COLUMBUS, OhioHigh hopes may help move a rubber tree plant (as the old song goes), but the real secret to the ant's legendary strength may lie in its tiny neck joint.
In the Journal of Biomechanics, researchers report that the neck joint of a common American field ant can withstand pressures up to 5,000 times the ant's weight.
"Ants are impressive mechanical systemsastounding, really," said Carlos Castro, assistant professor of mechanical and aerospace engineering at The Ohio State University. "Before we started, we made a somewhat conservative estimate that they might withstand 1,000 times their weight, and it turned out to be much more."
The engineers are studying whether similar joints might enable future robots to mimic the ant's weight-lifting ability on earth and in space.
Other researchers have long observed ants in the field and guessed that they could hoist a hundred times their body weight or more, judging by the payload of leaves or prey that they carried. Castro and his colleagues took a different approach.
They took the ants apart.
"As you would in any engineering system, if you want to understand how something works, you take it apart," he said. "That may sound kind of cruel in this case, but we did anesthetize them first."
The engineers examined the Allegheny mound ant (Formica exsectoides) as if it were a device that they wanted to reverse-engineer: they tested its moving parts and the materials it is made of.
They chose this particular species because it's common in the eastern United States and could easily be obtained from the university insectary. It's an average field ant that is not particularly known for it's lifting ability.
They imaged ants with electron microscopy and X-rayed them with micro-computed tomography (micro-CT) machines. They placed the ants in a refrigerator to anesthetize them, then glued them face-down in a specially designed
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Ohio State University