Tobias Dwyer, PhD

Scientist, Engineer, Microbe Enthusiast

Postdoctoral Researcher At Institute of Science and Technology Austria (ISTA) - Saric Group

About Me

I am a postdoctoral researcher at the Institute of Science and Technology Austria (ISTA) in Professor Andela Saric’s group. Here my work forcuses on the biophysics of cells, using soft matter simulation methods to understand how our cells do incredible feats.I completed my PhD at the University of Michigan working in Professor Sharon Glotzer’s Group in 2025. Here I worked on a variety of projects including, how binary 2D assemblies of particles make porous host-guest networks, how some cell shapes settle into ordered structures, how charged nanoparticles self-assemble, how DNA nano-objects self-assemble, and how particles move through porous media (visit my research interests page to learn more). In addition to working on these research projects I also work as a developer and maintainer of codes in the group, but the bulkwas dedicated to the group’s geometry package, coxeter. My graduate school experiences shaped me as a researcher and gave me confidence in answering new, complex, and exciting questions.

I went to undergrad at the University of Arkansas where I received my Bachelor’s of Science in Chemical Engineering. During that time I worked in the lab of Professor Lauren Greenlee.I also had two REUs through the National Science Foundation, one at the University of Texas, Austin, under Professor John Ekerdt, and another at Tulane University under Professor Hank Ashbaugh.I owe a lot to these undergraduate experiences, Dr. Greenlee for always believing in me and supporting my interests, Dr. Ekerdt for making me believe I could go to a top tier research university and Hank for making me believe I could be a theorist someday. Go check out their websites they do incredible and interesting work.

Research

I am a soft matter researcher who recently finished up a PhD in chemical engineering. I now am working as a postdoctoral researcher in biophysics, working to understand how cells work incredible feats, keeping us healthy, and navigating complex environments. I have a deep interest in how the methods and ideas of soft matter physics can be applied to biophysics, robotics, and ecology. During my PhD, I focused on how nanoparticles and colloids interact and form complex, ordered assemblies and make collective decisions based on simple rules of interaction. I am now focused creating theories and simulations to understand how a broad class of ameoboid-like cells navigate the complex environments.
In the long term, my research aims to use simulations of how cells navigate their envirnoments to design novel immune therapies.Postdoctoral Research Projects and InterestsImmune Cell NavigationStay tuned for more detailed thoughts hereHow do cells stay coherent?Stay tuned for more detailed thoughts here

PhD Projects and Interests:DNA Nano ObjectsDNA Nano objects have recently been synthesized to take a variety of shapes including wireframe octahedra, tetrahedra, cubes and icosahedra. These DNA objects can self assemble into crystals by themselves and co-assemble with DNA coated nanoparticles allowing for a vast array of crystal structures not previously accessible to nanoparticles. In collaboration with the Gang Group at Columbia, my work pertains to the crystallization of these complex building blocks. I design models that capture features of complex crystallization processes we are interested in studying within a reasonable timescale. With my collaborators, we update these models to ask questions about the self-assembly process and the mechanisms that allow for optimal self assembly.

Out of Equilibrium Nanoparticle AssembliesIn colloidal systems, equilibrium assemblies are often studied as the norm to explain self assembly and guide design of new building blocks. However, the preparation of the building blocks and the process of assembly necessarily occurs far from equilibrium. This can lead to a mismatch between predicted structures from theory or simulation and experimental crystal structures because of non-equilibrium kinetics can drive different crystal structures to form. Work from the Ye lab at Indiana University and the Chen lab at UIUC has for the first time imaged colloidal crystallization in real time and found some methods to control the assembly pathways of complex crystal structures. My work, in collaboration with the Ye lab and Glotzer lab postdoc Tim Moore, involves controlling and theoretically describing the self assembly and crystallization pathway of anisotropic particles in complex non-equilibrium systems. By understanding the interactions between particles we can simulate these systems to better understand assembly pathways and kinetics, and predict which crystal structures will form. We thereby push the limits of simulating complex nanoparticle systems while learning new fundamentals of engineering assembly pathways for nanoparticle superlattices.Tunable Gold Nanoparticle AssembliesI work with gold nanoparticles in a variety of contexts. In my collaborations with the Ye Group and Indiana university I study charged nanocubes constrained to 2D, which you can read more about in the out of equilibrium assembly section. I also work with even more complex systems, including charged tetrahedra in surfactant solutions and model the complex physics underpinning their self assembly into complicated crystal structures.

