Lucas Meza – UW News /news Thu, 28 May 2026 23:26:36 +0000 en-US hourly 1 https://wordpress.org/?v=6.9.4 May research highlights: Rapid river migration, bean plant defense, tiny tensegrities, more /news/2026/05/28/may-research-highlights-rapid-river-migration-bean-plant-defense-tiny-tensegrities-more/ Thu, 28 May 2026 19:59:39 +0000 /news/?p=91919 How bean plants sense very hungry caterpillars and call for backup
When bean plants sense a caterpillar eating their leaves, they release gases that invite predatory wasps to help defend them. Shown here are two different species of predatory wasps attacking a caterpillar on a bean plant. Photo: Brian Behnken/ÂŇÂ×ÉçÇř

Plants may not appear aggressive, but they can still defend themselves while under attack. When caterpillars chomp the leaves of bean plants, these plants release gases that lure predatory wasps. The wasps prey on the caterpillars, saving the plants from further destruction. In a paper , a UW-led team demonstrated that this defense strategy is run by a protein called INR, or inceptin receptor. The researchers grew bean plants with naturally occurring mutations in the INR gene alongside plants with functional INR in an experimental field in Oaxaca, Mexico. The knock-out plants didn’t emit gases and attracted far fewer wasps. This result helps explain a previous study by this team that first identified the biochemical pathway behind this defense mechanism. These results also showcase how the tiny actions of a single protein can affect the behavior of wasps and caterpillars, and in turn, protect the health of the plant. This could benefit nearby plants as well, the researchers said. Beans are often grown alongside “,” such as corn, with the idea that each plant provides a benefit for the others. Beans help make the soil richer for their companions, and, through the actions of INR, could also protect their neighbors from pests.

For more information, contact senior author , UW associate professor of biology, at astein10@uw.edu.ĚýĚý

The other UW co-authors are , , , and . A full list of co-authors and funding is included .


Decades of satellite data show Himalayan rivers migrating rapidly in response to climate change

The movement of rivers is often described in terms of flowing water, but the path a river takes can also change. Some migration is normal, but in the Himalayas, rivers seem to be scrambling faster than scientists anticipated. In a study , researchers show that rivers in the Tibetan Plateau moved twice as much from 2000 to 2020 as they did from 1980 to 2000. As glaciers melt and frozen ground thaws in response to rising temperatures, rivers are inundated with silty meltwater from surrounding glaciers. The water picks the path of least resistance through softening ground. The “movement” includes small lateral shifts, big swings that cut off entire sections of river and occasionally, . The international team attributes their observations to climate change, which is driving temperatures up faster here than many other places. More than 2 billion people rely on these rivers for fresh water and researchers are concerned about communities downstream, as well as the potential for similar patterns that may play out elsewhere.

For more information, contact co-author , UW professor of Earth and space sciences at bigdirt@uw.edu.ĚýĚý

A full list of co-authors and funding is .


Researchers shrink eye-catching structure down to the nano scaleĚý

Researchers 3D printed tiny tensegrity-inspired structures and then shrank them even further through a heating process, creating lightweight “nanotensegrities” that are up to 250% stiffer than the original structures. Photo: Amitha R. Mulastham/UW Molecular Analysis Facility

made using a network of freestanding bars suspended by a web of thin, tense cables. The organization of the bars and cables allows the network of tension and compression forces to lock everything into place, creating a lightweight yet stiff structure. Tensegrities of different sizes are common in nature — examples include and the that help living cells maintain their shape — as well as in diverse manmade structures like , and . Now, a team of engineers at the UW have found a way to create tensegrities as small as five micrometers across — roughly a tenth of the width of a human hair. in the aptly-named journal Small, researchers used a specialized and a resin compound to print bar-and-cable structures about 30 micrometers across. They then heated the materials to 900 degrees celsius, causing the structures to shrink by over 80%. As they shrank, the thinner cables constricted more than the bars, resulting in nanostructures with specific, locked-in levels of stress that were up to 250% stiffer than the starting structures. The team is now working on ways to build larger materials composed of tiny tensegrities, which could eventually usher in a new class of stiff, light and impact-resistant materials.

For more information, contact lead author , a UW doctoral student of mechanical engineering.

