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Many applications, from fiber-optic telecommunications to biomedical imaging processes require substances that emit light in the near-infrared range (NIR). A research team in Switzerland has now developed the first chromium complex that emits light in the coveted, longer wavelength NIR-II range. In the journal Angewandte Chemie, the team has introduced the underlying concept: a drastic change in the electronic structure of the chromium caused by the specially tailored ligands that envelop it.

Many materials that emit NIR light are based on expensive or rare metal complexes. Cheaper alternatives that emit in the NIR-I range between 700 and 950 nm have been developed but NIR-II-emitting complexes of non–precious metals remain extremely rare. Luminescence in the NIR-II range (1000 to 1,700 nm) is, for example, particularly advantageous for in vivo imaging because this light penetrates very far into tissues.

The luminescence of complexes is based on the excitement of electrons, through the absorption of light, for example. When the excited electron drops back down to its ground state, part of the energy is emitted as radiation. The wavelength of this radiation depends on the energetic differences between the electronic states. In complexes, these are significantly determined by the type and arrangement of the ligands bound to the metal.

Wait, how many stars were at this party? It’s likely there were up to five – but only two appear now! A research team recently began digging into Webb’s highly detailed images of the Southern Ring Nebula to reconstruct the scene. It’s possible more than one star interacted with the dimmer of the two central stars, which appears red in this image, before it created this jaw-dropping planetary nebula. The first star that “danced” with the party’s host created a light show, sending out jets of material in opposite directions. Before retiring, it gave the dim star a cloak of dust. Now much smaller, the same dancer might have merged with the dying star – or is now hidden in its glare.

A third partygoer may have gotten close to the central star multiple times. That star stirred up the jets ejected by the first companion, which helped create the wavy shapes we see today at the edges of the gas and dust. Not to be left out, a fourth star with an orbit projected to be much wider, also contributed to the celebration. It circled the scene, further stirring up the gas and dust, and generating the enormous system of rings seen outside the nebula. The fifth star is the best known – it’s the bright white-blue star visible in the images that continues to orbit predictably and calmly.

The final showstopping finding is an accurate measurement of the mass that the central star had before it ejected its layers of gas and dust. Researchers estimate the star was about three times the mass of the Sun before it created this planetary nebula – and about 60 percent of the mass of the Sun after. It’s still early days – this is some of the first published research about some of Webb’s first images to be released, so plenty more details are sure to come.

I’ve looked at quite a few of the Planck base units, and I’ve even worked them out mathematically, but today I’m going to look at one of the derived units and I’ll compare it to some other things to see how big or small this is. Today then I’m going to be looking at the Planck Density. Let’s find out more.
Before we start, we need to know what density is. Density is a measure of how tightly packed a material is. In other words, how much stuff is packed into a certain volume of space.

To work out density then we need a formula, and units. To work out density we use the following formula, density and that is denoted by the greek letter rho equals mass divided by volume. The SI unit of density is kilograms per metre cubed. So now that we know what density is and we have our units, time to see how dense different materials are and then compare that to the Planck density, which is very dense indeed. At the end I’ll show you where the numbers come from. We’ll start off by looking at some very un dense things and work our way up.

Continue reading “The Planck Density: The Density of the Early Universe” »

“No other study has been able to record optically and electrically at the same time.”

Engineers and neuroscientists at the University of California, San Diego have shown for the first time that mice implanted with human brain organoids have functional connectivity to their cortex and respond to external sensory stimuli.

A novel experimental setup that combines transparent graphene microelectrode arrays and two-photon imaging allowed researchers to make this observation over a period of months in real time. The implanted organoids responded to visual stimuli in the same manner as surrounding tissues, according to the press release.

Tags: 2D Material Angela Hight Walker Brett Goldsmith Caio Lo Sardo Cardea Bio Council Graphene Graphene Council Graphene News MITO Material Solutions Nanotechnologies National Institute of Standard

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Researchers from the Korea Advanced Institute of Science and Technology (KAIST), Pusan National University and CNRS have developed an artificial muscle that is 17 times more powerful than that of humans. The muscle made of graphene-liquid crystal elastomer-based fiber bundles will reportedly be commercialized through a Korean company. Image The main factor that hinders the development of high-performance artificial muscles is that scientists are not able to mechanically select a certain part of the artificial muscle to contract and expand. Large and bulky artificial muscles are not accurate enough.

Researchers at The University of Texas at Austin and Texas A&M University have used electronic tattoo (e-tattoo) technology to measure stress levels, by attaching a device to people’s palms (AKA electrodermal activity or EDA sensing). The researchers created a graphene-based e-tattoo that attaches to the palm, is nearly invisible and connects to a smart watch. Image In June 2022, researchers from the same universities also developed a graphene-based electronic tattoo that can be worn on the wrist for hours and deliver continuous blood pressure measurements at an accuracy level exceeding nearly all available options on the market today.

National University of Singapore researchers advanced the first step towards real-time, remote and wireless mind control of metamaterials.

Finding a material that could replace silicon is a critical task in nanoelectronics. For many years, graphene has appeared promising. However, its potential was compromised along the way because of destructive processing techniques and the absence of a new electronics paradigm to adopt it. The need for the next major nanoelectronics platform is greater than ever, as silicon is almost at its limit in supporting faster computation.

The strength of graphene, according to Walter de Heer, a professor at the Georgia Institute of Technology’s School of Physics, rests in its flat, two-dimensional structure, which is kept together by the strongest chemical bonds known.