Biophysics of CellsA variety of biological systems can be studied from the perspective of colloidal physics. The shape and mechanical properties of cells often dictate how they interact in the body and with each other. In particular, I am interested in how red blood cells self organize depending on their properties. Different blood borne illnesses change the shape, mechanical, and chemical properties of red blood cells. Therefore, understanding how they red blood cells aggregate, self organize, and interact with the body will be essential to detecting, and predicting the effects of blood borne illnesses depending on the properties of the blood.The properties of cells are often essential in other aspects. A fascinating example is the growth of colonies of E. coli bacteria, where the mobility of bacteria dramatically influences how the colonies grow. Mobility of the bacteria will smooth out local concentration instabilities of bacteria.Colloidal Tunable Host Guest AssembliesNanoparticle host-guest assemblies are a new class of colloidal structures (currently only realized for hard particles) where a ‘host’ particle forms a orientationally restricted ‘cage’ around a more orientationally and vibrationally free ‘guest’ particle at the center of the cage. In these systems, entropy is compartmentalized, meaning that the host has a lower entropy and the guest has a higher entropy, owing to a higher free volume in the host structure. Entropy compartmentalization has already been discovered for both 2D systems and 3D systems.My work on Host-Guest structures involves tuning the assembly of these structure via simple geometric rules which you can read about in this paper! I have shown in a simple system of tri-tipped concave star particles and convex guest particles, you can tune the guest particle shape to change the underlying crystal structure. I have discovered multiple new 2D host-guest crystals including guest rotators, guest discrete rotator, homo-porous guest crystals (which you can choose based on the guest), and hetero-porous guest crystals. I therefore show that Host-Guest crystals are easily tunable based on guest shape and could be a useful assembly method for assembling high-quality binary crystals.

Publications

Google Scholar: Where you can see all the spicy analytics about my pubs! :DBelow are my publications that have been peer reviewed and accepted. If you would like a more recent and complete list of my projects, please visit my research interests page. Those projects will have their ‘prime time’ moments on this page soon enough.Publication List:
(7) Fang Lu, Yugang Zhang, Tobias Dwyer, Aaron Michelson, Timothy C. Moore, Hanfei Yan, Kim Kisslinger, Honghu Zhang, Xiaobo Chen , Sharon C. Glotzer & Oleg Gang Octo-diamond crystal of nanoscale tetrahedra with interchanging chiral motifs Nature Materials, 21 February 2025.(6) Logan D. Piegols, Tobias Dwyer, Sharon C. Glotzer, and Omolola Eniola-Adefeso Shape-Dependent Structural Order of Red Blood Cells Langmuir, Januray 2025.(5) Zhong, Yaxu, Timothy C. Moore, Tobias Dwyer, Alex Butrum-Griffith, Vincent R. Allen, Jun Chen, Yi Wang, Fanrui Cheng, Sharon C. Glotzer, and Xingchen Ye. Engineering and Direct Imaging of Nanocube Self-Assembly Pathways. Nature Chemical Engineering, August 6, 2024, 1–10.(4) Dwyer, T., C. Moore, T., A. Anderson, J. & C. Glotzer, S. Tunable assembly of host–guest colloidal crystals. Soft Matter 19, 7011–7019 (2023).(3) Ramasubramani, V., Dice, B., Dwyer, T. & Glotzer, S. coxeter: A Python package for working with shapes. JOSS 6, 3098 (2021).(2) Du Tang, Tobias Dwyer, Hussain Bukannan, Odella Blackmon, Courtney Delpo, J. Wesley Barnett, Bruce C. Gibb, and Henry S. Ashbaugh Pressure Induced Wetting and Dewetting of the Nonpolar Pocket of Deep-Cavity Cavitands in Water | The Journal of Physical Chemistry B. (2020).(1) Zhang, Z., Dwyer, T., Sirard, S. M. & Ekerdt, J. G. Area-selective atomic layer deposition of cobalt oxide to generate patterned cobalt films. Journal of Vacuum Science & Technology A ALD2019, 020905 (2019).

Outreach

Mentorship:I have worked for several outreach/mentorship programs at the University of Michigan. Among them are SLATE, an organization mentoring middle and high school students in the Ann Arbor area, Posse, an organization that works with current undergraduate students to thrive in college, and as a peer mentor for incoming chemical engineering graduate students.I also worked as lead mentor for all chemical engineering graduate mentors where I both led mentorship efforts for first year graduate students and led the intro to graduate school course.I have mentored several undergraduate researchers, 2 have graduated winter semester 2022, both taking jobs in industry. My third mentee, Katherine Ellis, is now a PhD student at Northwestern University. While working with me she developed simulations of active matter in fluctuating environments in collaboration with the Schwartz Lab at University of Colorado, Boulder.Curriculum:In the wake of the BLM protests in 2020, several graduate students, including myself, have begun work on adding needed but missing topics to the chemical engineering curriculum. Working with faculty, we work to add topics such as environmental racism, and social justice to the classic chemical engineering curriculum and ask students to consider important ethical questions about their actions as engineers. We have added these issues to a diverse set of courses including fluid mechanics, heat and mass transport, material balances, senior design courses, and our introduction to graduate school course. My contributions to these efforts have included making new lecture materials from scratch, designing homework problems, and creating a vision for how these topics can be incorporated into the chemical engineering curriculum.