Decoding a Material’s ‘Memory’

by Erica K. Brockmeier

A suspension of particles of different sizes during shearing experiments conducted in the lab of Paulo Arratia, with arrows indicating particle “flow” and trajectories. In a new study published in Nature Physics, researchers detail the relationship between a disordered material’s individual particle arrangement and how it reacts to external stressors. The study also found that these materials have “memory” that can be used to predict how and when they will flow. (Image: Arratia lab)

New research published in Nature Physics details the relationship between a disordered material’s individual particle arrangement and how it reacts to external stressors. The study also found that these materials have “memory” that can be used to predict how and when they will flow. The study was led by Larry Galloway, a Ph.D. student in the lab of Paulo Arratia, and Xiaoguang Ma, a former postdoc in the lab of Arjun Yodh, in collaboration with researchers in the labs of Douglas Jerolmack and Celia Reina.

A disordered material is randomly arranged at the particle-scale, e.g. atoms or grains, instead of being systematically distributed—think of a pile of sand instead of a neatly stacked brick wall. Researchers in the Arratia lab are studying this class of materials as part of Penn’s Materials Research Science & Engineering Center, where one of the program’s focuses is on understanding the organization and proliferation of particle-scale rearrangements in disordered, amorphous materials.

The key question in this study was whether one could observe the structure of a disordered material and have some indication as to how stable it is or when it might begin to break apart. This is known as the yield point, or when the material “flows” and begins to move in response to external forces. “For example, if you look at the grains of a sand castle and how they are arranged, can I tell you whether the wind can blow it over or if it has to be hit hard to fall over?” says Arratia. “We want to know, just by looking at the way the particles are arranged, if we can say anything about the way they’re going to flow or if they are going to flow at all.”

While it has been known that individual particle distribution influences yield point, or flow, in disordered materials, it has been challenging to study this phenomenon since the field lacks ways to “quantify” disorder in such materials. To address this challenge, the researchers collaborated with colleagues from across campus to combine expertise across the fields of experimentation, theory, and simulations.

Read the full story in Penn Today.

The authors are Larry Galloway, Erin Teich, Christoph Kammer, Ian Graham, Celia Reina, Douglas Jerolmack, Arjun Yodh, and Paulo Arratia from Penn; Xiaoguang Ma, previously a postdoc at Penn and now at the Southern University of Science and Technology in Shenzhen, China; and Nathan Keim, previously a postdoc at Penn and now at Pennsylvania State University.

Arjun Yodh is the James M. Skinner Professor of Science in the Department of Physics and Astronomy in Penn’s School of Arts & Sciences and a member of the Penn Bioengineering Graduate Group.

Paulo Arratia is a professor in the departments of Mechanical Engineering and Applied Mechanics and Chemical and Biomolecular Engineering in the School of Engineering and Applied Science at the University of Pennsylvania.

Douglas Jerolmack is a professor in the Department of Earth and Environmental Science in Penn’s School of Arts & Sciences and in the Department of Mechanical Engineering and Applied Mechanics at Penn Engineering.

Celia Reina is the William K. Gemmill Term Assistant Professor in the Department of Mechanical Engineering and Applied Mechanics at Penn Engineering.

Penn Bioengineering Student Laila Barakat Norford Named Goldwater Scholar

Laila Barakat Norford (Class of 2023)

Five University of Pennsylvania undergraduates have received 2022 Goldwater Scholarships, including Laila Barakat Norford, a third year Bioengineering major from Wayne, Pennsylvania. Goldwater Scholarships are awarded to sophomores or juniors planning research careers in mathematics, the natural sciences, or engineering.

She is among the 417 students named 2022 Goldwater Scholars from the 1,242 students nominated by 433 academic institutions in the United States, according to the Barry Goldwater Scholarship & Excellence in Education Foundation. Each scholarship provides as much as $7,500 each year for as many as two years of undergraduate study.

Penn has produced 23 Goldwater Scholars in the past seven years and a total of 55 since Congress established the scholarship in 1986.

Laila Barakat Norford is majoring in bioengineering with minors in computer science and bioethics in Penn Engineering. As a Rachleff Scholar, Norford has been engaged in systems biology research since her first year. Her current research uses machine learning to predict cell types in intestinal organoids from live-cell images, enabling the mechanisms of development and disease to be characterized in detail. At Penn, she is an Orientation Peer Advisor, a volunteer with Advancing Women in Engineering and the Penn Society of Women Engineers, and a teaching assistant for introductory computer science. She is secretary of the Penn Band, plays the clarinet, and is a member of the Band’s Fanfare Honor Society for service and leadership. Norford registers voters with Penn Leads the Vote and canvasses for state government candidates. She is also involved in Penn’s LGBTQ+ community as a member of PennAces. Norford plans to pursue a Ph.D. in computational biology, aspiring to build computational tools to address understudied diseases and health disparities.

The students applied for the Goldwater Scholarship with assistance from Penn’s Center for Undergraduate Research and Fellowships.

