The jaws of some sea worms are made of an exceptionally hard yet lightweight material dubbed a “bio-metal” that could have applications in engineering.

Perinereis cultrifera is a type of ragworm with a long body adorned with bristles. Members of the species also have strong jaws that enable them to crush hard prey such as small crustaceans or other worms. Remnants of their jaws have been found in the fossil record dating back to hundreds of millions of years ago.

at TU Wien in Austria and his colleagues have been studying this worm’s jaws for almost a decade, leading them to propose that they are made of a novel material. The molecular structure of each jaw combines proteins and ions of metals such as zinc, giving it characteristics in between those of softer biological materials and metals.

Most recently, the team performed more than 3300 experiments in which small indentations were made in different parts of the jaw. The way its hardness changed under this pressure followed a pattern typical of metals like copper and silver. But the jaw also exhibited a kind of elasticity that metals cannot have, says Hellmich.

Finally, the researchers developed a mathematical model of bio-metals, which shows how they might respond to strain in a unique way in which microscopic forces arise from the metal ions becoming arranged into lines similar to certain defects in crystals.

Free newsletter

Sign up to The Earth Edition

Sign up to newsletter

The researchers were surprised to uncover so much novelty in the relatively simple animal. Performing mechanical tests on the millimetre-sized jaw was really challenging and required hundreds of hours of preparation and polishing, says Hellmich. “Basically, anything can go wrong,” he says.

“The jaws of bristle worms are incredibly hard yet very lightweight,” says at Kent State University in Ohio. “Many industries, from automobiles to aeronautics, are searching for new ways to develop hard and lightweight materials. The answers are provided in nature!”

“Somehow evolution figured out a way to coax a metal-like mechanical fingerprint out of protein-like ingredients, and studying the worm is how we ask what trick makes that possible,” says at the Massachusetts Institute of Technology, who didn’t work on the study. The long-term dream outcome of this research is to genetically program materials that would grow in biological systems, he says.

Hellmich and his colleagues are interested in pursuing this goal and their team already includes geneticists and biologists at the University of Vienna. “We are asking questions like, ‘If we knock out a few genes, then how will the jaws be different?’” he says.

A new quantum state of matter behaves as if it doesn’t fully belong to a world with two or three dimensions of space, revealing a previously unobserved way for electrons to move.

Physicists categorise states of matter based on how electrons move within a material. This motion depends on many factors, such as the arrangement of the material’s atoms.

When a thin material is immersed in a magnetic field, its electrons trace tiny circles, and any stream of them is pushed to the material’s side. This is known as the Hall effect. For materials that are magnetic, electron choreographies become more complex, giving rise to different versions of this effect.

at Nanjing University in China and his colleagues unexpectedly discovered a new version of this phenomenon, which they call the transdimensional anomalous Hall effect (TDAHE).

The team was studying electrons in a made from carbon atoms arranged in a pattern of hexagons in hopes of seeing them form perfectly efficient currents. But when they immersed the material in a magnetic field, the electrons reacted oddly.

“TDAHE came about as a complete surprise, a phenomenon never seen in any other material before, nor does any theory predict that,” says Wang. “After we measured the raw data, we spent about one year [trying] to understand it.”

Subscriber-only newsletter

Sign up to Lost in Space-Time

Sign up to newsletter

Specifically, what stumped the researchers was that their material exhibited a type of Hall effect when they applied two different, mutually perpendicular magnetic fields. This means the electrons could execute looping motions both horizontally and vertically, even though the material was supposed to be too thin to accommodate both.

Wang says he and his colleagues initially thought some experimental error was to blame, but several follow-up experiments kept confirming that their measurements were correct. Making and testing more samples of the materials showed the same. They had to conclude that for pieces of their carbon material between 2 and 5 nanometres thick, the electrons were simply doing something new.

Because these thicknesses don’t make the material fully two- or three-dimensional, the team named the new electronic state accordingly. It doesn’t somehow bridge two- and three-dimensional realms, says Wang. “It is also not a little bit of 2D and another little bit of 3D. By using ‘transdimensional’, we want to express that there exists a new regime, which does not belong to previously well-studied 2D or 3D cases,” he says.

Solving the 250-year-old puzzle of how static electricity works

You may think you know static electricity, but its true nature has long eluded scientists. We’ve now made a huge leap towards finally figuring it out

at the University of California, Santa Barbara, says that what sets the new state apart is that the mathematical representation of the electrons’ states lacks symmetry in three different ways, which is novel compared with similar states. In his view, this is more of a defining feature than the dimensionality of the material – its thickness is just a means to an end, he says.

Young says the new state can be thought of as a type of “quarter-metal”, or a metal where the lack of symmetry limits what the electrons can do compared with more conventional metals.

Wang’s team now wants to look for what they term transdimensional physics in other materials and to use more instruments, such as diamond-based magnetic field sensors, to learn more about the new state.

These days, our lives revolve around the digital world. Money, culture, news, gossip – all of it lives there. Generative artificial intelligence is the biggest story in the world, but could you point to where that technology is physically located? The material world just isn’t where the action is.

And yet, despite appearances, we still live in a material world. We need steel for building, lithium and cobalt for batteries, and (despite our best efforts) oil to power our vehicles. Materials might not be sexy, but they still undergird our way of life and shape world events.

We may now be on the cusp of something radical: a completely new way to understand materials. History teaches us that the consequences could be huge. The last time we had such a groundbreaking idea in materials science, it was the late 1920s, with discoveries about the way electrons occupy particular energy levels – or bands – and the gaps between them. This presaged the development of the transistor, the basic unit of all computer hardware, including the chips that power modern AI.

But researchers have long suspected that the innards of materials contain more than those simple energy bands. They may also have a subtle, undulating quantum topography that could determine their properties. And as we report in our cover feature (see “We’ve glimpsed the secret quantum landscape inside all matter”), we are now charting this quantum landscape for the first time.

Materials may have a subtle, undulating quantum topography

This deeper exploration could lead to discoveries as revolutionary as the transistor. One hope, for example, is a material that conducts electricity with zero resistance at room temperature.

Finding one of these superconductors would mean we could transmit electricity with no loss in power, a serious boon to green energy and our fight against climate change, among other things.

Even better, this probing could lead us to some new kind of material that we haven’t foreseen at all. Far from retreating from the material world, we might be on the brink of expanding its horizons.