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SteveMDFP

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Material Science
« on: February 04, 2022, 12:32:06 PM »
Polyaramide, a first-ever 2-dimensional polymer.  It has a not very catchy name right now, 2DPA-1.

MIT Engineers Create the “Impossible” – New Material That Is Stronger Than Steel and As Light as Plastic
https://scitechdaily.com/mit-engineers-create-the-impossible-new-material-that-is-stronger-than-steel-and-as-light-as-plastic/

"Polymer scientists have long hypothesized that if polymers could be induced to grow into a two-dimensional sheet, they should form extremely strong, lightweight materials. However, many decades of work in this field led to the conclusion that it was impossible to create such sheets. One reason for this was that if just one monomer rotates up or down, out of the plane of the growing sheet, the material will begin expanding in three dimensions and the sheet-like structure will be lost.

However, in the new study, Strano and his colleagues came up with a new polymerization process that allows them to generate a two-dimensional sheet called a polyaramide. For the monomer building blocks, they use a compound called melamine, which contains a ring of carbon and nitrogen atoms. Under the right conditions, these monomers can grow in two dimensions, forming disks. These disks stack on top of each other, held together by hydrogen bonds between the layers, which make the structure very stable and strong....

The researchers found that the new material’s elastic modulus — a measure of how much force it takes to deform a material — is between four and six times greater than that of bulletproof glass. They also found that its yield strength, or how much force it takes to break the material, is twice that of steel, even though the material has only about one-sixth the density of steel."
_____________________________________________________________

This topic may *seem* far removed from cryosphere and climate, but this material appears to be incredibly useful for a huge range of situations.  Many varied materials currently in use can shortly be made from an incredibly strong, durable, colorless material.  This appears to be a material that could be a superior replacement for many applications of steel, glass, concrete, carbon fiber, and many more.

Hulls of boats, spacecraft, car bodies, body armor, rebar coating, cell phone display coatings, roadways, buildings, films for triple-glazed windows.  The Boeing 787 has a body made of carbon fiber--this could be superior.  Spacecraft bodies (though probably not for surfaces of reentry vehicles).  It's highly impermeable to gases, so interior coatings of pipelines.  Or just make the pipelines from this material.  Depending on physical properties of thin film, perhaps use it for helium balloon applications.

Yes, it's a plastic.  And in general, we want to reduce plastic use.  But regular plastic isn't durable or long-lasting.  This stuff seems to be durable, strong, and long-lasting.  I'm sure the monomer, melamine, is a petrochemical.  But unlike other materials, production shouldn't emit a lot of CO2, nor use a large amount of energy.  It may be environmentally friendlier to use this material in place of many other materials.  It could eliminate the pesky emissions from cement production.

And for anything that has to move (e.g., vehicles), reducing weight will reduce energy consumption.

kassy

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Re: Material Science
« Reply #1 on: February 04, 2022, 02:12:17 PM »
Melamine can be manufactured from dicyandiamide, hydrogen cyanide, or urea. Modern commercial production of melamine typically employs urea as a starting material. Urea is broken down to cyanuric acid, which then can be reacted to form melamine. Its most important reaction is that with formaldehyde, forming melamine-formaldehyde resins of high molecular weight.

https://www.britannica.com/science/melamine

Technically a plastic but you can help making it.

In the article they mainly talk about coating but that already has it´s uses. 
Þetta minnismerki er til vitnis um að við vitum hvað er að gerast og hvað þarf að gera. Aðeins þú veist hvort við gerðum eitthvað.

Bruce Steele

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Re: Material Science
« Reply #2 on: February 05, 2022, 03:34:42 PM »
My first thought was polyaramide might make a good replacement for polycarbonate greenhouse sheeting.

vox_mundi

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Re: Material Science
« Reply #3 on: February 05, 2022, 03:51:07 PM »
They're opaque to semi transparent and sensitive to UV radiation.
“There are three classes of people: those who see. Those who see when they are shown. Those who do not see.” ― anonymous

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Bruce Steele

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Re: Material Science
« Reply #4 on: February 05, 2022, 06:00:10 PM »
I read “film for triple paned windows” and got ahead of myself.

morganism

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Re: Material Science
« Reply #5 on: May 18, 2022, 12:01:22 AM »
The World’s Most Powerful X-Ray Is Now Colder Than Space

Nestled underground beneath Stanford University is the Linac Coherent Light Source (LCLS), a powerful X-ray laser managed by the SLAC National Accelerator Laboratory. Since 2009, the particle accelerator has given scientists an unprecedented look at the molecular and atomic structure of matter by shooting electrons through a copper pipe and generating 120 X-ray pulses per second. It’s often considered the world’s most powerful X-ray as a result—and it’s about to get even more powerful.


SLAC is in the final stages of the LCLS-II upgrade project. Once finished, the accelerator will be able to generate a million X-ray pulses per second. To do so, though, the machine needs to be capable of superconducting—a term that describes the disappearance of electrical resistance—allowing the electrons to move even faster. The only way to achieve this is by making things very, very cold. That’s why the team installed a series of supercooling modules to a half-mile stretch of the accelerator, successfully bringing temperatures down to nearly absolute zero on April 15.

“In just a few hours, LCLS-II will produce more X-ray pulses than the current laser has generated in its entire lifetime,” Mike Dunne, director of LCLS, said in a press release. “Data that once might have taken months to collect could be produced in minutes. It will take X-ray science to the next level, paving the way for a whole new range of studies and advancing our ability to develop revolutionary technologies to address some of the most profound challenges facing our society.”

https://www.thedailybeast.com/the-worlds-most-powerful-x-ray-at-stanford-university-is-now-colder-than-space?source=articles&via=rss

morganism

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Re: Material Science
« Reply #6 on: September 10, 2023, 07:20:48 PM »
How to Make a Synthetic Diamond

(Graphite, oil , and a microwave)

https://www.instructables.com/How-to-Make-a-Synthetic-Diamond/

morganism

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Re: Material Science
« Reply #7 on: September 22, 2023, 11:11:08 PM »
Andrew Côté  @Anderco Sep 15       (the next frontier for AI/ML)

Materials Science is about to be revolutionized by Self Driving Robotic Laboratories.

Optimizing atoms is the hardest of hard-tech problems and defines whats possible for every other engineering discipline.

A 🧵 on how SDL will speed-run science to unlock a new Golden Age

https://nitter.poast.org/Andercot/status/1702580298213392487#m


When humanity learns the recipe for a new material, the world changes. Bronze gave us the breast-plate, steel gave us the railroads, and semiconductors the world today.

