Academics say the material could be used to create unclonable physical components suitable for supporting digital security.
Category: materials – Page 168
A newly created nano-architected material exhibits a property that previously was just theoretically possible: it can refract light backward, regardless of the angle at which the light strikes the material.
This property is known as negative refraction and it means that the refractive index—the speed that light can travel through a given material—is negative across a portion of the electromagnetic spectrum at all angles.
Refraction is a common property in materials; think of the way a straw in a glass of water appears shifted to the side, or the way lenses in eyeglasses focus light. But negative refraction does not just involve shifting light a few degrees to one side. Rather, the light is sent in an angle completely opposite from the one at which it entered the material. This has not been observed in nature but, beginning in the 1960s, was theorized to occur in so-called artificially periodic materials—that is, materials constructed to have a specific structural pattern. Only now have fabrication processes have caught up to theory to make negative refraction a reality.
Iron that rusts in water theoretically shouldn’t corrode in contact with an “inert” supercritical fluid of carbon dioxide. But it does.
The reason has eluded materials scientists to now, but a team at Rice University has a theory that could contribute to new strategies to protect iron from the environment.
Materials theorist Boris Yakobson and his colleagues at Rice’s George R. Brown School of Engineering found through atom-level simulations that iron itself plays a role in its own corrosion when exposed to supercritical CO2 (sCO2) and trace amounts of water by promoting the formation of reactive species in the fluid that come back to attack it.
The photograph was captured by the probe’s WISPR (Wide-field Imager for Solar Probe) instrument when the spacecraft traveled at a distance of 16.9 million miles from the sun, inside our star’s corona.
The image shows distinct jets of solar material, dubbed coronal streamers, seen to the left/center of the image.
The bright spot you see in the above image is Mercury.
The earthen tone of this off-grid holiday home in Northern Mexico was selected to match the rock formations of the nearby Cumbres de Majalca National Park, which is known for its dramatic landscapes.
OAX Arquitectos completed this remote home as a vacation getaway for a large family. It is located within a national park in Mexico’s Chihuahua State, just south of the American border.
“As part of the development of the park, a section was reserved to house cottages, but because of its remote location lacks services,” said OAX Arquitectos, which is based in Monterey.
Researchers created a biocompatible graphene ink and used household printers to make electronic components.
Scientists in Ireland have developed a new low-cost method to produce graphene, which could accelerate adoption of the strong and light ‘wonder material’.
Researchers at Trinity College Dublin’s School of Physics and AMBER, the Science Foundation Ireland research centre for advanced materials, teamed up with colleagues in the UK and Norway to develop a scalable graphene production method.
Advances in the AI realm are constantly coming out, but they tend to be limited to a single domain: For instance, a cool new method for producing synthetic speech isn’t also a way to recognize expressions on human faces. Meta (AKA Facebook) researchers are working on something a little more versatile: an AI that can learn capably on its own whether it does so in spoken, written or visual materials.
The traditional way of training an AI model to correctly interpret something is to give it lots and lots (like millions) of labeled examples. A picture of a cat with the cat part labeled, a conversation with the speakers and words transcribed, etc. But that approach is no longer in vogue as researchers found that it was no longer feasible to manually create databases of the sizes needed to train next-gen AIs. Who wants to label 50 million cat pictures? Okay, a few people probably — but who wants to label 50 million pictures of common fruits and vegetables?
Currently some of the most promising AI systems are what are called self-supervised: models that can work from large quantities of unlabeled data, like books or video of people interacting, and build their own structured understanding of what the rules are of the system. For instance, by reading a thousand books it will learn the relative positions of words and ideas about grammatical structure without anyone telling it what objects or articles or commas are — it got it by drawing inferences from lots of examples.
Machines can now distinguish between 12 different types of plastic, thanks to a new camera system developed in Denmark.
A research team from the University of Waterloo is working on a passive treatment method that enables the removal of arsenic from surface water through a combination of waste materials.
Inspired by the growth of bones in the skeleton, researchers at the universities of Linkoping in Sweden and Okayama in Japan have developed a combination of materials that can morph into various shapes before hardening. The material is initially soft but later hardens through a bone development process that uses the same materials found in the skeleton.
When we are born, we have gaps in our skulls that are covered by pieces of soft connective tissue called fontanelles. It is thanks to fontanelles that our skulls can be deformed during birth and pass successfully through the birth canal. Post-birth, the fontanelle tissue gradually changes to hard bone. Now, researchers have combined materials that together resemble this natural process. “We want to use this for applications where materials need to have different properties at different points in time. Firstly, the material is soft and flexible, and it is then locked into place when it hardens. This material could be used in, for example, complicated bone fractures. It could also be used in microrobots — these soft microrobots could be injected into the body through a thin syringe, and then they would unfold and develop their own rigid bones”, says Edwin Jager, associate professor at the Department of Physics, Chemistry and Biology (IFM) at Linkoping University.
The idea was hatched during a research visit in Japan when materials scientist Edwin Jager met Hiroshi Kamioka and Emilio Hara, who conduct research into bones. The Japanese researchers had discovered a kind of biomolecule that could stimulate bone growth under a short period of time. Would it be possible to combine this biomolecule with Jager’s materials research, to develop new materials with variable stiffness? In the study that followed, published in Advanced Materials, the researchers constructed a kind of simple “microrobot”, one which can assume different shapes and change stiffness. The researchers began with a gel material called alginate. On one side of the gel, a polymer material is grown. This material is electroactive, and it changes its volume when a low voltage is applied, causing the microrobot to bend in a specified direction.