Other UW co-authors are , , Zainab S. Patel, , and . Funding information is included .Ěý


Scientists find a key water source for atmospheric rivers

In December 2025, brought a seemingly endless onslaught of precipitation to Washington that caused and washed away roads and homes. In published in the Journal of Geophysical Research: Atmospheres, UW researchers help explain where all that water came from. They describe a link between the , a weather pattern that brings moisture east across the Pacific, and atmospheric rivers. Hypotheses about this connection have emerged from previous studies, but researchers couldn’t physically draw it until now. By tracking precipitation and wind patterns from 2000 to 2024, the UW researchers show that heavy rainfall and flooding are more likely when MJO is active, which happens several times a year. By identifying the MJO as a key moisture source for powerful atmospheric rivers, the researchers hope to improve forecast accuracy and give people more lead time to prepare for incoming storms.

For more information, contact co-author , UW professor of atmospheric and climate science at shuyic@uw.edu.

Other UW co-authors are and . Funding information is .

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Q&A: A UW materials lab probes the mysteries of toughness at the nano scale /news/2026/01/21/lucas-meza-nanoscale-architecture-nanomaterials-mechanical-engineering/ Wed, 21 Jan 2026 17:13:20 +0000 /news/?p=90387 .wp-video { margin-top: -20px; margin-bottom: 5px; } .wp-video br { display: none; }
A splitscreen image showing a black and white webbed material on the left and a bubbled, foamy black and white material on the right.
Researchers in the Meza Research Group at the ÂŇÂ×ÉçÇř draw inspiration from natural structures to develop new materials. On the left is a scanning electron microscope (SEM) image of naturally occurring spider silk. On the right is an SEM image of an engineered plastic material with a similar structure. The plastic is foamed using tiny carbon dioxide bubbles to make it lighter and tougher. Photo: Haynl et. al/Nature Scientific Reports (left) and Dwivedi et. al/Journal of the Mechanics and Physics of Solids (right).

UPDATE (Feb. 17, 2026): This story has been updated to note Meza’s work with the NSF I-Corps program and CoMotion Innovation Gap Fund.

Biology is full of architecture. Materials like wood, crab shells and bone all contain microscopic structures such as layers, lattices, cells and interwoven fibers. Those structures give natural materials an ideal combination of lightness and toughness, and they’ve inspired engineers to build artificial materials with similar properties. But how those tiny architectures lead to such tough materials is something of a mystery.

In 2019, , assistant professor of mechanical engineering, set up the at the ÂŇÂ×ÉçÇř to tease out the mechanical secrets of structures that are as small as 100 nanometers, which is about the size of a virus. He arrived with an ambitious plan to build a new generation of nanomaterials, but soon discovered that the field was missing a fundamental understanding of toughness at tiny scales.

“We had to go back to basics,” Meza said.Ěý

In the years since, Meza and his team have flipped the script on nanomaterial toughness. They’re applying what they’ve learned to new kinds of bespoke materials, though along the way they’re still surprised by tiny structures behaving in ways they theoretically shouldn’t.

Meza spoke with UW News about his strange and surprising journey into the nano realm.

What questions did you establish your lab to tackle?

Lucas Meza: Very broadly, we’re trying to design better materials, but not by introducing new material chemistries. Instead, we use architecture. This is something humans have done throughout history — think of woven textiles and fabrics, or straw-reinforced mud bricks. These are “architected materials,” where the structure of materials allows us to control useful properties like strength, toughness and flexibility.Ěý

The thing that I was particularly interested in was introducing architecture at the nanoscale. What if, instead of building a wall with bricks, we could use nanoplatelets? Or instead of making fabrics with yarn, we could use nanofibers? How would those properties change?

Engineers have found that nanomaterials are stronger, more flaw resistant and more deformable. The challenge is: How do you actually do something with them? We need to build them into large-scale materials in a way that preserves their unique nanoscale properties.Ěý

What material properties are you most interested in?

LM: We’re using architecture to tinker with a few interrelated properties. The first is a material’s strength, which is how much stress it can take before it permanently deforms. The second is ductility, which is how much a material can stretch before it breaks. Those two features sort of combine to determine a material’s toughness, which is the total amount of energy you have to put into a material to break it.

To give a couple of opposing examples: A ceramic plate is strong, meaning it can take a lot of stress, but it has very low ductility, meaning it barely deforms before breaking. So overall, it’s not a very tough material. Conversely, a rubber band is not strong at all — you can bend and stretch it with very little stress. But, it’s extremely ductile — it can stretch to many times its original dimensions without snapping. So as a result, rubber is very tough.

Credit: ÂŇÂ×ÉçÇř (left) and Envato (right).

