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ScienceDaily

Active material created out of microscopic spinning particles

At the atomic level, a glass of water and a spoonful of crystalline salt couldn’t look more different. Water atoms move around freely and randomly, while salt crystals are locked in place in a lattice. But some new materials, recently investigated by researchers at the U.S. Department of Energy’s (DOE) Argonne National Laboratory, show an intriguing propensity to sometimes behave like water and sometimes like salt, giving them interesting transport properties and holding potential promise for applications like mixing and delivery in the pharmaceutical industry.

These so-called active materials contain small magnetic particles that self-organize into short chains of particles, or spinners, and form a lattice-like structure when a magnetic field is applied. “Active materials need an external energy source to maintain their structure,” said Argonne materials scientist Alexey Snezhko, an author of the study.

Unlike in previous experiments involving active materials, which looked at particles that demonstrated linear motion, these new spinners acquire a handedness — like right- or left-handedness — that causes them to rotate in a specific direction.

This twirling rotation of the suspended self-assembled nickel spinners creates a whirlpool-like effect, in which different particles can get sucked in to the vortices created by their neighbors. “The particles don’t move on their own, but they can be dragged around,” Snezhko said. “The interesting thing is that you can have these very quickly rotating structures that give the appearance of a yet larger system that is still, but it remains quite active.”

As the particles start to come together, the whirlpools created by the spinning motion — in conjunction with the magnetic interactions — pull them even closer, creating a fixed crystalline-like material, even as the spinners still rotate.

The Argonne researchers wanted to know how a non-spinner particle would be transported through the active lattice. According to Snezhko, the rapid whirling of the spinners creates the ability for these other cargo particles to move through the lattice much more quickly than they would through a normal material. “In regular diffusion, the process of getting a particle from one side of the material to the other is temperature-dependent and takes a much longer period of time,” he said.

The transport of a non-spinner particle is also dependent upon the spacing between the spinners. If the spinners are located sufficiently far apart, the non-spinner particle will travel chaotically between different spinners, like a raft traveling down a series of whitewater rapids. If the particles in the lattice come closer together, the non-spinner particle can become trapped in an individual cell of the lattice.

“Once the particle comes within a cell through its own chaotic motion, we can modify the field so that the lattice slightly shrinks, making the probability of the particle to leave that location in the lattice very low,” Snezhko said.

The material also showed the ability to undergo self-repair, similar to a biological tissue. When the researchers made a hole in the lattice, the lattice reformed.

By looking at systems with purely rotational motion, Snezhko and his colleagues believe that they can design systems with specific transport characteristics. “There are many different ways for getting an object in a material from point A to point B, and this type of self-assembly could be tailored for different dynamics,” he said.

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Materials provided by DOE/Argonne National Laboratory. Original written by Jared Sagoff. Note: Content may be edited for style and length.

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3D Printing Industry

Researchers develop low-cost 3D printed polarimeter for classroom use

Science and technology classes, particularly at University level, often require specialist apparatus that can be costly and difficult for students to get to grips with. This is where 3D printing can be of assistance, offering a low-cost method of manufacturing components for technical learning tools. Paweł Bernard from Jagiellonian University and James Mendez from Indiana […]

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Author: Kubi Sertoglu

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ScienceDaily

Carbon chains adopt fusilli or spaghetti shapes if they have odd or even numbers

Helical shapes are very familiar in the natural world and, at the molecular level, of DNA, the very blueprint of life itself.

Scientists at the University of Bristol have now found that carbon chains can also adopt helical shapes, but, unlike DNA, the shape is dependent on how many atoms there are in the chain, with chains having even numbers of carbon atoms adopting helical, fusilli-like shapes and chains with odd numbers of carbon atoms adopting floppy, spaghetti-like shapes.

The difference, say the research team, between order and chaos is a single carbon atom. Their study is published today in the journal Nature Chemistry.

Carbon chains are like spaghetti — they are rather floppy and adopt a set of random and constantly changing shapes.

The Bristol team, from the University’s School of Chemistry, showed that by judicious insertion of methyl substituents along carbon chains they could control their shape so that they adopted well-defined linear (penne) or helical (fusilli) conformations.

