Tag Archives: Coated

The teeth of Komodo dragons are coated with iron.

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The Komodo dragon is a ferocious predator.

Charlotte Ellis/Zoological Society of London

Komodo dragons, some of the most ferocious reptiles on Earth, strengthen their teeth with iron caps, and researchers believe some dinosaurs may have had this adaptation as well.

Komodo dragon (Komodo dragon coati) is endemic to several Indonesian islands and preys on larger animals such as deer, pigs, and buffalo; it can grow to three meters in length and weigh up to 150 kilograms.

When I noticed that the animal had orange serrations on its teeth, Aaron LeBlanc The researcher, from King's College London, says he initially dismissed it as staining: “It wasn't until I visited the museum collection and saw all the teeth along the skulls of many Komodo dragon specimens that I became convinced I was looking at a new adaptation for this iconic reptile,” he says.

LeBlanc and his colleagues used high-powered x-rays at a synchrotron facility to examine the surfaces of Komodo dragon teeth and identify the different elements found along the teeth.

“When we mapped the cross-sections of Komodo dragon teeth, we quickly saw that iron was concentrated at the cutting edge and tip of the tooth, but not anywhere else in the tooth,” LeBlanc says, “and this matches up exactly with the orange stains we see on the teeth under a microscope.”

Komodo dragon tooth with orange steel cap

Dr Aaron LeBlanc, King's College London

Komodo dragon enamel is incredibly thin compared to human teeth, LeBlanc said: At the serrated edge, the enamel is just 20 micrometers thick, about a quarter of the thickness of a human hair. Human tooth enamel is about 100 times thicker.

The iron coating on Komodo dragon teeth is coated on top of this extremely thin layer of enamel, which the team believes gives the enamel extra strength, protects the serrations as the dragon eats its prey, or acts as a barrier against acidic digestive juices.

Iron is readily available in the environment, especially for large carnivores, and it's thought that the cells that make enamel change their behavior towards the final layer, producing an iron-rich finish.

Crocodiles and alligators can also concentrate iron in their enamel, but their teeth do not have iron-rich crowns.

The researchers also looked for iron coatings on the dinosaur fossil teeth. They haven't found evidence yet, but the researchers think that could be because the iron signal was destroyed by fossilization. “We need to look at better preserved dinosaur teeth to be sure,” LeBlanc said.

Leblanc says his fellow dentists are intrigued by the potential of these natural materials: “It's still a long way off, but I can imagine a time when we develop new enamel coatings inspired by nature, perhaps even the Komodo dragon,” he says.

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Source: www.newscientist.com

New Glasses Coated with Lithium Enhance Vision in Low Light

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A device that can convert infrared light into visible light

Laura Valencia Molina et al. 2024

Glasses coated with lithium compounds may one day help us see clearly in the dark.

For more than a decade, researchers have been searching for the best lightweight materials that can convert infrared light, invisible to the human eye, into visible light in order to provide an alternative to night-vision goggles, which are often heavy and cumbersome.

Until recently, the leading candidate was gallium arsenide. Laura Valencia Molina The researchers, from the Australian National University in Canberra, and their colleagues found that a film of lithium niobate coated with a lattice of silicon dioxide performed better.

“Through improved design and material properties, we have achieved a tenfold increase in the conversion rate from infrared to visible light compared to gallium arsenide films,” the team said. Maria del Rocio Camacho MoralesAt the Australian National University.

Through a series of experiments, the team demonstrated that the lithium niobate film could convert high-resolution images from infrared light with a wavelength of 1,550 nanometers to visible light with a wavelength of 550 nanometers, exceeding the capabilities of gallium arsenide.

Night vision goggles require infrared particles called photons to pass through a lens and be converted into electrons in a device called a photocathode. These electrons then pass through a phosphor screen to be converted into visible light photons. This entire process requires cryogenic cooling to prevent distortion of the image.

Molina says the lithium niobate film is hit by infrared light emitted by an object and illuminated with a laser at the same time. The film combines the infrared light with the laser light, which then up-converts the infrared light into visible light.

Camacho Morales says that one day, lattices of lithium niobate and silicon dioxide could be made into a film thinner than plastic wrap that could be coated over regular glasses to improve night vision.

While still in the research stage, the laser was positioned so that it could be easily shone onto the film along with infrared light emitted by the object, and the team is now experimenting with creating an array of nanolasers that can be positioned on top of the lithium niobate film.

The research is an important next step toward lightweight night-vision devices, and perhaps a film that can be attached to ordinary glasses, Camacho Morales said. It could also help drones navigate in the dark, he said, because current night-vision devices are too heavy to carry in some vehicles.

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Source: www.newscientist.com