We've optimized solar cells to give unimaginably high efficiencies over 50 years of hard-fought battles

Materials science is hard because the number of possible recipes is vast, and we don't have complete theories to guide where to look.

Trying out a recipe and measuring the material that results is laborious, repetitive, and multidisciplinary.

SDL's can operate 1000x faster

General purpose robotics and specially designed laboratory environments enable automation of the material synthesis and testing processes entirely.

To optimize a photocatalyst engineers made an SDL perform 688 experiments over 8 days, varying 10 continuous input parameters.

The space of possible recipes rapidly explodes in the number of variables and fine-ness of your knobs for tuning them, easily into the tens of millions.

Methods like Bayesian learning optimize the frontier of explored recipes - the Pareto Front.

Self-Driving Labs have already been proven out with multiple different workflows to speed-run materials science.

But scientific discovery isn't just about grinding out experiments. We need intuition, theory, and new hypotheses.

We need machines with physics world-models.

The synthesis of ML/AI methods with simulation software used to understand physical properties creates a new class of 'self-driving lab' - the robotic theorist.

Imbuing artificial minds with true quantum mechanical that speak the language of atoms fluently.

Physics-modeling software has already revolutionized chemistry and biology, with companies like Schrodinger reaching unicorn status by modeling  interactions at the molecular scale

But, solving the electrostatics of molecules is far easier than the quantum mechanics of atoms

Without a quantum computer, simulating QM problems means using tools like Density Functional Theory to approximately solve the many-body Schrodinger equation at great CPU expense.

Companies like @QuantumGenMat are combining DFT with ML/AI to achieve 10-100x faster results

Engineers dreamed of the transistor to make automated switchboards and smaller radios.

Today we have machines that think.

Quantum-engineered materials can place humanity on the next economic growth curve to last a hundred years, and change every feature of our built world

Materials live in deca-million parameter recipe spaces. Machines can develop intuition for phenomena that exist in deca-million to billion parameter spaces.

Machine-scientists directing massively parallel automated labs, refining their knowledge hundreds of times a day.

In the last few years self-driving laboratories have reached version 1.0 status at several research universities.

The potential commercial impact of the discoveries that await are measured in the tens of trillions.

In the future, agentic machine scientists with internal world-models of fundamental physics will be at the heart of the robot lab.

Speed-running the space of possible experiments, coaxing recipes from nature that forever redefine whats possible.

Accelerating the frontiers of material science will be one of the greatest positive-sum investments of time, energy, and capital in history.

If you know people working in this field, please tag them.

If you know of companies in SDL please reach out.

Follow @andercot for more

morganism

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Re: Material Science
« Reply #8 on: September 23, 2023, 09:34:32 PM »
(tech similar to study prev posted on deformations making materials less susceptible to cat failure. This clever technique reminds me of silver polymer clay used in jewelery making)

Technique for 3D printing metals at the nanoscale reveals surprise benefit

by Emily Velasco, California Institute of Technology

A nanoscale lattice prepared using a new technique developed by the lab of Julia R. Greer. Credit: Caltech

Late last year, Caltech researchers revealed that they had developed a new fabrication technique for printing microsized metal parts containing features about as thick as three or four sheets of paper.

Now, the team has reinvented the technique to allow for printing objects a thousand times smaller: 150 nanometers, which is comparable to the size of a flu virus. In doing so, the team also discovered that the atomic arrangements within these objects are disordered, which would, at large scale, make these materials unusable because they would be considered weak and "low quality." In the case of nanosized metal objects, however, this atomic-level mess has the opposite effect: these parts can be three-to-five-times stronger than similarly sized structures with more orderly atomic arrangements.

The work was conducted in the lab of Julia R. Greer, the Ruben F. and Donna Mettler Professor of Materials Science, Mechanics and Medical Engineering; and Fletcher Jones Foundation Director of the Kavli Nanoscience Institute. The paper describing the work, "Suppressed Size Effect in Nanopillars with Hierarchical Microstructures Enabled by Nanoscale Additive Manufacturing," is published in the August issue of Nano Letters.

The new technique is similar to another announced by the team last year, but with each step of the process reimagined to work at the nanoscale. However, this presents an additional challenge: the manufactured objects are not visible to the naked eye or easily manipulatable.

The process starts with preparing a photosensitive "cocktail" that is largely comprised of a hydrogel, a kind of polymer that can absorb many times its own weight in water. This cocktail is then selectively hardened with a laser to build a 3D scaffold in the same shape as the desired metal objects. In this research, those objects were a series of tiny pillars and nanolattices.

The hydrogel parts are then infused with an aqueous solution containing nickel ions. Once the parts are saturated with metal ions, they are baked until all the hydrogel is burned out, leaving parts in the same shape as the original, though shrunken, and consisting entirely of metal ions that are now oxidized (bound to oxygen atoms). In the final step, the oxygen atoms are chemically stripped out of the parts, converting the metal oxide back into a metallic form.

In the last step, the parts develop their unexpected strength.
The irregular interior structure of a nanoscale nickel pillar. Credit: Caltech

"There are all these thermal and kinetic processes occurring simultaneously during this process, and they lead to a very, very messy microstructure," she says. "You see defects like pores and irregularities in the atomic structure, which are typically considered to be strength-deteriorating defects. If you were to build something out of steel, say, an engine block, you would not want to see this type of microstructure because it would significantly weaken the material."

However, Greer says they found exactly the opposite. The many defects that would weaken a metal part at a larger scale strengthen the nanoscale parts instead.

When a pillar is defect free, failure occurs catastrophically along what is known as a grain boundary—the place where the microscopic crystals that make up material butt up against each other.

But when the material is full of defects, a failure cannot easily propagate from one grain boundary to the next. That means the material won't suddenly fail because the deformation becomes distributed more evenly throughout the material.

"Usually, the deformation carrier in metal nanopillars—that is, a dislocation or slip—propagates until it can escape at the outer surface," says Wenxin Zhang, lead author of the work and a graduate student in mechanical engineering. "But in the presence of interior pores, the propagation will quickly terminate at the surface of a pore instead of continuing all the way through the entire pillar. As a rule of thumb, it's harder to nucleate a deformation carrier than to let it propagate, explaining why the present pillars may be stronger than their counterparts."

Greer believes that this is one of the first demonstrations of 3D printing of metal structures at the nanoscale. She notes that the process could be used for creating many useful components, such as catalysts for hydrogen; storage electrodes for carbon-free ammonia and other chemicals; and essential parts of devices such as sensors, microrobots, and heat exchangers.