The helical conformations can adopt either right or left-handed helices and the team were interested to know what controlled which helix was formed.

Lead author, Professor Varinder Aggarwal, said: “We were astonished to find that the length of the carbon chain (number of carbon atoms) controlled whether the right or left-handed helix formed.

“Even more surprising was that carbon chains with even numbers of atoms formed well-defined helical structures (fusilli) but odd numbered carbon chains were much floppier and more random in shape (spaghetti).

“The change in properties of a homologous series of molecules caused by the single addition of an extra carbon atom is extremely rare — here it results in the difference between order and chaos.”

This type of odd-even effect has been observed in some bulk properties, such as in carpets of alkanethiols on a gold surface, but such behaviours in solution are not well recognised or understood.

Through computation and measurement of molecular properties, Professor Aggarwal and his team have been able to fully understand the origin of this odd-even effect which is controlled by the end groups.

When the end groups both promote the same sense of helicity, an ordered structure is obtained, but when each end promotes an opposite helix, chaotic structures are obtained.

For future technological applications, these fundamental findings will guide the design of molecules with desirable conformational, and physical properties.

Carbon chains with an even number of atoms will lead to molecules with well-defined helical shapes for their application as non-switchable rigid materials or as scaffolds for the presentation of molecular recognition elements.

Helices are a fundamental structure in biological molecules (DNA, proteins) and it is intriguing to imagine the analogies to molecules of the sort described in the study.

Professor Aggarwal added: “Carbon chains with an odd number of atoms were found to adopt floppier and more random shape.

“We are now studying whether the shape of these chains can in fact be controlled by manipulating the groups at the ends of the chain. This may enable us to switch from one screw-sense to another for applications in responsive materials.”

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Materials provided by University of Bristol. Note: Content may be edited for style and length.

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ScienceDaily

The mysterious movement of water molecules

Water is a mysterious substance. Understanding how it behaves at the atomic level is still a challenge for experimental physicists, as light hydrogen and oxygen atoms are difficult to observe using conventional experimental methods. This is especially true for any researcher looking to study the microscopic movements of individual water molecules that run off a surface in a matter of picoseconds. As they report in their paper, entitled ‘Nanoscopic diffusion of water on a topological insulator’, researchers from the Exotic Surfaces working group at TU Graz’s Institute of Experimental Physics joined forces with counterparts from the Cavendish Laboratory at the University of Cambridge , the University of Surrey and Aarhus University. Together, they made significant advances, performing research into the behaviour of water on a material that is currently attracting particular interest: a topological insulator called bismuth telluride. This compound could be used to build quantum computers. Water vapour would be one of the environmental factors to which applications based on bismuth telluride might be exposed during operation.

In the course of their research, the team used a combination of a new experimental method called helium spin-echo spectroscopy and theoretical calculations. Helium spin-echo spectroscopy uses very low-energy helium atoms that allow isolated water molecules to be observed without influencing their motion in the process. The researchers discovered that water molecules behave completely differently on bismuth telluride compared with those on conventional metals. On such metals, attractive interactions between water molecules can be observed, leading to accumulations in the form of films. But the opposite is the case with topological insulators: the water molecules repel one another and remain isolated on the surface.

Bismuth telluride appears to be impervious to water, which is an advantage for applications exposed to typical environmental conditions. Plans are in place for further experiments on similarly structured surfaces, which are intended to clarify whether the movement of water molecules is attributable to specific features of the surface in question.

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Materials provided by Graz University of Technology. Original written by Birgit Baustädter. Note: Content may be edited for style and length.


Journal Reference:

  1. Anton Tamtögl, Marco Sacchi, Nadav Avidor, Irene Calvo-Almazán, Peter S. M. Townsend, Martin Bremholm, Philip Hofmann, John Ellis, William Allison. Nanoscopic diffusion of water on a topological insulator. Nature Communications, 2020; 11 (1) DOI: 10.1038/s41467-019-14064-7

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Graz University of Technology. “The mysterious movement of water molecules.” ScienceDaily. ScienceDaily, 15 January 2020. <www.sciencedaily.com/releases/2020/01/200115120607.htm>.

