Click beetles can propel themselves more than 20 body lengths into the air, and they do so without using their legs. While the jump’s motion has been studied in depth, the physical mechanisms that enable the beetles’ signature clicking maneuver have not.
A new study examines the forces behind this superfast energy release and provides guidelines for studying extreme motion, energy storage and energy release in other small animals like trap-jaw ants and mantis shrimps. The research team used the resources of the Advanced Photon Source (APS), a U.S. Department of Energy (DOE) Office of Science User Facility at DOE’s Argonne National Laboratory, to capture images of the phenomenon in live beetles.
“If an engineer wanted to build a device that jumps like a click beetle, they would likely design it the same way nature did.” — Aimy Wissa, University of Illinois at Urbana-Champaign
The study was published in the Proceedings of the National Academy of Science. It was led by University of Illinois at Urbana-Champaign mechanical science and engineering professors Aimy Wissa and Alison Dunn, entomology professor Marianne Alleyne and mechanical science and engineering graduate student and lead author Ophelia Bolmin.
“Many animals, such as these click beetles, can significantly amplify their mechanical power by using springs and latches,” said Kamel Fezzaa, a physicist in Argonne’s X-ray Science Division and an author on the paper. “They do it repeatedly without noticeable damage to their bodies. This study opens the door to a better understanding of the dynamics of such mechanisms. Such insights may lead to the design of power-amplified engineered systems that are efficient and resilient to wear and tear.”
Many insects use various hook-, latch- and spring-like mechanisms to overcome the limitations of their muscles. However, unlike other insects, click beetles use a unique hinge-like tool in their thorax, just behind the head, that they use to jump.
“The hinge mechanism has a peg on one side that stays latched onto a lip on the other side of the hinge,” said Alleyne. “When the latch is released, there is an audible clicking sound and a quick unbending motion that causes the beetle’s jump.”
Seeing this ultrafast motion using a visible-light camera helps the researchers understand what occurs outside the beetle. Still, it doesn’t reveal how internal anatomy controls the flow of energy between the muscle, other soft structures and the rigid exoskeleton.
To determine how the hinge works, the team used high-speed X-rays at beamline 32-ID of the APS to observe and quantify how a click beetle’s body parts move before, during and after the ultrafast energy release.
“The beam we used for these experiments is as clean as it gets, meaning no optics are used before the actual detector,” Fezzaa said. “It comes straight from our source, at an energy that is a sweet spot for high-speed live imaging of insects. Our beamline is equipped with state-of-the-art high-speed imaging instrumentation, including intense beams and fast shutters, timing equipment and detectors.”
Using the X-ray video recordings and an analytical tool called system identification, the team identified and modeled the clicking motion forces and phases. John Socha, professor of biomechanical engineering at Virginia Tech, helped collect the high-speed X-ray videos that enabled the discoveries in this paper.
The researchers observed large, yet relatively slow deformations in the soft tissue part of the beetles’ hinge in the lead-up to the fast unbending movement.
“When the peg in the hinge slips over the lip, the deformation in the soft tissue is released extremely quickly, and the peg oscillates back and forth in the cavity below the lip before coming to a stop,” Wissa said. “The fast deformation release and repeated, yet decreasing, oscillations showcase two basic engineering principles called elastic recoil and damping.”
The acceleration of this motion is more the 300 times that of the Earth’s gravitation acceleration. That is a lot of energy coming from such a small organism, researchers said.
“Surprisingly, the beetle can repeat this clicking maneuver without sustaining any significant physical damage,” Dunn said. “That pushed us to focus on figuring out what the beetles’ use for energy storage, release and dissipation.”
“We discovered that the insect uses a phenomenon called snap-buckling — a basic principle of mechanical engineering — to release elastic energy extremely quickly,” Bolmin said.
“We were surprised to find that the beetles use these basic engineering principles,” Wissa said. “If an engineer wanted to build a device that jumps like a click beetle, they would likely design it the same way nature did. This work turned out to be a great example of how engineering can learn from nature and how nature demonstrates physics and engineering principles.”
About the Advanced Photon Source
The U. S. Department of Energy Office of Science’s Advanced Photon Source (APS) at Argonne National Laboratory is one of the world’s most productive X-ray light source facilities. The APS provides high-brightness X-ray beams to a diverse community of researchers in materials science, chemistry, condensed matter physics, the life and environmental sciences, and applied research. These X-rays are ideally suited for explorations of materials and biological structures; elemental distribution; chemical, magnetic, electronic states; and a wide range of technologically important engineering systems from batteries to fuel injector sprays, all of which are the foundations of our nation’s economic, technological, and physical well-being. Each year, more than 5,000 researchers use the APS to produce over 2,000 publications detailing impactful discoveries, and solve more vital biological protein structures than users of any other X-ray light source research facility. APS scientists and engineers innovate technology that is at the heart of advancing accelerator and light-source operations. This includes the insertion devices that produce extreme-brightness X-rays prized by researchers, lenses that focus the X-rays down to a few nanometers, instrumentation that maximizes the way the X-rays interact with samples being studied, and software that gathers and manages the massive quantity of data resulting from discovery research at the APS.
This research used resources of the Advanced Photon Source, a U.S. DOE Office of Science User Facility operated for the DOE Office of Science by Argonne National Laboratory under Contract No. DE-AC02-06CH11357.
Argonne National Laboratory seeks solutions to pressing national problems in science and technology. The nation’s first national laboratory, Argonne conducts leading-edge basic and applied scientific research in virtually every scientific discipline. Argonne researchers work closely with researchers from hundreds of companies, universities, and federal, state and municipal agencies to help them solve their specific problems, advance America’s scientific leadership and prepare the nation for a better future. With employees from more than 60 nations, Argonne is managed by UChicago Argonne, LLC for the U.S. Department of Energy’s Office of Science.
The U.S. Department of Energy’s Office of Science is the single largest supporter of basic research in the physical sciences in the United States and is working to address some of the most pressing challenges of our time. For more information, visit https://energy.gov/science.