"We were originally worried," she says. "We thought , 'Oh my, this microstructure is never going to lead to anything good,' but apparently, we did not have a reason to worry because it turns out it's not even a detriment. It's actually a feature."

https://phys.org/news/2023-09-technique-3d-metals-nanoscale-reveals.html


Suppressed Size Effect in Nanopillars with Hierarchical Microstructures Enabled by Nanoscale Additive Manufacturing

https://pubs.acs.org/doi/10.1021/acs.nanolett.3c02309


Studies on mechanical size effects in nanosized metals unanimously highlight both intrinsic microstructures and extrinsic dimensions for understanding size-dependent properties, commonly focusing on strengths of uniform microstructures, e.g., single-crystalline/nanocrystalline and nanoporous, as a function of pillar diameters, D. We developed a hydrogel infusion-based additive manufacturing (AM) technique using two-photon lithography to produce metals in prescribed 3D-shapes with ∼100 nm feature resolution. We demonstrate hierarchical microstructures of as-AM-fabricated Ni nanopillars (D ∼ 130–330 nm) to be nanoporous and nanocrystalline, with d ∼ 30–50 nm nanograins subtending each ligament in bamboo-like arrangements and pores with critical dimensions comparable to d. In situ nanocompression experiments unveil their yield strengths, σ, to be ∼1–3 GPa, above single-crystalline/nanocrystalline counterparts in the D range, a weak size dependence, σ ∝ D–0.2, and localized-to-homogenized transition in deformation modes mediated by nanoporosity, uncovered by molecular dynamics simulations. This work highlights hierarchical microstructures on mechanical response in nanosized metals and suggests small-scale engineering opportunities through AM-enabled microstructures.

vox_mundi

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Re: Material Science
« Reply #9 on: October 19, 2023, 02:46:35 AM »
“There are three classes of people: those who see. Those who see when they are shown. Those who do not see.” ― anonymous

Insensible before the wave so soon released by callous fate. Affected most, they understand the least, and understanding, when it comes, invariably arrives too late

morganism

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Re: Material Science
« Reply #10 on: December 05, 2023, 10:58:58 PM »

Low Temperature Liquid Metal Could Save 90% of Chemical Industry Energy
December 4, 2023 by Brian Wang

Chemical production using solid processes is energy intensive and causes over 10% of greenhouse emissions by requiring temperatures of up to a thousand degrees centigrade.
A new process instead uses liquid metals, in this case dissolving tin and nickel which gives them unique mobility, enabling them to migrate to the surface of liquid metals and react with input molecules such as canola oil. This results in the rotation, fragmentation, and reassembly of canola oil molecules into smaller organic chains, including propylene, a high-energy fuel crucial for many industries.

Reserarchers dissolved high melting point nickel and tin in a gallium based liquid metal with a melting point of only 30 degrees centigrade. Dissolving nickel in liquid gallium let them get access to liquid nickel at very low temperatures. This acts as a ‘super’ catalyst. In comparison solid nickel’s melting point is 1455 degrees centigrade. The same effect, to a lesser degree, is also experienced for tin metal in liquid gallium,” Dr Tang said.

The formula could also be used for other chemical reactions by mixing metals using the low temperature processes.

This could transform chemical engineering and reduce the use of energy by 90%.

https://www.nextbigfuture.com/2023/12/low-temperature-liquid-metal-could-save-90-of-chemical-industry-energy.html



morganism

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Re: Material Science
« Reply #11 on: December 17, 2023, 11:17:06 PM »
(New superhard nitride retains stability after release from anvil pressures. Also density multiples of TNT and RDX explosives)


New carbon nitride material challenges diamond's hardness throne.
(...)
 The study reveals that three different carbon nitride compounds were synthesized, each possessing the essential building blocks for super-hardness. Remarkably, these compounds retained their diamond-like qualities even when they were brought back to normal pressure and temperature conditions. This finding is pivotal as it showcases the stability and durability of these materials outside of laboratory conditions.

Dr. Dominique Laniel from the University of Edinburgh expressed astonishment at the discovery, stating, "Upon the discovery of the first of these new carbon nitride materials, we were incredulous to have produced materials researchers have been dreaming of for the last three decades." This sentiment was echoed by Dr. Florian Trybel from the University of Linkoping, who highlighted the multifunctionality of these materials and their potential to be recovered from synthesis pressures equivalent to those found deep within the Earth's interior.

Apart from their extraordinary hardness, these carbon nitrides also exhibit additional properties such as photoluminescence and high energy density, where a large amount of energy can be stored in a small amount of mass. This opens up a vast array of potential applications, positioning these ultra-incompressible carbon nitrides as ultimate engineering materials. They could find usage in various industrial sectors, including protective coatings for vehicles and spacecraft, high-endurance cutting tools, solar panels, and photodetectors.
(more)
https://www.energy-daily.com/reports/New_carbon_nitride_material_challenges_diamonds_hardness_throne_999.html



Synthesis of Ultra-Incompressible and Recoverable Carbon Nitrides Featuring CN4 Tetrahedra
Abstract

Carbon nitrides featuring three-dimensional frameworks of CN4 tetrahedra are one of the great aspirations of materials science, expected to have a hardness greater than or comparable to diamond. After more than three decades of efforts to synthesize them, no unambiguous evidence of their existence has been delivered. Here, the high-pressure high-temperature synthesis of three carbon-nitrogen compounds, tI14-C3N4, hP126-C3N4, and tI24-CN2, in laser-heated diamond anvil cells, is reported. Their structures are solved and refined using synchrotron single-crystal X-ray diffraction. Physical properties investigations show that these strongly covalently bonded materials, ultra-incompressible and superhard, also possess high energy density, piezoelectric, and photoluminescence properties. The novel carbon nitrides are unique among high-pressure materials, as being produced above 100 GPa they are recoverable in air at ambient conditions.

