Materials

Natural beetle juice outperforms Teflon as a lubricant

Natural beetle juice outperfor...
Researchers have found a promising natural lubricant excreted in the knee joints of darkling beetles
Researchers have found a promising natural lubricant excreted in the knee joints of darkling beetles
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Researchers have found a promising natural lubricant excreted in the knee joints of darkling beetles
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Researchers have found a promising natural lubricant excreted in the knee joints of darkling beetles
A scanning electron microscope image shows a strange semi-solid lubricant oozing from the pores in a beetle's knee
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A scanning electron microscope image shows a strange semi-solid lubricant oozing from the pores in a beetle's knee
Scanning electron microscope images highlight the tiny pores on the beetle's knees
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Scanning electron microscope images highlight the tiny pores on the beetle's knees
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No matter how good a design humans have come up with, chances are nature has beaten us to it, and done a better job to boot. The latest innovation to join that list is lubricant, with researchers discovering that beetles naturally lubricate their knees with a strange substance that works better than Teflon.

For vertebrates like us, joints are internal, so they can be neatly encased in liquid lubricants. But that’s not the case with insects – having exoskeletons means their joints are exposed to the outside air. Exactly how they keep them lubed up has remained largely unexplored.

So for the new study, researchers at the Christian-Albrechts University of Kiel and Aarhus University wanted to find out. The team examined the knees of the darkling beetle under a scanning electron microscope, and found that the area where the femur and tibia meet is covered with pores, which excrete a lubricating substance.

The team conducted chemical analysis of the substance and found that it’s mostly made up of proteins and fatty acids. Next, they tested the material as a lubricant, placing it between two glass surfaces and rubbing them together at speeds, loads and pressures that would be in the range of a beetle’s regular walking.

A scanning electron microscope image shows a strange semi-solid lubricant oozing from the pores in a beetle's knee
A scanning electron microscope image shows a strange semi-solid lubricant oozing from the pores in a beetle's knee

And sure enough, the coefficient of sliding friction was much lower for the beetle lube than for two glass plates with no lube. The natural stuff outperformed vacuum grease by a wide margin, and even narrowly pipped polytetrafluoroethylene, commonly known as Teflon.

The beetle juice had some other strange properties too. It’s not a liquid exactly, but more of a “semi-solid.” When it’s extruded from the pores, it tends to fragment easily, which seems to help it cover a wider area more efficiently and penetrate into small gaps.

The team says that this natural lubricant could be useful for small-scale robots and prosthetics, for which conventional lubricants aren’t particularly well-suited. While it’s not exactly practical to try to farm the lube from live beetles, the work could lead to new synthetic versions inspired by the real thing.

The research was published in the journal Proceedings of the Royal Society B.

Source: Nature via New Scientist

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4 comments
4 comments
akarp
Synthetic biology is and will continue to produce more amazing products.
Kpar
When you said "beetlejuice" I thought you were referring to the mayor of Chicago.
Worzel
I could use some ''beetle juice'' for my own creaky knees! When it breaks up into particles, maybe it behaves like 'sticky' ball bearings?
However, there's also the comedy movie associated with it. https://en.wikipedia.org/wiki/Beetlejuice.
ljaques
Wow, fascinating. I hope that is soon produced, and hits the market at a reasonable price point. // And, yeah, Lori looks like something which lived and died long ago on Betelgeuse.