https://www.techexplorist.com/scientists-discovered-new-exotic-state-matter-atom-full-atoms/12094/
Atom
IBM seriously just turned an atom into the world’s smallest hard drive.
Data storage technology continues to shrink in size and grow in capacity, but scientists have just taken things to the next level – they’ve built a nanoscale hard drive using a single atom.
By magnetising an atom, cooling it with liquid helium, and storing it in an extreme vacuum, the team managed to store a single bit of data (either a 1 or a 0) in this incredibly miniscule space.
Not enough room for your holiday photos then, but according to the team from IBM Research in California, this proof-of-concept approach could eventually lead to drives the size of a credit card that could hold the entire iTunes or Spotify libraries, at about 30 million songs each.
“We conducted this research to understand what happens when you shrink technology down to the most fundamental extreme – the atomic scale,” says one of the researchers, nanoscientist Christopher Lutz.
The team deployed its Nobel Prize-winning Scanning Tunneling Microscope (STM) for the experiment, which uses the ‘tunnelling phenomenon‘ in quantum mechanics, where electrons can be pushed through barriers, to study electronics at the atomic scale.
With the extreme vacuum conditions inside the STM, free from air molecules and other types of contamination, scientists were able to successfully manipulate a holmium atom.
The microscope also applies liquid helium cooling, which is important in adding stability to the magnetic reading and writing process.
Thanks to that carefully controlled environment, the team could accurately read and write two magnetically charged atoms just a single nanometre apart – that’s one millionth the width of a pinhead.
With the help of the microscope, the scientists could deliver an electric current that turns the magnetic orientation of a single atom up or down, mimicking the operation of a normal hard drive, but on a much smaller scale.
Today’s hard drives use about 100,000 atoms to store a single bit, so you can get an idea of the difference we’re talking about.
The team says the technique could produce drives that are 1,000 times denser than the ones we have right now.
And while the process is going to remain much too difficult and expensive to use commercially for some time, the researchers have shown that it can be done, which is an exciting first step.
This is just the latest in a long line of innovations in data storage – earlier this month researchers from Columbia University announced they’d crammed six digital files into a single speck of DNA.
While there have been previous efforts to store data on single atoms, this is now the smallest and most stable result yet, according to the IBM team.
“The high magnetic stability combined with electrical reading and writing shows that single-atom magnetic memory is indeed possible,” the researchers conclude.
Watch the video. URL:https://youtu.be/2laKpYWIa5I
Scientists have built the world’s thinnest electric generator – and it’s only one atom wide
Researchers have created a graphene-like material that generates electricity every time its stretched, and could power the wearable technology of the future.
Scientists from the Georgia Institute of Technology and Columbia Engineering in the US have shown they can generate electricity from a layer of material that’s just one atom thick. The generator is made from molybdenum disulphide (MoS2), which is a clear, flexible and extremely light material that opens up huge possibilities for the future of electricity generation.
The new electrical generator is an example of piezoelectricity, or electricity that’s generated from pressure. Piezoelectric materials have huge potential to be used to create materials that can charge devices, such as footwear that powers an iPod. But until now, scientists have struggled to make these materials thin and flexible enough to be practical.
However, it’s been predicted that a substance capable of forming single-atom-thick molecules, or two-dimensional layers, would be highly piezoelectric.
Now the scientists have proved that this is the case for the first time ever. Their results have beenpublished in Nature.
To test whether MoS2 would be piezoelectric on the atomic scale, the team flaked off extremely thin layers of MoS2 onto a flexible substrate with electrical contact.
Because of the way these flakes were created, each had a slightly different number of layers – for example, while some were just one-atom-thick, others were eight-atoms-thick.
The scientists tested the piezoelectric response of these flakes by stretching the material, and measuring the flow of electrons into an external circuit.
Interestingly, they discovered that when the material had an odd number of layers, it generated electricity when stretched. But when it had an even number of layers, there was no current generated.