(more)
The recovery of complex materials synthesized above 100 GPa is a unique case–to the best of our knowledge a similar one has been never reported–and opens up new perspectives for high-pressure materials science in general. The carbon nitrides synthesized in this work are expected to exhibit multiple exceptional functionalities besides their mechanical properties, with the potential to be engineering materials in the same category as diamonds.[41] An insight into the possible prospects of these solids comes from our experiments, and from further theoretical calculations. In particular, sample #1, containing tI14-C3N4 and hP126-C3N4, appears visually transparent (Figure 1), pointing to insulating properties and wide band gaps of the compounds. This assessment is further supported by theoretical calculations at ambient conditions (Table S14 and Figures S14–S17, Supporting Information), showing that tI14-C3N4 and hP126-C3N4, but also oP8-CN and tI24-CN2, have wide band gaps (between 4.3 and 5.4 eV) comparable to diamond (5.48 eV).[42] However, contrary to diamond, tI24-CN2 is found to have a direct band gap. In addition, in the electronic structure of tI14-C3N4 and hP126-C3N4, one can clearly identify flat bands at the top of the valence band (Figures S15 and S16, Supporting Information). A theoretical analysis shows that the degree of the electron-electron correlation effects in tI14-C3N4 for the separated valence bands in the region from −3 to 0 eV is comparable to those in 3d-transition metals, like Ni[43] (see Supporting Information, electron-electron correlation effects, Figure S18, Supporting Information). Moreover, at a relatively low hole doping, a van Hove singularity in the hole density of states (Figure S15, Supporting Information) may lead to numerous competing channels of instabilities, such as charge density waves, itinerant magnetism, and others, with a very non-trivial interplay between them,[44, 45] making such systems highly attractive for further studies. Evidence supporting superconductivity below ≈55 K at ambient pressure in boron-doped tI14-C3N4 has been presented.[46]

The wide band gap nature of these materials, combined with the variability of their chemical compositions and crystal structures, leads to distinctive local chemical environments of the C and N atoms. From these environments, one can expect different properties of native and external defects. Photoluminescence measurements were performed on sample #1 (tI14-C3N4 and hP126-C3N4), sample #2 (oP8-CN), and sample #5 (hP126-C3N4) at ambient conditions using a green laser (532 nm, 2.33 eV) or a red laser (632.8 nm, 1.96 eV) as the excitation source. As seen in Figure S19, Supporting Information, from all of these samples very strong photoluminescence is observed. Given that the excitation energy is significantly smaller than the expected band gap of these materials, this directly suggests the presence of color centers and the possible tunability of the photoluminescence through defects.

Since the structures of tI14-C3N4 and tI24-CN2 are non-centrosymmetric, the compounds can exhibit piezoelectric properties. To gain further insight, DFT calculations were performed, which resulted in piezoelectric coefficients of −0.77 and −0.35 C m−2 for tI14-C3N4 and tI24-CN2, respectively (Table S15, Supporting Information). These values are two to four times greater than those of α-quartz (0.171 C m−2),[47] which is a standard piezoelectric material. The combination of piezoelectricity and superhardness distinguishes these two carbon nitrides from diamond and cubic boron nitride, and they could potentially be of use for smart and resilient cutting tools.[48] The non-centrosymmetric nature of the structure of these compounds also gives rise to non-linear optical properties such as second-order harmonic generation, as demonstrated from visual observations in Figure S20, Supporting Information.

Energy density calculations were performed for the four C–N compounds with respect to decomposition into graphite and molecular nitrogen, at ambient conditions. They revealed that they have a high gravimetric energy density, comparable to or higher than that of TNT for oP8-CN, tI14-C3N4, and hP126-C3N4, and for tI24-CN2, a value even higher than for RDX
(more)

https://onlinelibrary.wiley.com/doi/10.1002/adma.202308030

morganism

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Re: Material Science
« Reply #12 on: December 20, 2023, 07:04:56 PM »

Breakthrough Superconducting Devices With High Temperature Superconductors
December 18, 2023 by Brian Wang 

Kim, Harvard, and his fellow researchers have a promising candidate for the world’s first high-temperature, superconducting diode—essentially, a switch that makes current flow in one direction—made out of thin cuprate crystals. This would be the first superconducting switch made using higher temperature cuprate superconductors instead of lower temperature and more expensive superconductors.

The team’s experiments were led by S. Y. Frank Zhao, a former student at the Griffin Graduate School of Arts and Sciences and now a postdoctoral researcher at MIT. Using an air-free, cryogenic crystal manipulation method in ultrapure argon, Zhao engineered a clean interface between two extremely thin layers of the cuprate bismuth strontium calcium copper oxide, nicknamed BSCCO.

The team discovered that the maximum supercurrent that can pass without resistance through the interface is different depending on the current’s direction. Crucially, the team also demonstrated electronic control over the interfacial quantum state by reversing this polarity.

This control was what effectively allowed them to make a switchable, high-temperature superconducting diode—a demonstration of foundational physics that could one day be incorporated into a piece of computing technology, such as a quantum bit.

Journal Science – Twisted interfaces between stacked van der Waals (vdW) cuprate crystals present a platform for engineering superconducting order parameters by adjusting stacking angles. Employing a cryogenic assembly technique, we construct twisted vdW Josephson junctions (JJ) at atomically sharp interfaces between Bi2Sr2CaCu2O8+x crystals with quality approaching the limit set by intrinsic JJ. Near 45° twist angle, we observe fractional Shapiro steps and Fraunhofer patterns, consistent with the existence of two degenerate Josephson ground states related by time-reversal symmetry (TRS). By programming the JJ current bias sequence, we controllably break TRS to place the JJ into either of the two ground states, realizing reversible Josephson diodes without external magnetic fields. Our results open a path to engineering topological devices at higher temperatures.

https://www.nextbigfuture.com/2023/12/breakthrough-superconducting-devices-with-high-temperature-superconductors.html

morganism

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Re: Material Science
« Reply #13 on: January 17, 2024, 05:59:49 AM »
(a holy grail for robotics and limb repair, this is designed for micro-fluidics, but should be scalable)

(...(

 Switches based on existing motors were difficult to use within limited spaces due to their rigidity and large size. In order to address these issues, the research team developed an electro-ionic soft actuator that can control fluid flow while producing large amounts of force, even in a narrow pipe, and used it as a soft fluidic switch.

The ionic polymer artificial muscle developed by the research team is composed of metal electrodes and ionic polymers, and it generates force and movement in response to electricity. A polysulfonated covalent organic framework (pS-COF) made by combining organic molecules on the surface of the artificial muscle electrode was used to generate an impressive amount of force relative to its weight with ultra-low power (~0.01V).

As a result, the artificial muscle, which was manufactured to be as thin as a hair with a thickness of 180 um, produced a force more than 34 times greater than its light weight of 10 mg to initiate smooth movement. Through this, the research team was able to precisely control the direction of fluid flow with low power.

