In 2007, a piece of space debris punched a bullet-like hole through the radiator panel of the US space shuttle Endeavor. The shuttle program ended in 2011, but the space debris problem has only intensified as we launch more and more satellite constellations, telescopes, and spacecraft into orbit. That's why Chinese scientists have devised a new aluminum material inspired by eggshells that they believe could offer enhanced protection against debris fragments, according to a new paper published in the Journal of Applied Physics.

Eggshells have long fascinated scientists because of their mechanical properties. For instance, it's well known that cracking an egg requires applying just enough force to the center to achieve a clean break without completely shattering the shell. In 2012, MIT mechanical engineer Pedro Reis co-authored a paper demonstrating the link between an egg's ovoid geometry and its rigidity, a major factor when predicting how much force an object can endure before cracking. (As I wrote for Slate at the time, rigidity is related to, but distinct from, strength. If one eggshell has tiny cracks and the other doesn't, both shells have different strengths—the cracked one will break more easily—but the same rigidity.)

Reis started studying eggshells after participating in a popular physics demonstration: walking on cartons of eggs without breaking them. The key, he learned, was to align the eggs with their narrow tip (the most crack-resistant part) pointing up, and then carefully place one's feet to distribute one's weight over the entire surface area. This ensures that no single egg is overloaded. While it takes around 5.5 pounds of force to crack an egg, that depends on the direction in which the force is applied, as well as its distribution over the shell's surface.

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Snails are well-known for their mucus. The slime is highly valued as an anti-inflammatory and anti-aging ingredient in certain skin care products, and snails can secrete different kinds of mucus with properties tailored to specific functions. A team of German scientists has determined a recipe for how snails achieve that so-called tunability: Collagen and calcium work in tandem to achieve the varying mechanical properties, according to a new paper in the journal Science.

Snail mucus is mostly water; it's the mucins (glycoproteins) and complex carbohydrates that give it that slimy, viscous texture. In addition to cosmetics, the mucus holds great potential for drug delivery. In 2020, scientists found that combining snail slime from a common garden snail with gold nanoparticles helped accelerate wound healing and exhibited anti-inflammatory properties in mice. Most relevant to this latest paper is a 2023 study on garden snail slime that identified three distinct types of secreted mucus: a hydrating version to protect its skin, one that acts as an adhesive glue, and a third that serves as a lubricant so the snail can more easily glide across a surface.

The team focused their research efforts on the grove snail/lemon snail (Cepaea nemoralis), which they deemed well-suited as subjects because the snails secrete five different kinds of mucus with distinct functions. As with the garden snails, there is one that acts as a lubricant to help with locomotion and an adhesive mucus to help the snail stick to various surfaces. Then there's a mucus layer known as the epiphragm that the snail secretes when it hibernates in winter, which contains calcite and effectively seals the shell to protect the snail from predators and harsh environmental conditions.

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Human eyes don’t register the infrared portion of the light spectrum because infrared photons don't carry enough energy to trigger the signaling pathway inside our light-sensing cells. But we’ve been able to make devices that give us a visual representation of what’s happening in the infrared.

A team at the Beijing Institute of Technology, led by Xin Tang and Ge Mu, has now built a device that lets people see infrared in a new way. Instead of just translating it to visible shades of green as it’s done in standard night-vision goggles, it translates different infrared wavelengths into distinct parts of the visual spectrum, giving the eye something closer to natural vision.

Researchers achieved that by combining mercury telluride colloidal quantum dots, which absorb infrared light, and a dual-layer OLED, which converts that absorbed energy into visible color. Stacked together with the right internal wiring, they make incoming infrared radiation come out the other side as an ordinary-looking, full-color image.

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