Moving at speeds thousands of times faster than the blink of an eye, an ant’s spring-loaded jaws capture the insect’s prey by surprise and can also release the ant into the air if it aims its force at the ground. Now, scientists have revealed how an ant’s jaw can close very quickly without being shattered by force.
In a new study published Thursday (July 21) in the newspaper Journal of Experimental Biology (Opens in a new tab)a team of biologists and engineers studied a type of jaw-trap ant called Odontomachus brunneusIt is native to parts of the United States, Central America, and the West Indies. To build strength for lightning-fast bites, the ants first extend their jaws apart, forming a 180-degree angle, and strike them against the latches inside their heads. enormous muscles, connected to each jaw by a tendon-like cord, pull the jaws in place and then flex to build up a store of elastic energy; The team found that this flexion is so severe that it twists the sides of the ant’s head, causing it to bend inward. When an ant strikes, its jaw opens and that stored energy is released at once, smashing the jaws together.
The researchers examined this spring-loaded mechanism in fine detail, but project engineers puzzled how the system could operate without generating much friction. Friction will not only slow down the jaws, but will also cause devastating wear at every point of rotation of the jaw. Using mathematical modeling, they finally found an answer for how jaw ants avoid this problem.
“That’s the part that engineers are incredibly excited about,” partly because the discovery could pave the way for building tiny robots that can spin their parts with unparalleled speed and precision, Sheila Patek, a professor of biology at Duke University at Duke University in Durham, North Carolina, the study’s senior author, told Live Science.
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Virtually frictionless spring-loaded system
To study incredible jaws Hey PrunosPatek and her colleagues collected ants from a colony found in the bushes near Lake Placid, Florida. Back in the lab, the team dissected some ants and took detailed and micro-measurements.CT scan of their body parts, in particular the jaws, muscles and the external structure of the head. They later incorporated these measurements into their mathematical models of ant movements.
In addition, the team put some ants in front of a high-speed camera that captures stunning shots at 300,000 frames per second. (Video is typically shot at 24 to 30 frames per second, for comparison.) These videos revealed that, as the ants prepared to strike, the exoskeleton covering their heads underwent significant stress, shortening by about 3%, length, and growing. About 6% are skinny around the middle. This pressure occurred over several seconds, Patek said, which is a slow feeling compared to the rapid bite of an ant.
Once freed from the latches, the ant’s jaws swung through a perfect arc, peaking at around the 65-degree mark before starting to slow. In the fastest time, the tips of the ants’ jaws traveled about 120 mph (195 km/h) into the air.
The team determined that this ultra-fast motion unfolds smoothly and precisely thanks to the many forces acting on the jaws at the same time.
First, when the ant’s head returned to its normal shape, the tip of each jaw jumped out into space. Meanwhile, the large muscles inside the ant’s head relaxed and stopped tightening the tendon-like cords that were attached to it. As each rope settled to its normal length – think of an elongated rubber band being suddenly released – it was yanked off at the end of the jaw located inside the ant’s head. It was this simultaneous push and pull that caused the ants’ jaws to fly toward each other.
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A similar principle applies when you spin a bottle on a flat surface; The twisting motion required to rotate the bottle involves pushing one end of the bottle forward while pulling the other end back. Similarly, when ballerinas perform a small role with the support of a partner, the partner pushes one hip forward and pulls the other back to make the turn in the movement. However, the best analogy to the movement of the lower jaw of the jaw ant might be that of stick juggling, a circus art in which performers use sticks to spin a stick in the air.
The stick experiences little friction as it flips through the air, and based on their mathematical models, the study authors believe that the lower jaw of the anthills is similarly unconstrained. At first, researchers thought that each jaw might rotate around a pin hinge, similar to a door on a hinge, but they decided that such a structure would offer a great deal of resistance. Instead, they found, the jaws orbited around a less rigid articulated structure that required little reinforcement in the ant’s head.
“The double-spring mechanism greatly reduces the interaction and friction forces in this joint so that the joint does not need as much reinforcement in order to hold the lower jaw in place,” said study co-first author Gregory Sutton, a research fellow of the Royal Society at the University of Lincoln in England, she told Live Science in an email. The authors conclude that the lack of friction in this system may explain how jaw ants can strike over and over without ever hurting themselves.
The authors believe that all ants trap in Sunni Patek said the genus uses the same spring-loaded mechanism for biting, but titular ants in other species may use a slightly different strategy. However, Patek suspects that the mechanism they discovered may be used by other arthropods, namely insects, spiders and crustaceans.
for example, mantis shrimpFamous for throwing 50 mph (80 km/h) punches, it likely deforms their exoskeletons and uses super-stretched tendons to build strength for each punch – although this mechanism has yet to be identified in shrimp.
“We’re starting to realize that’s going to be the general rule for these ultra-fast arthropods,” Patek said.
Originally published on Live Science.