Professor IlKwon Oh, who led this research, said, "The electrochemical soft fluidic switch that operate at ultra-low power can open up many possibilities in the fields of soft robots, soft electronics, and microfluidics based on fluid control." He added, "From smart fibers to biomedical devices, this technology has the potential to be immediately put to use in a variety of industrial settings as it can be easily applied to ultra-small electronic systems in our daily lives."

https://www.energy-daily.com/reports/Artificial_muscle_device_produces_force_34_times_its_weight_999.html


Polysulfonated covalent organic framework as active electrode host for mobile cation guests in electrochemical soft actuator

https://www.science.org/doi/full/10.1126/sciadv.adk9752

Tailoring transfer dynamics of mobile cations across solid-state electrolyte-electrode interfaces is crucial for high-performance electrochemical soft actuators. In general, actuation performance is directly proportional to the affinity of cations and anions in the electrolyte for the opposite electrode surfaces under an applied field. Herein, to maximize electrochemical actuation, we report an electronically conjugated polysulfonated covalent organic framework (pS-COF) used as a common electrolyte-electrode host for 1-ethyl-3-methylimidazolium cation embedded into a Nafion membrane. The pS-COF–based electrochemical actuator exhibits remarkable bending deflection at near-zero voltage (~0.01 V) and previously unattainable blocking force, which is 34 times higher than its own weight. The ultrafast step response shows a very short rising time of 1.59 seconds without back-relaxation, and substantial ultralow-voltage actuation at higher frequencies up to 5.0 hertz demonstrates good application prospects of common electrolyte-electrode hosts. A soft fluidic switch is constructed using the proposed soft actuator as a potential engineering application.


morganism

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Re: Material Science
« Reply #14 on: January 19, 2024, 07:48:35 PM »
A faster and cheaper way to print metal nanostructures with light
(Nanowerk News) Researchers at the Georgia Institute of Technology have developed a light-based means of printing nano-sized metal structures that is significantly faster and cheaper than any technology currently available. It is a scalable solution that could transform a scientific field long reliant on technologies that are prohibitively expensive and slow. The breakthrough has the potential to bring new technologies out of labs and into the world.
Technological advances in many fields rely on the ability to print metallic structures that are nano-sized — a scale hundreds of times smaller than the width of a human hair. Sourabh Saha, assistant professor in the George W. Woodruff School of Mechanical Engineering, and Jungho Choi, a Ph.D. student in Saha’s lab, developed a technique for printing metal nanostructures that is 480 times faster and 35 times cheaper than the current conventional method.
Their research was published in the journal Advanced Materials ("Scalable Printing of Metal Nanostructures through Superluminescent Light Projection").
Printing metal on the nanoscale — a technique known as nanopatterning — allows for the creation of unique structures with interesting functions. It is crucial for the development of many technologies, including electronic devices, solar energy conversion, sensors, and other systems.
It is generally believed that high-intensity light sources are required for nanoscale printing. But this type of tool, known as a femtosecond laser, can cost up to half a million dollars and is too expensive for most research labs and small businesses.
“As a scientific community, we don’t have the ability to make enough of these nanomaterials quickly and affordably, and that is why promising technologies often stay limited to the lab and don’t get translated into real-world applications,” Saha said.
“The question we wanted to answer is, ‘Do we really need a high-intensity femtosecond laser to print on the nanoscale?’ Our hypothesis was that we don’t need that light source to get the type of printing we want.”
They searched for a low-cost, low-intensity light that could be focused in a way similar to femtosecond lasers, and chose superluminescent light emitting diodes (SLEDs) for their commercial availability. SLEDs emit light that is a billion times less intense than that of femtosecond lasers.
Saha and Choi set out to create an original projection-style printing technology, designing a system that converts digital images into optical images and displays them on a glass surface. The system operates like digital projectors but produces images that are more sharply focused. They leveraged the unique properties of the superluminescent light to generate sharply focused images with minimal defects.
They then developed a clear ink solution made up of metal salt and added other chemicals to make sure the liquid could absorb light. When light from their projection system hit the solution, it caused a chemical reaction that converted the salt solution into metal. The metal nanoparticles stuck to the surface of the glass, and the agglomeration of the metal particles creates the nanostructures. Because it is a projection type of printing, it can print an entire structure in one go, rather than point by point — making it much faster.
After testing the technique, they found that projection-style nanoscale printing is possible even with low-intensity light, but only if the images are sharply focused. Saha and Choi believe that researchers can readily replicate their work using commercially available hardware. Unlike a pricey femtosecond laser, the type of SLED that Saha and Choi used in their printer costs about $3,000.
“At present, only top universities have access to these expensive technologies, and even then, they are located in shared facilities and are not always available,” Choi said. “We want to democratize the capability of nanoscale 3D printing, and we hope our research opens the door for greater access to this type of process at a low cost.”
The researchers say their technique will be particularly useful for people working in the fields of electronics, optics, and plasmonics, which all require a variety of complex metallic nanostructures.
“I think the metrics of cost and speed have been greatly undervalued in the scientific community that works on fabrication and manufacturing of tiny structures,” Saha said.
“In the real world, these metrics are important when it comes to translating discoveries from the lab to industry. Only when we have manufacturing techniques that take these metrics into account will we be able to fully leverage nanotechnology for societal benefit.”

https://www.nanowerk.com/nanotechnology-news3/newsid=64459.php


Scalable Printing of Metal Nanostructures through Superluminescent Light Projection

Direct printing of metallic nanostructures is highly desirable but current techniques cannot achieve nanoscale resolutions or are too expensive and slow. Photoreduction of solvated metal ions into metallic nanoparticles is an attractive strategy because it is faster than deposition-based techniques. However, it is still limited by the resolution versus cost tradeoff because sub-diffraction printing of nanostructures requires high-intensity light from expensive femtosecond lasers. Here, this tradeoff is overcome by leveraging the spatial and temporal coherence properties of low-intensity diode-based superluminescent light. The superluminescent light projection (SLP) technique is presented to rapidly print sub-diffraction nanostructures, as small as 210 nm and at periods as small as 300 nm, with light that is a billion times less intense than femtosecond lasers. Printing of arbitrarily complex 2D nanostructured silver patterns over 30 µm × 80 µm areas in 500 ms time scales is demonstrated. The post-annealed nanostructures exhibit an electrical conductivity up to 1/12th that of bulk silver. SLP is up to 480 times faster and 35 times less expensive than printing with femtosecond lasers. Therefore, it transforms nanoscale metal printing into a scalable format, thereby significantly enhancing the transition of nano-enabled devices from research laboratories into real-world applications.

https://onlinelibrary.wiley.com/doi/10.1002/adma.202308112

morganism

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Re: Material Science
« Reply #15 on: January 22, 2024, 03:14:51 AM »
How to Build Your Own Injection Molding Machine

Learn how two brothers made a desktop injection molding machine and use the takeaways from their process to build your own.

Many people don’t realize that an injection molding machine is something they can build themselves, even without a machine shop or other extensive setup. The hosts of the Canadian YouTube channel Action BOX—known to viewers as brothers Alan and Dave—described in one of their videos how they created a desktop injection molder called the INJEKTO.