Read about all five 2022 Penn Goldwater Scholars in Penn Today.

Ossum Technologies Wins 2022 Y-Prize

Team Ossum Technologies

Ossum Technologies, a team of Penn undergraduates including several Bioengineering majors, has won the 2022 Y-Prize Competition. The annual Y-Prize Competition, which includes a $10,000 award, is sponsored by Penn Engineering, the William and Phyllis Mack Institute for Innovation Management at the Wharton School, the Venture Lab, and the Penn Center for Innovation, “challenges students to discover the hidden potential in Penn research” by taking technology from the lab to the marketplace.

Traditional hook versus OsPass

Team Ossum is comprosed of Ananya Dewan (Vagelos LSM), Hoang Le (Vagelos LSM), Shiva Teerdhala (Vagelos LSM), Karan Shah (SEAS), and Savan Patel (M&T). Karan and Savan are both bioengineering majors. Their winning pitch to a panel of expert judges proposed “a commercial application to remove obstacles to safe cerclage use in orthopedic fracture fixation with Penn’s steerable needle technology.” Initial work for Ossum’s device, OsPass, was done in the George H. Stephenson Foundation Educational Laboratory & Bio-MakerSpace, the primary teaching lab and interdisciplinary makerspace of the Department of Bioengineering which is open to any Penn students campus-wide.

Team Steed, who proposed “an application to make breast biopsies less painful and damaging,” placed among the competition finalists and included bioengineering majors Farhaanah Mohideen, Ananyaa Kumar, and Kristina Khaw.

Read the full announcement on the Mack Institute website.

Herman P. Schwan Distinguished Lecture: “Nucleoside-modified mRNA-LNP therapeutics” (Drew Weissman, Perelman School of Medicine)

We hope you will join us for the Spring 2022 Herman P. Schwan Distinguished Lecture by Dr. Drew Weissman, hosted by the Department of Bioengineering.

Date: Tuesday, March 29, 2022
Time: 3:30-5:00 PM
Location: Bodek Lounge, Houston Hall
Reception to follow
Zoom Link
Password: schwan22

Drew Weissman, M.D., Ph.D.

Speaker: Drew Weissman, M.D., Ph.D.
Roberts Family Professor in Vaccine Research, Department of Medicine
Perelman School of Medicine
University of Pennsylvania


Vaccines prevent 4-5 million deaths a year making them the principal tool of medical intervention worldwide. Nucleoside-modified mRNA was developed over 15 years ago and has become the darling of the COVID-19 pandemic with the first 2 FDA approved vaccines based on it. These vaccines show greater than 90% efficacy and outstanding safety in clinical use. The mechanism for the outstanding immune response induction are the prolonged production of antigen leading to continuous loading of germinal centers and the adjuvant effect of the LNPs, which selectively stimulate T follicular helper cells that drive germinal center responses. Vaccine against many pathogens, including HIV, HCV, HSV2, CMV, universal influenza, coronavirus variants, pancoronavirus, nipah, norovirus, malaria, TB, and many others are currently in development. Nucleoside-modified mRNA is also being developed for therapeutic protein delivery. Clinical trials with mRNA encoded monoclonal antibodies are underway and many other therapeutic or genetic deficient proteins are being developed. Finally, nucleoside-modified mRNA-LNPs are being developed and used for gene therapy. Cas9 knockout to treat transthyretin amyloidosis has shown success in phase 1 trials. We have developed the ability to target specific cells and organs, including lung, brain, heart, CD4+ cells, all T cells, and bone marrow stem cells, with LNPs allowing specific delivery of gene editing and insertion systems to treat diseases such as sickle cell anemia, Nucleoside-modified mRNA will have an enormous potential in the development of new medical therapies.


Drew Weissman, M.D., Ph.D. is a professor of Medicine at the Perelman School of Medicine, University of Pennsylvania. He received his graduate degrees from Boston University School of Medicine. Dr. Weissman, in collaboration with Dr. Katalin Karikó, discovered the ability of modified nucleosides in RNA to suppress activation of innate immune sensors and increase the translation of mRNA containing certain modified nucleosides. The nucleoside-modified mRNA-lipid nanoparticle vaccine platform Dr. Weissman’s lab created is used in the first 2 approved COVID-19 vaccines by Pfizer/BioNTech and Moderna. They continue to develop other vaccines that induce potent antibody and T cell responses with mRNA–based vaccines. Dr. Weissman’s lab also develops methods to replace genetically deficient proteins, edit the genome, and specifically target cells and organs with mRNA-LNPs, including lung, heart, brain, CD4+ cells, all T cells, and bone marrow stem cells.

About the Schwan Lecture:

The Herman P. Schwan Distinguished Lecture is in honor of one of the founding members of the Department of Bioengineering, who emigrated from Germany after World War II and helped create the field of bioengineering in the US. It recognizes people with a similar transformative impact on the field of bioengineering.

