Among the many enduring images of Hurricane Harvey’s 2017 devastation in Houston was the reminder that when faced with floodwaters, fire ants will assemble in groups of up to 100,000 and link their legs together to create nearly watertight rafts that can span several square feet. The venomous red hexapods then collectively float to safety before releasing and continuing their important work as backyard terrorists.
Now researchers at Texas A&M have drawn inspiration from the phenomenon and mimicked it to develop synthetic materials that can autonomously assemble, disassemble, and reconfigure in response to different conditions, such as changes in light or heat. Professor Taylor Ware of A&M’s biomedical and materials science engineering programs, one of the authors of the study published in Nature Materials, says he has been fascinated by fire ants since long before he was an engineer. Today he imagines applications of his research in, among other things, “assistive devices” in the human body. An “implantable artificial sphincter for urinary incontinence,” for instance, could change shape and then reverse itself according to conditions, he suggests.
Ware’s research is part of the growing discipline of biomimicry, in which science imitates nature. Researchers are “taking different lessons from nature into the labs and mimicking those structures to produce unique materials and devices for the benefit of society,” in the words of Raman Chintalapalle, a professor of Aerospace and Mechanical Engineering at the University of Texas at El Paso and director of the university’s Center for Advanced Materials Research.
There’s nothing particularly new about biomimicry, but it has been on the rise over the past decade. Chintalapalle explains that, as technology has emerged to allow researchers to see and understand smaller structures than ever before, it has opened new horizons for things they can create as a result. “Whereas before we couldn’t go below the atomic or molecular level,” he says, “now we can create structures at nano- or even sub-nanoscale,” a size that’s not visible to the human eye.
A few months before the publication of the A&M fire ant study, in April 2023 a team led by Chintalapalle published research inspired by another famously tough Texas resident: the prickly pear. Outside Chintalapalle’s lab was a prickly pear that he and his colleagues walked by every day. “We would see the plant in extreme high temperatures and high winds, and one day we started asking what made it withstand those conditions,” he says. They realized that the structure of the prickly pear—its plate-like paddles, its spherical fruit—maximized the plant’s surface area and therefore its ability to absorb moisture and form tight bonds.
At the time, the team was studying how to use nickel as a catalyst in the process of breaking down water into hydrogen for the development of alternative fuel, and the researchers determined that if they mimicked the physical shape of a prickly pear at nanoscale, they could potentially create a cost-efficient catalyst for the chemical reaction. Hydrogen fuel has long been a dream of the alternative-energy community, but nobody has been able to develop it efficiently enough to be commercially viable. While it’s still too early to declare success, Chintalapalle is optimistic about the prospect of landing funding to do follow-up studies, given the wide interest his team’s work has found.
Chintalapalle and Ware are both quick to point out that Texas is not alone as a rich source for biomimicry ideas. But the resilience and adaptability required of organisms in our harsh environment is certainly useful. Drought, extreme heat, severe freezes, floods: Texas’s climate has it all, and the tenacious animals, plants, and ecosystems that endure here offer survival strategies worth learning from and imitating. “We tend to focus on mimicking the really wonderful things in nature, like butterfly wings,” says Ware. “But it’s also maybe worth mimicking some of the things that we don’t find so interesting in nature, that are still wonderfully useful, like the behaviors of fire ants.”
Plus, Texas offers an impressively wide variety of environments from which to draw inspiration. “The majority of the country doesn’t have extreme environments like the desert in far West Texas, but also the Gulf beaches around Corpus Christi,” Chintalapelle points out. That’s not to mention the bayou country east of Houston or the windswept plains of the Panhandle. All of which adds up to “Texas institutions looking at these things quite heavily,” he says.
Desert plants aren’t the only kind scientists are learning from. In 2018, a UT-Dallas team began to develop a way to harvest water from the air by imitating carnivorous pitcher plants, which grow in the wetlands of East Texas, such as in the Big Thicket National Preserve. The Dallas Morning News compared the resulting process to that of the Skywalker family’s moisture farm on the desert planet of Tatooine in Star Wars. Previous researchers had focused on Namibian desert beetles’ ability to trap and direct water droplets, but the UTD findings offered a more flexible solution that can work on larger or smaller surfaces.
More recently, in 2022, the same research team, led by mechanical engineering professor Xianming “Simon” Dai, published a study that demonstrated a way to accelerate the pitcher plant–inspired water-harvesting process and make it possible for anyone to have a portable water-harvesting device that requires no external energy. That’s a potential game changer for military combat units or other groups who need to survive in the wild for lengthy periods with minimal supplies.
Whereas Chintalapalle’s and Ware’s projects re-create natural phenomena from the human-scale world and translate them at the smallest levels, Dai’s work goes the other direction, scaling a small process up. Professor Astrid Layton, of Texas A&M’s mechanical engineering department, has taken a similar approach, though she focused not on a single species but on the way nature works as a whole. Layton’s 2022 study published in IEEE Transactions on Power Systems mimics the structure of natural systems to design more resilient power grids—something that anyone who’s been a Texan for more than three years can appreciate.
As the authors wrote, dryly, in the study, “Recent disasters have highlighted that a focus on minimizing cost can result in a fragile system, such as the immense economic loss and adverse societal impacts after the 2021 Texas Winter Storm.”
While most human-designed networked systems optimize for efficiency, Layton surmised, nature-designed networks such as ecosystems and biological systems are built around redundancies—which makes them less fragile in the face of unforeseen disruptions. Most approaches to power-system resilience focus on getting the system back up and running after a disturbance, but Layton’s approach instead focuses on the structure of the network in the first place. And while building redundancy into a network inevitably costs more up front, the study concluded it could offset that cost in the event of a disaster.
Layton’s study also hints at the limits of biomimicry. “There’s no shortage of organisms that are interesting to mimic,” says Ware. And with hotter summers and more extreme storms increasingly becoming the norm in Texas, the need for humans to learn from the natural world’s adaptability will only grow—until it can’t. When nature faces its own limits of adaptability and resilience in the face of a changing environment, engineers will have to find inspiration elsewhere.