Graz University of Technology. (2020, January 15). The mysterious movement of water molecules. ScienceDaily. Retrieved January 15, 2020 from www.sciencedaily.com/releases/2020/01/200115120607.htm

Graz University of Technology. “The mysterious movement of water molecules.” ScienceDaily. www.sciencedaily.com/releases/2020/01/200115120607.htm (accessed January 15, 2020).

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ScienceDaily

Artificial skin creates first ticklish devices

A new interface developed by researchers in Bristol and Paris takes touch technology to the next level, by providing an artificial skin-like membrane for augmenting interactive devices such as phones, wearables or computers.

The Skin-On interface, developed by researchers at the University of Bristol in partnership with Telecomm ParisTech and Sorbonne University, mimics human skin in appearance but also in sensing resolution.

The researchers adopted a bio-driven approach to developing a multi-layer, silicone membrane that mimics the layers present in human skin. This is made up of a surface textured layer, an electrode layer of conductive threads and a hypodermis layer. Not only is the interface more natural than a rigid casing, it can also detect a plethora of gestures made by the end-users. As a result, the artificial skin allows devices to ‘feel’ the user’s grasp — its pressure and location, and can detect interactions such as tickling, caressing, even twisting and pinching.

“This is the first time we have the opportunity to add skin to our interactive devices. The idea is perhaps a bit surprising, but skin is an interface we are highly familiar with so why not use it and its richness with the devices we use every day?” said Dr Anne Roudaut, Associate Professor in Human-Computer Interaction at the University of Bristol, who supervised the research.

“Artificial skin has been widely studied in the field of Robotics but with a focus on safety, sensing or cosmetic aims. This is the first research we are aware of that looks at exploiting realistic artificial skin as a new input method for augmenting devices,” said Marc Teyssier, lead author.

In the study, researchers created a phone case, computer touch pad and smart watch to demonstrate how touch gestures on the Skin-On interface can convey expressive messages for computer mediated communication with humans or virtual characters.

“One of the main use of smartphones is mediated communication, using text, voice, video, or a combination. We implemented a messaging application where users can express rich tactile emotions on the artificial skin. The intensity of the touch controls the size of the emojis. A strong grip conveys anger while tickling the skin displays a laughing emoji and tapping creates a surprised emoji” said Marc Teyssier.

“This work explores the intersection between man and machine. We have seen many works trying to augment human with parts of machines, here we look at the other way around and try to make the devices we use every day more like us, i.e. human-like,” said Dr Roudaut.

It may not be long before these tactile devices become the norm. The paper offers all the steps needed to replicate this research, and the authors are inviting developers with an interest in Skin-On interfaces to get in touch.

Researchers say the next step will be making the skin even more realistic. They have already started looking at embedding hair and temperature features which could be enough to give devices — and those around them — goose-bumps.

Paper: Marc Teyssier, Gilles Bailly, Catherine Pelachaud, Eric Lecolinet, Andrew Conn, Anne Roudaut. Skin-On Interfaces: A Bio-Driven Approach for Artificial Skin Design to Cover Interactive Devices. UIST 2019

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Materials provided by University of Bristol. Note: Content may be edited for style and length.

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Hackster.io

DIY Responsive LED Panel Will Turn Any Surface Into an Interactive Light Display

Active or responsive LED panels can add a new aesthetic level to floors, desks, walls, or any flat surface, but they can be costly — Nanoleaf, Sensacell, and BrightLogic are prime examples. Sometimes it’s best to go the DIY route, which is what electronic enthusiast Rodney Trusty did with his responsive LED panel, which can be programmed to light up when an object gets near its sensors.

Trusty used a series of panels to create an interactive table, which he states, “The table works on infrared light, so no touch or pressure is required. I’ve also made custom PCBs to drastically reduce build time. My first build took 40+ hours. With the custom PCB it can be done in 1 hour give or take.” He designed his responsive LED panel using 16 WS2812 (5050) addressable LEDs, 16 IR LEDs, 16 IR photoresistors, a custom PCB, and an Arduino Uno to control the show.