Bionegineering Spin-off Vivodyne on Fast Company’s ‘Most Innovative’ List

Andrei Georgescu (left) and Dan Huh developed several organ-on-a-chip platforms in Huh’s lab. Their spin-off company, Vivodyne, aims to use the technology as a scalable alternative to animal testing in the pharmaceutical industry.

With Vivodyne, Associate Professor in the Department of Bioengineering Dan Huh is translating the organs-on-chips technology into a promising industry venture. Using microfluidic structures that mimic aspects of human physiology, organs-on-chips allow scientists to test therapies on lab-grown human cells. Vivodyne specifically focuses on designing organs-on-chips to create a scalable alternative for pharmaceutical drug testing on animals.

Last year, the company raised $4 million dollars in seed money. This year, it’s topping influential lists of small companies making big impacts.

Fast Company now lists it as one of “the 10 most innovative companies with fewer than 10 employees,”  saying “Vivodyne is helping major pharmaceutical companies like GlaxoSmithKline quickly adopt viable alternatives for testing drugs on monkeys.”

Vivodyne, launched in 2021, has created a platform that allows fully automated, complex studies at a far larger scale and lower cost than would be possible with manual experimentation, so pharmaceutical companies can actually test lab-made organs instead of animals in their drug-development processes. When done by hand, only 20 to 40 living tissue samples can be managed in parallel; Vivodyne’s instrument can cultivate, dose, and image more than 2,000 living tissues at once. The company, which raised $4 million in seed funding last year, says its instruments currently play pivotal roles in clinical drug testing for respiratory diseases, cancer treatment, vaccine development, diabetes therapies, and maternal medicine. GlaxoSmithKline, one of Vivodyne’s clients, estimates that for some projects the lab-grown tissues may displace as much as 80% of its animal testing. The company’s ultimate goal? “To supplant the vast majority of animal testing within the next decade,” says CEO Andrei Georgescu.

Continue reading “The 10 most innovative companies with fewer than 10 employees” at Fast Company.

Originally posted in Penn Engineering today.

Konrad Kording Appointed Co-Director the CIFAR Learning in Machines & Brains Program

Konrad Kording, PhD (Photo by Eric Sucar)

Konrad Kording, Nathan Francis Mossell University Professor in Bioengineering, Neuroscience, and Computer and Information Sciences, was appointed the Co-Director of the CIFAR Program in Learning in Machines & Brains. The appointment will start April 1, 2022.

CIFAR is a global research organization that convenes extraordinary minds to address the most important questions facing science and humanity. CIFAR was founded in 1982 and now includes over 400 interdisciplinary fellows and scholars, representing over 130 institutions and 22 countries. CIFAR supports research at all levels of development in areas ranging from Artificial Intelligence and child and brain development, to astrophysics and quantum computing. The program in Learning in Machines & Brains brings together international scientists to examine “how artificial neural networks could be inspired by the human brain, and developing the powerful technique of deep learning.” Scientists, industry experts, and policymakers in the program are working to understand the computational and mathematical principles behind learning, whether in brains or in machines, in order to understand human intelligence and improve the engineering of machine learning. As Co-Director, Kording will oversee the collective intellectual development of the LMB program which includes over 30 Fellows, Advisors, and Global Scholars. The program is also co-directed by Yoshua Benigo, the Canada CIFAR AI Chair and Professor in Computer Science and Operations Research at Université de Montréal.

Kording, a Penn Integrates Knowledge (PIK) Professor, was previously named an associate fellow of CIFAR in 2017. Kording’s groundbreaking interdisciplinary research uses data science to advance a broad range of topics that include understanding brain function, improving personalized medicine, collaborating with clinicians to diagnose diseases based on mobile phone data and even understanding the careers of professors. Across many areas of biomedical research, his group analyzes large datasets to test new models and thus get closer to an understanding of complex problems in bioengineering, neuroscience and beyond.

Visit Kording’s lab website and CIFAR profile page to learn more about his work in neuroscience, data science, and deep learning.

Decade-long Remission After CAR T Cell Therapy

Bill Ludwig, left, was the first patient to receive CAR T cells as part of clinical trials at Abramson Cancer Center. Carl June, right, has played a pioneering roll in the therapeutic use of CAR T cells. (Image: Penn Medicine)

Carl H. June, the Richard W. Vague Professor in Immunotherapy in Pathology and Laboratory Medicine at Penn Medicine, director of the Center for Cellular Immunotherapies and the Parker Institute for Cancer Immunotherapy, and member of the Penn Bioengineering Graduate Group at the University of Pennsylvania, has led a new analytical study published in Nature that explains the longest persistence of CAR T cell therapy recorded to date against chronic lymphocytic leukemia (CLL), and shows that the CAR T cells remained detectable at least a decade after infusion, with sustained remission in both patients. June’s pioneering work in gene therapy led to the FDA approval for the CAR T therapy (sold by Novartis as Kymriah) for treating leukemia and transforming the fight against cancer. His lab develops new forms of T cell based therapies.

Read the story in Penn Today