Even though the YouTube channel only appeared on June 14, 2021, some of the videos have several million views. All the Action BOX content aims to show people how to do and build things, encouraging them to have ideas in the process.

Here’s an in-depth breakdown of what the Action BOX team did and why certain design decisions were made.



(more)

https://www.machinedesign.com/3d-printing-cad/article/21263614/how-to-build-your-own-injection-molding-machine

https://actionbox.ca/pages/injekto-2-0

morganism

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Re: Material Science
« Reply #16 on: February 02, 2024, 08:55:34 PM »
NASA Spinoff 2024 is out, highlighting space science integration into daily products

Spinoff highlights NASA technologies that benefit life on Earth in the form of commercial products. We’ve profiled more than 2,000 spinoffs since 1976 — there’s more space in your life than you think!

https://spinoff.nasa.gov/

https://spinoff.nasa.gov/Other%20Spinoff%20Resources

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Re: Material Science
« Reply #17 on: February 14, 2024, 11:28:06 PM »
(sputter coating tantulum with magnesium makes a more stable superconduting surface.)


 "While oxygen has a high affinity to tantalum, it is 'happier' to stay with the magnesium than with the tantalum," said Peter Sushko, one of the PNNL theorists. "So, the magnesium reacts with oxygen to form a protective magnesium oxide layer. You don't even need that much magnesium to do the job. Just two nanometers of thickness of magnesium almost completely blocks the oxidation of tantalum."

The scientists also demonstrated that the protection lasts a long time: "Even after one month, the tantalum is still in pretty good shape. Magnesium is a really good oxygen barrier," Liu concluded.

The magnesium had an unexpected beneficial effect: It "sponged out" inadvertent impurities in the tantalum and, as a result, raised the temperature at which it operates as a superconductor.

"Even though we are making these materials in a vacuum, there is always some residual gas-oxygen, nitrogen, water vapor, hydrogen. And tantalum is very good at sucking up these impurities," Liu explained. "No matter how careful you are, you will always have these impurities in your tantalum."

But when the scientists added the magnesium coating, they discovered that its strong affinity for the impurities pulled them out. The resulting purer tantalum had a higher superconducting transition temperature.

That could be very important for applications because most superconductors must be kept very cold to operate. In these ultracold conditions, most of the conducting electrons pair up and move through the material with no resistance.

"Even a slight elevation in the transition temperature could reduce the number of remaining, unpaired electrons," Liu said, potentially making the material a better superconductor and increasing its quantum coherence time.

"There will have to be follow-up studies to see if this material improves qubit performance," Liu said. "But this work provides valuable insights and new materials design principles that could help pave the way to the realization of large-scale, high-performance quantum computing systems.

https://www.energy-daily.com/reports/Magnesium_protects_tantalum_a_promising_material_for_making_qubits_999.html


Ultrathin Magnesium-Based Coating as an Efficient Oxygen Barrier for Superconducting Circuit Materials

https://onlinelibrary.wiley.com/doi/10.1002/adma.202310280

Scaling up superconducting quantum circuits based on transmon qubits necessitates substantial enhancements in qubit coherence time. Over recent years, tantalum (Ta) has emerged as a promising candidate for transmon qubits, surpassing conventional counterparts in terms of coherence time. However, amorphous surface Ta oxide layer may introduce dielectric loss, ultimately placing a limit on the coherence time. In this study, a novel approach for suppressing the formation of tantalum oxide using an ultrathin magnesium (Mg) capping layer is presented. Synchrotron-based X-ray photoelectron spectroscopy studies demonstrate that oxide is confined to an extremely thin region directly beneath the Mg/Ta interface. Additionally, it is demonstrated that the superconducting properties of thin Ta films are improved following the Mg capping, exhibiting sharper and higher-temperature transitions to superconductive and magnetically ordered states. Moreover, an atomic-scale mechanistic understanding of the role of the capping layer in protecting Ta from oxidation is established based on computational modeling. This work provides valuable insights into the formation mechanism and functionality of surface tantalum oxide, as well as a new materials design principle with the potential to reduce dielectric loss in superconducting quantum materials. Ultimately, the findings pave the way for the realization of large-scale, high-performance quantum computing systems.

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Re: Material Science
« Reply #18 on: February 20, 2024, 07:34:32 PM »
Breakthrough medical glue magically binds tissues stronger than ever

Researchers at the Wyss Institute and Harvard SEAS have pulled off a medical marvel, creating a revolutionary glue that instantly bonds hydrogels.

The innovation could allow for seamless attachment of bio-printed tissues, instant sealing of leaky wounds, and firm placement of implantable devices.

Hydrogels are versatile materials used in many biomedical applications due to their similarity to human tissues. These applications range from delivering drugs to healing wounds and building new tissues. Hydrogels are safe because they closely resemble the body's structure and chemistry.

However, joining these hydrogel polymers together quickly and reliably has been challenging. Current methods need improvement in strength and speed, often requiring complex, time-consuming processes.

Chitosan: The key to instant bonding

At the core of this innovation is chitosan, a natural polymer derived from the shells of crustaceans, such as shrimp and crabs. This material is known for its biocompatibility, biodegradability, and non-toxic nature, making it an ideal candidate for medical applications.

Here's how researchers used it: they applied a thin layer of chitosan to the surfaces of the hydrogels they want to connect. This layer quickly absorbs water from both hydrogels, causing its sugar molecules to mix with the polymer molecules in the gels.

This mixing creates strong, non-chemical bonds through electrostatic forces and hydrogen bonding between different molecules. These bonds are surprisingly strong and can withstand extreme pulling, making the connected hydrogels more durable and useful for various medical purposes.
Advantages over traditional methods

This new method for bonding hydrogels offers significant advantages :

    Speed: Unlike conventional methods that rely on slow chemical reactions, the chitosan-based approach works instantly. This makes it incredibly valuable in medical situations where timely intervention is crucial, such as during surgery.
    Strength: The resulting bonds formed through this method are notably stronger than those achieved through traditional means. This stronger adhesion translates to greater reliability and durability of the bonded hydrogels.
    Simplicity: The process avoids the complexities of conventional methods, which often involve intricate chemical reactions or potentially harmful substances. This simpler approach makes implementing it safer and easier, minimizing potential complications.
    Versatility: This technique allows it to bond the same type of hydrogels. It can effectively join different hydrogel layers, various polymers, and even other materials, significantly expanding its potential applications across various fields.