Trusty developed his custom PCB with component placement diagrams stenciled on the board, making it simple to locate and solder the electronics in their correct areas. There’s also an area where you can solder a pinout for connecting the Arduino. He also made it easy to install the necessary code to get the responsive panel up and running by adding comments that are easy to understand, although you can upload and go if needed.

You can find a great walkthrough of Trusty’s responsive LED panel on his project page if you would like to recreate his build. He’s even offering his panel on Tindie for $15 in kit form, $30 with the SMD components pre-soldered, and $45 with all the parts pre-soldered.

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Author: Cabe Atwell

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Hackster.io

DEFCON 27: PCB Badge Art

All the badges!!! OK, DEFCON Hacking Conference was amazing, and the badge makers took it to a whole new level. See what we mean in this rundown of the coolest badges we found!
Did we miss one? Which were your faves? Let us know in the comments!

// https://seckc.org/
// https://badgepirates.com/
// https://twitter.com/s7a73farm
// https://twitter.com/LithoChasm
// https://twitter.com/hamster
// https://twitter.com/cromulonb
// https://twitter.com/kalamityjaine
// https://twitter.com/oshpark/status/1161500063337779202
// https://www.youtube.com/channel/UCO8DQrSp5yEP937qNqTooOw
// https://hackaday.io/project/164625-dc27-multi-pass
// https://mkfactor.com/?p=67

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ScienceDaily

Atomic ‘Trojan horse’ could inspire new generation of X-ray lasers and particle colliders

How do researchers explore nature on its most fundamental level? They build “supermicroscopes” that can resolve atomic and subatomic details. This won’t work with visible light, but they can probe the tiniest dimensions of matter with beams of electrons, either by using them directly in particle colliders or by converting their energy into bright X-rays in X-ray lasers. At the heart of such scientific discovery machines are particle accelerators that first generate electrons at a source and then boost their energy in a series of accelerator cavities.

Now, an international team of researchers, including scientists from the Department of Energy’s SLAC National Accelerator Laboratory, has demonstrated a potentially much brighter electron source based on plasma that could be used in more compact, more powerful particle accelerators.

The method, in which the electrons for the beam are released from neutral atoms inside the plasma, is referred to as the Trojan horse technique because it’s reminiscent of the way the ancient Greeks are said to have invaded the city of Troy by hiding their forceful soldiers (electrons) inside a wooden horse (plasma), which was then pulled into the city (accelerator).

“Our experiment shows for the first time that the Trojan horse method actually works,” says Bernhard Hidding from the University of Strathclyde in Glasgow, Scotland, the principal investigator of a study published today in Nature Physics. “It’s one of the most promising methods for future electron sources and could push the boundaries of today’s technology.”

Replacing metal with plasma

In current state-of-the-art accelerators, electrons are generated by shining laser light onto a metallic photocathode, which kicks electrons out of the metal. These electrons are then accelerated inside metal cavities, where they draw more and more energy from a radiofrequency field, resulting in a high-energy electron beam. In X-ray lasers, such as SLAC’s Linac Coherent Light Source (LCLS), the beam drives the production of extremely bright X-ray light.

But metal cavities can only support a limited energy gain over a given distance, or acceleration gradient, before breaking down, and therefore accelerators for high-energy beams become very large and expensive. In recent years, scientists at SLAC and elsewhere have looked into ways to make accelerators more compact. They demonstrated, for example, that they can replace metal cavities with plasma that allows much higher acceleration gradients, potentially shrinking the length of future accelerators 100 to 1,000 times.

The new paper expands the plasma concept to the electron source of an accelerator.

“We’ve previously shown that plasma acceleration can be extremely powerful and efficient, but we haven’t been able yet to produce beams with high enough quality for future applications,” says co-author Mark Hogan from SLAC. “Improving beam quality is a top priority for the next years, and developing new types of electron sources is an important part of that.”

According to previous calculations by Hidding and colleagues, the Trojan horse technique could make electron beams 100 to 10,000 times brighter than today’s most powerful beams. Brighter electron beams would also make future X-ray lasers brighter and further enhance their scientific capabilities.