A single one-atom-thick layer of the material was able to generate 15 megavolts of electricity when stretched.
They also found that as the number of layers increased, the amount of current generated decreased, until eventually the material got too thick and stopped producing any electricity at all.
Computational studies suggest that this is because the atomic layers all have random orientations, and they eventually cancel each other out.
The research team also arranged these one-atom-thick layers of MoS2 into arrays, and found that together they were capable of generating a large amount of electricity.
This suggests that they’re a promising candidate for powering nano electronics, and could be used to create wearable technologies.
“This material – just a single layer of atoms – could be made as a wearable device, perhaps integrated into clothing, to convert energy from your body movement to electricity and power wearable sensors or medical devices, or perhaps supply enough energy to charge your cell phone in your pocket,” said James Hone, professor of mechanical engineering at Columbia engineering and co-leader of the research,
Crystal seen growing in slow motion one atom at a time.
Nano builders rejoice: for the first time, scientists have watched crystals grow atom by atom, offering incredible control over their microscopic structure. The technique could lead to customisable crystals that would find uses in diverse fields, from water purifiers to cloaking technologies.
“For the first time, we can actually image the motion of individual atoms, and observe the atom-by-atom assembly of crystals,” says Nicolas Barry at the University of Warwick, UK.
In the nanoscale world, rods, spheres and dots made from the same material have dramatically different chemical and physical properties. But until now, our control over such structures has been limited because they grow too fast for even the best electron microscopes to follow.
Barry and his colleagues fired a beam of electrons at a thin film of molecules containing the metal osmium, carbon and other elements. Most molecules broke down to release single osmium atoms, and the remaining film fused into a graphene lattice that supported the free atoms. Crucially, this graphene support contained impurities.
Mix and match
“It’s doped with boron and sulphur atoms, which slow down the motion of individual metal atoms on the graphene surface,” says Barry. The sluggish atoms move at the same rate as the image-capture speed of electron microscopes, allowing the team to see crystal growth in action.
The team also used a mix of metal atoms to produce an alloy of osmium and ruthenium for the first time, demonstrating that the technique could conceivably create other novel materials with interesting properties.
The method should make it possible to watch how crystals grow from different chemical recipes and figure out how to make customised crystals for use in diverse fields. It could also allow us to introduce desirable defects into crystals.
Sticky problem
“The ability to watch single atoms combine one by one to form nanoparticles is a significant contribution to understanding how materials form at the atomic level,” says Thomas Chamberlain at the University of Nottingham, UK.
But the reactivity of the crystal presents a hurdle, he says. Without a stabilising shell covering a particle’s surface, the material will continue to stick to any other particle it encounters, growing larger and becoming less active. “The useful properties of these crystals will change rapidly over time and then cease quite quickly.”
Still, having uncoated “islands” of highly reactive crystals on a graphene grid could be useful, says Barry. Such a set-up could detect gases or drugs at the atomic scale, for instance. “This combination could be extremely efficient for nano-catalytic applications – but we don’t know yet,” he says.
Journal reference: Nature Communications
What can a graphene sandwich reveal about proteins?
Stronger than steel, but only one atom thick – latest research using the 2D miracle material graphene could be the key to unlocking the mysteries around the structure and behaviour of proteins in the very near future.
Scientists at The University of Manchester and the SuperSTEM facility, which is located at STFC’s Daresbury Laboratory and funded by the Engineering and Physical Sciences Research Council (EPSRC), have discovered that the most fragile, microscopic materials can be protected from the harmful effects of radiation when under the microscope if they are ‘sandwiched’ between two sheets of graphene. The technique could soon be the key to enabling the direct study of every single individual atom in a protein chain, something yet to be achieved, and revolutionise our understanding of cell structure, how the immune system reacts to viruses and aid in the design of new antiviral drugs.
