate enough to be able to attend, so I want to share a few snippets of my time there, and my main takeaways.

There was a huge range of different topics on their programme from science communication and careers, to atomic clocks and plastic pollution. I found choosing between parallel sessions was often difficult. But even though I went to a variety of different sessions, I am going to focus on one major theme kept cropping up. Namely, trust.

How can we, as scientists, build trust in science? How can we trust one another?

For this science and scientists need to be seen as credible. There are no quick fixes, but openness was touted by many at ESOF as a huge step towards building more trust. After all if ‘science is not finished until it’s communicated’ [2] then the public are a huge part of science! Not to mention that for most of us, we are in fact paid by taxpayers.  

Here are some of the different types of openness that people discussed at ESOF2018:

  1. Open Access

Currently, many scientific journal articles are behind paywalls – this means institutions without access to a particular journal are locked out. Even when a journal allows institutes to post papers open access from the institute, this is often after long embargo periods restricting access to the latest science.

  1. Open Data

Even if a paper is open access. The methods and the data shown are often too little for experiments or analysis to be easily reproduced. For private and sensitive data – this is not possible but we can strive for the data to be as open as possible and only unavailable when necessary. If the data is accessible and readable, then anyone can reproduce their analysis, particularly if codes are also made accessible and usable.

  1. Open Communication

To share our research with the public, making something understandable to people outside your field is not enough. We need to open a dialogue between scientists and the public so that the outreach activities are catered to their interests. In particular for influencing policy, the people who our science affects need to be heard.

  1. Open Science

Science is a part of our culture, our history and our future. It would be difficult to find anyone who isn’t affected by science. Allowing people to take part is great for building trust. New initiatives and new technologies are opening the ‘ivory tower’ of academia. Citizen science or crowd-sourced science can bring together the public and scientists, for mass collection of data. And new make-spaces, fab-labs and open source software are making it easier for people to conduct their own experiments, build their own devices and explore science in their free time.

A bit of a culture shift needs to occur within science to highlight these aspects of science. I think, most scientists agree openness is important but often these ‘extra’ activities get put on the back burner as publications, teaching responsibilities and funding applications dominate our time. So, more time needs to be invested in openness, but not at the expense of an individual scientist’s career (or home life). Hiring practices, funders and fellow scientists need to reward and encourage openness within science. So I think it is great that so many people from a range of different places were talking about how to increase openness. 

Overall I thought ESOF2018 was a very friendly conference, with so many passionate people working towards a better scientific process. To hear them talk so passionately, either in how science is funded, publishing, science policy, collaborations with industry, scientific careers, science communication and even the science of science communication was a fantastic experience. 

Let us know if you have any experiences, thoughts, or difficulties on accessing science or how to open up science over twitter (@softbites17 or @emilyeriley) or in the comments down below.

[1] https://www.esof.eu/en/

[2] Quote from Sir Mark Walport, who was Chief Scientific Adviser to the UK government.

 

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