“If we’re able to marry the two major thrusts — high acceleration gradients in plasma and beam creation in plasma — we could be able to build X-ray lasers that unfold the same power over a distance of a few meters rather than kilometers,” says co-author James Rosenzweig, the principal investigator for the Trojan horse project at the University of California, Los Angeles.

Producing superior electron beams

The researchers carried out their experiment at SLAC’s Facility for Advanced Accelerator Experimental Tests (FACET). The facility, which is currently undergoing a major upgrade, generates pulses of highly energetic electrons for research on next-generation accelerator technologies, including plasma acceleration.

First, the team flashed laser light into a mixture of hydrogen and helium gas. The light had just enough energy to strip electrons off hydrogen, turning neutral hydrogen into plasma. It wasn’t energetic enough to do the same with helium, though, whose electrons are more tightly bound than those for hydrogen, so it stayed neutral inside the plasma.

Then, the scientists sent one of FACET’s electron bunches through the plasma, where it produced a plasma wake, much like a motorboat creates a wake when it glides through the water. Trailing electrons can “surf” the wake and gain tremendous amounts of energy.

In this study, the trailing electrons came from within the plasma (see animation above and movie below). Just when the electron bunch and its wake passed by, the researchers zapped the helium in the plasma with a second, tightly focused laser flash. This time the light pulse had enough energy to kick electrons out of the helium atoms, and the electrons were then accelerated in the wake.

The synchronization between the electron bunch, rushing through the plasma with nearly the speed of light, and the laser flash, lasting merely a few millionths of a billionth of a second, was particularly important and challenging, says UCLA’s Aihua Deng, one of the study’s lead authors: “If the flash comes too early, the electrons it produces will disturb the formation of the plasma wake. If it comes too late, the plasma wake has moved on and the electrons won’t get accelerated.”

The researchers estimate that the brightness of the electron beam obtained with the Trojan horse method can already compete with the brightness of existing state-of-the-art electron sources.

“What makes our technique transformative is the way the electrons are produced,” says Oliver Karger, the other lead author, who was at the University of Hamburg, Germany, at the time of the study. When the electrons are stripped off the helium, they get rapidly accelerated in the forward direction, which keeps the beam narrowly bundled and is a prerequisite for brighter beams.

More R&D work ahead

But before applications like compact X-ray lasers could become a reality, much more research needs to be done.

Next, the researchers want to improve the quality and stability of their beam and work on better diagnostics that will allow them to measure the actual beam brightness, instead of estimating it.

These developments will be done once the FACET upgrade, FACET-II, is completed. “The experiment relies on the ability to use a strong electron beam to produce the plasma wake,” says Vitaly Yakimenko, director of SLAC’s FACET Division. “FACET-II will be the only place in the world that will produce such beams with high enough intensity and energy.”

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Thingiverse

Geometric Concrete Pot Mold

Step up your 3d Printed projects to a new level !!

With 3 parts of PLA you can create this amazing geometric planter or pot for many uses. Just Print 2 sides and the internal piece (VASE MODE with flexible PLA is better) and assemble it. Once you have it, mix some concrete and trow it into the mold.

You can print it in the size you want !! Combine scales: 1 + 0,8 + 0,6 and you will have the 3 beautiful combo of the first picture.

The molds lasts at least 5 times – With a slow print and a good wash of the mold it can last up to 20 casts.

Experiment with concrete ! Add some color to the mix ! Marble them ! Cast with other materials like resin ! Or just paint it !

ICE CREAM TOO !!
https://www.thingiverse.com/thing:3396483

To achieve a perfect finish use a Concrete Sealer of your choice.(Acrylic or solvent based) Just wipe the concrete surface and let it dry. With each layer of sealer, the concrete becomes less penetrable for liquids and creates a smoother finish.

If u dont want to do all of this in concrete… here is the LAZY VERSION !!

https://www.thingiverse.com/thing:3743407

Take the finished planter right out of your 3d printer 😉

Dont forget to post your make on Instagram !
@esparapse // @by.bang

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