THE MELODIES OF MATERIALS
Materials science is at the heart of innovation, shaping the tools and technologies of our modern world. Let's dive into the intricacies behind the materials that define the music and sounds of our lives.
04/19/2026 ⋅ By Rishi Pai ⋅ 8 min read
Coacervates, Cold Chains, and Curiosity: A Conversation with Dr. Sarah Perry
Interview (Zoom Meeting) with Dr. Sarah Perry from UMass Amherst
One of the most rewarding parts of pursuing research at a young age is what it unlocks beyond the lab bench. Earlier this month, I had the privilege of sitting down with Dr. Sarah Perry, Professor of Chemical and Biomolecular Engineering at the University of Massachusetts, Amherst, for a nearly hour-long discussion about coacervate science, polymer chemistry, and the kind of winding scientific career path that I find genuinely inspiring. I walked away with more clarity, more questions, and more excitement about the field than I had going in.
A Path That Didn't Go in a Straight Line
One of the first things I noticed when reading Dr. Perry's bio was how nonlinear her trajectory has been, and I wanted to hear her tell that story herself. She holds bachelor's degrees in both chemistry and chemical engineering from the University of Arizona, a master's from the same institution, and a PhD in Chemical Engineering from the University of Illinois at Urbana-Champaign. But what struck me was how far each chapter of her career strayed from the one before it.
She started in undergraduate research focused on semiconductor processing, working toward a more additive approach to chip manufacturing, one that grows layers up rather than patterning and etching them away. That interest in molecular-level control carried her into her PhD, where she fully expected to continue in that vein. Instead, she ended up working on a project involving membrane proteins, lipid phases, and self-assembling structures, areas that had essentially nothing to do with semiconductors. By the time she finished her PhD and moved through a postdoc at UC Berkeley and then the University of Chicago, she had arrived at coacervates, the very subject she now leads a research group around.
The through line, as she put it, was always self-assembly. That instinct to understand how molecules organize themselves has held through every pivot, even when the systems themselves looked completely different on the surface.
Why Coacervates Are So Compelling
When I asked what she finds most scientifically interesting about coacervate science, Dr. Perry didn't hesitate. It's the breadth. Coacervates, at their core, form when two oppositely charged polymers interact and phase separate into a polymer-rich droplet. But what you can do with that basic phenomenon is remarkably wide-ranging.
On the biological side, coacervates are closely related to what scientists call biomolecular condensates, the membrane-less compartments inside cells that selectively sequester specific proteins or RNA molecules. Understanding how and why they pull down certain molecules, and how disruptions to those condensates contribute to disease, is one of the most active areas of research in cell biology right now. Dr. Perry described work out of the Max Planck Institute that led to the formation of a company called Dew Point Therapeutics, which uses microscopy to map where drugs go inside cancer cells and correlates that with drug resistance. In some cases, a drug might be getting trapped inside a condensate rather than reaching its target. That is not a small detail; it could fundamentally change how therapeutics are designed.
On the materials side, the possibilities are just as exciting. Coacervates can be deposited from water, which gives them an inherent environmental advantage over coatings that require harsh organic solvents. Dr. Perry mentioned industrial reactor vessels that currently require cross-linked, chemically reactive coatings that are hazardous to apply and nearly impossible to recycle. A coacervate-based coating deposited from water and actually strengthened by contact with organic solvents could change that calculus significantly. Her lab has even made solvent-free nail polish from coacervates, entirely water-based. The range is almost disorienting, in the best way.
The Entropy Behind It All
One of the most clarifying moments of our conversation came when Dr. Perry explained the thermodynamic foundation of why coacervates form at all. The intuitive assumption is that two oppositely charged polymers come together because of electrostatic attraction, an enthalpic process. But that is not quite the full story. The real driving force is entropic.