Toughness is a particularly interesting property to study because there’s no limit on how tough a material can be. There are very hard limits on how strong and how stiff a material can be, and you can use architecture to optimize them, but you can’t exceed the properties of the base material. On the other hand, you can use architecture to improve the overall toughness of a material.Ěý

Nature has already created a lot of really interesting micro- and nano-structures. Every natural material has to be porous to transport nutrients, and on top of that we see things like lattices in some bone and in sea sponges; shells all have layered architectures; wood and bone are fiber composites; and all of this happens at the micro- and nanoscale.Ěý

There had to be a reason that nature was making these architectural motifs at the micro and nanoscale, and I had a strong hunch that it had to do with toughness.Ěý

What has your lab learned about toughness at the small scale?

LM: Initially, we learned a surprising amount about what we »ĺľ±»ĺ˛Ô’t know. My thought in getting into this work was that people know enough about fracture mechanics — how things break and why — so we can just dive into making really complicated architectures and studying their toughness, like l made by my former doctoral student, . We realized the scientific community has some big gaps in their understanding of fracture toughness. So instead, we had to go simple — basically we pulled and pushed and broke a lot of small things to understand what gives a material ductility and toughness.

We learned that all material behavior centers around something called a “plastic zone size.” Basically, when you pull on a part that has a crack, a little ball of energy builds up right at the tip of that crack. That energy ball grows as you add more stress, and at a certain point it shoots through the sample and causes a break. The size of the ball at its breaking point is the material’s plastic zone size, and it’s different for every material.Ěý

We realized that what makes a material ductile or not . If a material is smaller than its plastic zone size, that ball of energy can’t grow big enough to cause the crack to grow, so instead it spreads outward and the material bends.Ěý

The four material samples in this video are all the same size, but structural differences at the nanoscale produce different levels of ductility. In each example, the cyan color represents the sample’s plastic zone size. In less ductile samples, the cyan-colored area remains small and the material snaps, whereas in more ductile samples, the cyan area spreads out and the material stretches. Credit: Dwivedi et. al/Journal of the Mechanics and Physics of Solids

This is the key for how to use architecture to cheat and get more ductility out of a material. If you take a brittle material and make a nanoscale lattice or foam out of it, . The new tougher “architected material” can also have a larger plastic zone size, sometimes as much as 100 times larger, meaning it is likely to be ductile as well. This is why things like fabrics and meshes can be really hard to tear.Ěý

How are you applying what you’re learning to real-world materials?

LM: We’re building lots of our material architectures painstakingly at the small scale using resources like the and the UW . That “bottom-up” approach — building things one nanofeature at a time — gives us lots of control over the building blocks we’re playing with, but it’s a real challenge to scale.

The “top-down” approach, where you let physics and kinetics just self-assemble things for you, is much easier. One example is “solid state foaming”, a technique my colleague has been working on for decades. Basically, you take a thermoplastic material — something that melts when you heat it up — throw it in a chamber with high pressure carbon dioxide so it saturates the sample, then heat it up so that dissolved gas forms tiny bubbles in the material. With this process we have less control over the precise architecture — it’s a random foam — but by controlling the amount of dissolved gas we can easily control the size of the bubbles. Those materials turned out to be super tough! My doctoral student has , where we show they could even be tougher than the material they were made from. This goes against everything we knew about normal foam fracture processes.Ěý

A black and white image showing a dense, webbed material.
A black and white image showing a dense, webbed material.
A black and white image showing a dense, webbed material.

A plastic nanofoam material created by Kush Dwivedi, a doctoral student in Meza’s lab, seen at 2,500x, 12,000x and 35,000x magnifications. Credit: Dwivedi et. al/Journal of the Mechanics and Physics of Solids.

I’m currently pursuing an earlier-stage commercialization effort to use tiny foams as a filtration material for biomedical applications. We can make nanoporous filter materials — think of the reverse osmosis system that might be under your sink — but we can do it without using any of the harsh chemical processes that are currently used. We’ve been able to explore this avenue thanks to our participation in the program, which then enabled us to get a award.

I also recently got an NSF CAREER grant to study fracture in architected materials, and we’re exploring ways to make tougher sustainable and biodegradable materials. Think of the last time you used a biodegradable fork that broke off in your food. Materials like wood are actually great alternatives for this, but we’re trying to figure out how to do it without cutting down a tree or harvesting bamboo.Ěý

For more information contact Meza at lmeza@uw.edu.

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