By: Cassidy Delamarter, University Communications and Marketing
Chameleon grabbing bug
The tongues of chameleons and salamanders might not seem like the inspiration for tomorrow's engineering breakthroughs, but inside the Deban Laboratory at the University of South Florida, biology and engineering are colliding to reveal how nature's designs could one day help solve challenges on Earth and beyond.
USF postdoctoral researcher Yu Zeng and integrative biology Professor Stephen Deban's most recent study reveals, for the first time, that salamanders and chameleons - though worlds apart in evolution - use the same underlying mechanism to launch their tongues at lightning-fast speeds.
The discovery, published on the cover of the Sept. 8 edition of Current Biology, not only deepens our understanding of animal movement, but also points toward new potentials inspired by biology.
Chameleons and salamanders live in vastly different habitats - with chameleons living in warmer environments on trees or bushes and salamanders thriving in moist habitats, including in leaf litter and caves.
"They have actually never met each other in the wild," Zeng said. And yet, Zeng and Deban found that both groups developed a remarkably similar "ballistic" tongue-firing system.
"They evolved the same architecture in their bodies to fire their tongues at high speed," Zeng explained. "What's surprising is that they achieve this using the same ordinary tissues, tendons and bone that other vertebrates have."
For Deban, who has studied animal movements and physiology for more than three decades, bringing Zeng into his lab expanded the scope of his research into new, interdisciplinary territory. Zeng, who previously studied insect flight, brought a fresh perspective on how animals move through air and how those insights could translate to technology.
Video analysis, accumulated over more than a decade in Deban's lab, shows that both salamanders and chameleons can project their tongues at speeds of up to 16 feet per second. The study is the first to place these species side by side and reveal a unifying mechanical model.
The tongue mechanism works much like a slingshot. That mechanism is what Deban and Zeng say has big engineering potential beyond the lab, into hospitals, disaster zones and even outer space.
"This mechanism can be scaled up or down, using soft or flexible materials," Zeng said. "We're already talking with engineers about possible biomedical applications, like devices that could clear blood clots. On a larger scale, it could inspire tools to retrieve objects in hard-to-reach places like a collapsed building or even grabbing debris in outer space."
Zeng and Deban in the laboratory
Deban and Zeng plan to expand their research to investigate how animal tongues not only project but also retract with remarkable speed and precision. Their work reflects a growing movement in science called "bioinspiration," which refers to the development of novel materials, devices or structures from solutions found in organisms.
"It is gratifying to have a unifying story about these amazing tongues, as well as potential engineering applications after so many years of focusing on the biology of these animals," Deban said. "Nature has already solved these problems, now we're learning how to adapt those solutions for us."
Undergraduate and graduate research opportunities in the Deban Laboratory