Implications for medical applications

Hydrogels' quick and efficient bonding unlocks novel possibilities in the medical field. These jelly-like materials, whose stiffness can be adjusted, allow us to engineer them to resemble the mechanical properties of specific tissues closely. This opens doors to various applications.

For instance, we can incorporate flexible electronics within these hydrogels for on-demand medical diagnostics. Additionally, this technique can create self-adhesive wraps, which are particularly useful for body parts that pose bandaging challenges.

Furthermore, the ability to bond hydrogels addresses a significant clinical obstacle: surgical adhesions. These unwanted bonds form between tissues after surgery, causing pain and complications.

Utilizing chitosan-bonded hydrogels can effectively create a barrier between tissues during surgery, minimizing the risk of these adhesions. This translates to faster healing, reduced pain, and fewer patient complications.

The findings of this innovative technique are published in the Proceedings of the National Academy of Sciences (PNAS).

https://interestingengineering.com/innovation/breakthrough-medical-glue-binds-tissues-stronger

https://wyss.harvard.edu/technology/tough-gel-adhesives-for-wound-healing/

https://www.eurekalert.org/news-releases/1034748

DOI
    10.1073/pnas.2304643121


edit:plasma infused hydrogels

(...)
The current standard treatments for chronic wounds involve antibiotics and silver dressings, each with significant drawbacks. The growing resistance to antibiotics presents a global health challenge, while concerns about silver-induced toxicity have led to a phase-out of silver dressings in Europe. Now, scientists have pioneered a groundbreaking treatment that replaces antibiotics and silver-based dressings with plasma, an ionized gas. This innovative approach, with a primary focus on diabetic foot ulcers, holds potential for broad application across various chronic wounds and even internal infections. The researchers are optimistic that this method could significantly transform the treatment of diabetic foot ulcers, internal wounds, and potentially cancerous tumors.

The treatment developed by a team of international scientists led by University of South Australia (Adelaide, Australia) focuses on enhancing the efficacy of hydrogel dressings using plasma. This technique involves enriching the plasma activation of hydrogels with a unique combination of chemical oxidants, aiding in the decontamination and healing of chronic wounds. Cold plasma ionized gas has already demonstrated its effectiveness in clinical trials, controlling infection and fostering healing. This efficacy can be attributed to the robust mix of reactive oxygen and nitrogen species (RONS) produced when plasma interacts and activates ambient air's oxygen and nitrogen molecules. Although plasma-activated hydrogel therapy (PAHT) has shown promising results, a significant challenge was infusing hydrogels with clinically effective RONS concentrations. The team addressed this by utilizing an innovative electrochemical method to enhance hydrogel activation.

The researchers demonstrated that plasma-activated hydrogel dressings loaded with RONS are remarkably potent, capable of eradicating common bacteria like E. coli and P. aeruginosa, often responsible for infected wounds. Furthermore, these plasma-activated hydrogels can also stimulate the body's immune system, supporting the fight against infections. Going forward, plasma technology could be adapted to treat cancerous tumors. It would involve injecting gels containing activated drugs into the body, with the active components being gradually released to improve treatment effectiveness and tumor penetration. The research team is now preparing for clinical trials, aiming to refine this electrochemical technology for
the treatment of human patients.

https://www.hospimedica.com/critical-care/articles/294800314/breakthrough-electrochemical-technology-to-revolutionize-treatment-of-internal-wounds-and-cancerous-tumors.html
« Last Edit: February 20, 2024, 08:37:34 PM by morganism »

morganism

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Re: Material Science
« Reply #19 on: February 24, 2024, 09:13:38 AM »
DVD’s New Cousin Can Store More Than a Petabit

A novel disc the size of a DVD can hold more than 1 million gigabits—roughly as much as is transmitted per second over the entire world’s Internet—by storing data in three dimensions as opposed to two, a new study finds.

Optical discs such as CDs and DVDs encode data using a series of microscopic pits. These pits, and the islands between them, together represent the 0s and 1s of binary code that computers use to symbolize information. CD, DVD, and Blu-ray players use lasers to read the data encoded in these discs.

Although optical discs are low in cost and highly durable, they are limited by the amount of data they can hold, which is usually stored in a single layer. Previously, scientists investigated encoding data on optical discs in many layers in three dimensions to boost their capacity. However, a key barrier that prior research faced was how the optics used to read and write this data were limited to roughly the size of the wavelengths of light they used.

Now scientists in China have developed a way to encode data on 100 layers in optical discs. In addition, the data is recorded using spots as small as 54 nanometers wide, roughly a tenth of the size of the wavelengths of visible light used to read and write the data.

All in all, a DVD-size version of the new disc has a capacity of up to 1.6 petabits—that is, 1.6 million gigabits. This is some 4,000 times as much data density as a Blu-ray disc and 24 times as much as the currently most advanced hard disks. The researchers suggest their new optical disc can enable a data center capable of exabit storage—a billion gigabits—to fit inside a room instead of a stadium-size space.

“The use of ultrahigh-density optical data storage technology in big data centers is now possible,” says Min Gu, professor of optical-electrical and computer engineering at the University of Shanghai for Science and Technology.
How to store a petabit on one disc

The strategy the researchers used to write the data relies on a pair of lasers. The first, a green 515-nanometer laser, triggers spot formation, whereas the second, a red 639-nm laser, switches off the writing process. By controlling the time between firing of the lasers, the scientists could produce spots smaller than the wavelengths of light used to create them.

The procedure used to create blank discs is compatible with conventional DVD mass production and can be completed within 6 minutes.

To read the data, the researchers again depended on a pair of lasers. The first, a blue 480-nm beam, can make spots fluoresce, while the second, an orange 592-nm light, switches off the fluorescence process. Precise control over the firing of these lasers can single out which specific nanometer-scale spot ends up fluorescing.

This new strategy depends on a novel light-sensitive material called AIE-DDPR that is capable of all these varied responses to different wavelengths of light. “It has been a 10-year effort searching for this kind of material,” Gu says. “The difficulty has been how the writing and reading processes affect each other in a given material—in particular, in a three-dimensional geometry.”

The scientists encoded data on layers each separated by 1 micrometer. They found that the writing quality stayed comparable across all the layers. “Personally, I was surprised that nanoscale writing-recoding and reading processes both work well in our newly invented material,” Gu says.

The researchers note that the entire procedure used to create blank discs made using AIE-DDPR films is compatible with conventional DVD mass production and can be completed within 6 minutes. Gu says these new discs may therefore prove to be manufacturable at commercial scales.

Currently, he says, the new discs have a writing speed of about 100 milliseconds and an energy consumption of microjoules to millijoules.