Observing the structure of some the tiniest of objects, such as proteins and other sensitive 2D materials, at the atomic scale requires a powerful electron microscope. This is exceptionally difficult because the radiation from the electron beam can destroy the highly fragile object being imaged before any useful data can be accurately recorded. However, by protecting fragile objects between two sheets of graphene it means they can be imaged for longer without damage under the electron beam, making it possible to quantitatively identify every single atom within the structure. This technique has proven very successful on the test case of a fragile in-organic 2D crystal and the results published in the journal ACS Nano.
During this research, the team of scientists, which included Sir Kostya Novoselov, who shared a Nobel Prize in Physics in 2010 for exploiting the remarkable properties of graphene, were able to observe the effects of encapsulating a microscopic crystal of another highly fragile 2D material, molybdenum di-sulfide, between two sheets of graphene. They found that they were able to apply a high electron beam to directly image, identify and obtain complete chemical analysis of each and every atom within the molybdenum di-sulfide sheet, without causing any defects to the material through radiation.
The University of Manchester’s Dr Recep Zan, who led the research team, said: “Graphene is a million times thinner than paper, yet stronger than steel, with fantastic potential in areas from electronics to energy. But this research shows its potential in biochemistry could also be just as significant, and could eventually open up all sorts of applications in the biotechnology arena.”
Professor Quentin Ramasse, Scientific Director at SuperSTEM added: “What this research demonstrates is not so much about graphene itself, but how it can impact the detail and accuracy at which we can directly study other inorganic 2D materials or highly fragile molecules. Until now this has mostly been possible through less direct and often complicated methods such as protein crystallography which do not provide a direct visualisation of the object in question. This new capability is particularly exciting because it could pave the way to being able to image every single atom in a protein chain for example, something which could significantly impact our development of treatments for conditions such as cancer, Alzheimer’s and HIV.”
Atomic bonds between their atoms .
A pioneering team from IBM in Zurich has published single-molecule images so detailed that the type of atomic bonds between their atoms can be discerned.
The same team took the first-ever single-molecule image in 2009 and more recently published images of a molecule shaped like the Olympic rings.
The new work opens up the prospect of studying imperfections in the “wonder material” graphene or plotting where electrons go during chemical reactions.
The team, which included French and Spanish collaborators, used a variant of a technique called atomic force microscopy, or AFM.
AFM uses a tiny metal tip passed over a surface, whose even tinier deflections are measured as the tip is scanned to and fro over a sample.
The IBM team’s innovation to create the first single molecule picture, of a molecule called pentacene, was to use the tip to pick up a single, small molecule made up of a carbon and an oxygen atom.
This carbon monoxide molecule effectively acts as a record needle, probing with unprecedented accuracy the very surfaces of atoms.
It is difficult to overstate what precision measurements these are.
The experiments must be isolated from any kind of vibration coming from within the laboratory or even its surroundings.
They are carried out at a scale so small that room temperature induces wigglings of the AFM’s constituent molecules that would blur the images, so the apparatus is kept at a cool -268C.
While some improvements have been made since that first image of pentacene, lead author of the Science study, Leo Gross, told BBC News that the new work was mostly down to a choice of subject.
The new study examined fullerenes – such as the famous football-shaped “buckyball” – and polyaromatic hydrocarbons, which have linked rings of carbon atoms at their cores.
The images show just how long the atomic bonds are, and the bright and dark spots correspond to higher and lower densities of electrons.
Together, this information reveals just what kind of bonds they are – how many electrons pairs of atoms share – and what is going on chemically within the molecules.
“In the case of pentacene, we saw the bonds but we couldn’t really differentiate them or see different properties of different bonds,” Dr Gross said.
“Now we can really prove that… we can see different physical properties of different bonds, and that’s really exciting.”
The team will use the method to examine graphene, one-atom-thick sheets of pure carbon that hold much promise in electronics.
But defects in graphene – where the perfect sheets of carbon are buckled or include other atoms – are currently poorly understood.
The team will also explore the use of different molecules for their “record needle”, with the hope of yielding even more insight into the molecular world.
Source: BBC
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