When two oppositely charged polymer chains associate and self-neutralize, they release the small counter-ions that were previously needed to balance their charges. Sodium, chloride, and others that were essentially pinned near the polymer are suddenly free to move through solution. Entropy, understood as the number of available states rather than just disorder, increases when those counter-ions are liberated. And that entropic gain is what actually drives the phase separation.
This has a fascinating consequence for polymer design. If charges are clustered densely along a chain rather than evenly spaced, those counter-ions are forced to sit very close together, and upon release, they gain significantly more entropic freedom. The interactions become stronger and the material more stable, even if the total number of charges stays the same. Sequence and patterning, not just composition, matter enormously.
Keeping Vaccines Alive Without a Refrigerator
A significant portion of our conversation turned to one of the more impactful applications of Dr. Perry's research: using coacervates to stabilize biomolecules, including vaccines, without requiring refrigeration. The pharmaceutical cold chain, keeping vaccines between two and eight degrees Celsius from manufacturing to patient, is an enormous logistical and economic burden, especially in lower-resource settings.
Dr. Perry drew a useful distinction between stabilizing small molecule drugs, which mostly involves preventing chemical bond degradation, and stabilizing biomolecules like proteins or mRNA vaccines, where the challenge is keeping something folded, protected from enzymes, and biologically active. The cell itself is actually a useful model here. The cytoplasm is roughly 30 percent protein by mass and operates at 37 degrees Celsius, yet proteins remain stable. Coacervation inside cells provides compartmentalization, physical crowding that suppresses unfolding, and a molecular environment tuned to be stabilizing. Dr. Perry's lab is trying to recreate that environment artificially, using coacervate formulations where longer polymer chains create denser physical crowding, and where sequence changes can tune the molecular interactions even further. The results so far are promising, and a paper going deeper into the mechanism was in revision at the time of our conversation.
Waterfall Scientific and the Road from Lab to Company
Toward the end of our conversation, I asked Dr. Perry about Waterfall Scientific, the startup she co-founded with a collaborator at UMass. The company addresses a real bottleneck in RNA therapeutics: current manufacturing methods for RNA are done in batch, which is costly and limiting. Waterfall Scientific is developing a continuous processing approach using microfluidics technology that Dr. Perry brought to the collaboration.
What I found interesting about her account was how organically it started. A colleague approached her with an idea, she didn't have the bandwidth for a full collaboration, so instead she had his student join her microfluidics course as a project. That class project became the basis for a patent, which became the foundation for the startup. From a single classroom assignment, they now share co-advised postdocs and a PhD student, and multiple grants. Dr. Perry serves as chair of the Technical Advisory Committee rather than running day-to-day operations, but the scientific foundation is very much hers.
What People Get Wrong About Soft Materials
I asked Dr. Perry what she thinks the biggest misconception people have about coacervates or soft materials in general. Her answer surprised me in its simplicity. She said that most people think of plastics as objects, not as interacting molecules. When someone hears the word polymer, they picture a desk or a plastic cup, something static and fixed. What they don't naturally think about is the molecular-level interactions that determine whether a polymer behaves one way or another. The jump from microscopic interactions to macroscopic behavior is not intuitive, and bridging that gap is genuinely one of the core challenges of materials communication.
It's something I've thought about in the context of this blog. The whole point of what I'm trying to do here is to make that connection legible, to show how the molecular scale and the human scale are not as far apart as they seem.
Closing Thoughts
Speaking with Dr. Perry was one of the richer scientific conversations I've had, not just because of the depth of her knowledge but because of how naturally she engages with ideas across disciplines. She has spent her career moving between worlds, semiconductors, microfluidics, structural biology, soft matter, and rather than compartmentalizing those experiences, she has let them inform each other. That kind of intellectual range is something I deeply admire and hope to cultivate in my own path.
I am grateful to Dr. Perry for her generosity with both her time and her thinking. There is still so much to explore in the world of coacervates, and conversations like this one remind me how much of that exploration remains ahead. So until dhin... stay upbeat, and stay tuned.