Still, Gu says, the researchers would like to see their new discs used in big data centers. As a result, they’re working to improve their new method’s writing speed and energy consumption. He suggests this may be possible using new, more energy-efficient recording materials. He says more layers in each disc may be possible in the future, using better lenses and fewer aberrations in their optics.

The scientists detailed their findings online 21 February in the journal Nature

https://spectrum.ieee.org/data-storage-petabit-optical-disc

morganism

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Re: Material Science
« Reply #20 on: March 03, 2024, 10:01:29 PM »
Graphene protects meta-material single layer indium for nano-electronics.)

(...)
 In Search of a Protective Coating
"We dedicated two years to finding a method to protect the sensitive indenene layer from environmental elements using a protective coating. The challenge was ensuring that this coating did not interact with the indenene layer," explains Cedric Schmitt, one of Claessen's doctoral students involved in the project. This interaction is problematic because when different types of atoms - from the protective layer and the semiconductor, for instance - meet, they react chemically at the atomic level, changing the material. This isn't a problem with conventional silicon chips, which comprise multiple atomic layers, leaving sufficient layers unaffected and hence still functional.

"A semiconductor material consisting of a single atomic layer such as indenene would normally be compromised by a protective film. This posed a seemingly insurmountable challenge that piqued our research curiosity," says Claessen. The search for a viable protective layer led them to explore van der Waals materials, named after the Dutch physicist Johannes Diderik van der Waals (1837-1923). Claessen explains: "These two-dimensional van der Waals atomic layers are characterized by strong internal bonds between their atoms, while only weakly bonding to the substrate. This concept is akin to how pencil lead made of graphite - a form of carbon with atoms arranged in honeycomb layers - writes on paper. The layers of graphene can be easily separated. We aimed to replicate this characteristic."

Success!
Using sophisticated ultrahigh vacuum equipment, the Wurzburg team experimented with heating silicon carbide (SiC) as a substrate for indenene, exploring the conditions needed to form graphene from it. "Silicon carbide consists of silicon and carbon atoms. Heating it causes the carbon atoms to detach from the surface and form graphene," says Schmitt, elucidating the laboratory process. "We then vapor-deposited indium atoms, which are immersed between the protective graphene layer and the silicon carbide substrate. This is how the protective layer for our two-dimensional quantum material indenene was formed."

Umbrella Unfurled
For the first time globally, Claessen and his team at ct.qmat's Wurzburg branch successfully crafted a functional protective layer for a two-dimensional quantum semiconductor material without compromising its extraordinary quantum properties. After analyzing the fabrication process, they thoroughly tested the layer's protective capabilities against oxidation and corrosion. "It works! The sample can even be exposed to water without being affected in any way," says Claessen with delight. "The graphene layer acts like an umbrella for our indenene."

Toward Atomic Layer Electronics
This breakthrough paves the way for applications involving highly sensitive semiconductor atomic layers. The manufacture of ultrathin electronic components requires them to be processed in air or other chemical environments. This has been made possible thanks to the discovery of this protective mechanism. The team in Wurzburg is now focused on identifying more van der Waals materials that can serve as protective layers - and they already have a few prospects in mind. The snag is that despite graphene's effective protection of atomic monolayers against environmental factors, its electrical conductivity poses a risk of short circuits. The Wurzburg scientists are working on overcoming these challenges and creating the conditions for tomorrow's atomic layer electronics.

https://www.energy-daily.com/reports/Umbrella_for_atoms_The_first_protective_layer_for_2D_quantum_materials_999.html


Achieving environmental stability in an atomically thin quantum spin Hall insulator via graphene intercalation

Atomic monolayers on semiconductor surfaces represent an emerging class of functional quantum materials in the two-dimensional limit — ranging from superconductors and Mott insulators to ferroelectrics and quantum spin Hall insulators. Indenene, a triangular monolayer of indium with a gap of ~ 120 meV is a quantum spin Hall insulator whose micron-scale epitaxial growth on SiC(0001) makes it technologically relevant. However, its suitability for room-temperature spintronics is challenged by the instability of its topological character in air. It is imperative to develop a strategy to protect the topological nature of indenene during ex situ processing and device fabrication. Here we show that intercalation of indenene into epitaxial graphene provides effective protection from the oxidising environment, while preserving an intact topological character. Our approach opens a rich realm of ex situ experimental opportunities, priming monolayer quantum spin Hall insulators for realistic device fabrication and access to topologically protected edge channels.

https://www.nature.com/articles/s41467-024-45816-9

morganism

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Re: Material Science
« Reply #21 on: March 04, 2024, 07:40:29 PM »
Basic Principle of Physics Is Wrong, Oxford Scientists Say
(...)
Researchers from the University of Oxford's chemistry department found that like-charged particles submerged in solutions were able to attract each other from long distances, depending on the solvent used and the sign of the charge.

The study has been published in the journal Nature Nanotechnology.

Researchers believe their study will change the way scientists think about processes such as how medicines and chemicals stay stable or how certain diseases develop. They also discovered a way to measure properties of the electrical charge caused by solvents, which was previously thought impossible.
(snip)
The researchers tracked negatively charged silica microparticles that were suspended in a solution and discovered that these particles did indeed attract each other, forming hexagonally arranged clusters when they did.

"I still find it fascinating to see these particles attract, even having seen this a thousand times," Sida Wang, the first author on the study, said.

Although these negatively charged particles attracted each other, positively charged ones did not.

The scientists believe the phenomenon is caused by an attractive force only present in water that outweighs the usual electrostatic repulsion, allowing these clusters to form.
This attractive force had no effect on positively charged particles in water, however.

Scientists found that they were able to manipulate the formation of these clusters by varying the Ph (acidity). However, no matter what the Ph was, the positively charged particles still did not attract.

Throughout the study the team also wondered whether the effect on these charged particles could be changed when the solvent was changed.

When they changed the solution to alcohol rather than water, they observed positively charged silica particles forming these clusters, while negatively charged particles did not.

"Here we demonstrate experimentally that the solvent plays a hitherto unforeseen but crucial role in interparticle interactions, and importantly, that interactions in the fluid phase can break charge-reversal symmetry," the study's authors wrote.

"We show that in aqueous solution, negatively charged particles can attract at long range while positively charged particles repel. In solvents that exhibit an inversion of the net molecular dipole at an interface, such as alcohols, we find that the converse can be true: positively charged particles may attract whereas negatives repel."

(newsweek news, no link to study provided. This has very interesting implications for exo-bio and the start of life)

morganism

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Re: Material Science
« Reply #22 on: March 07, 2024, 01:59:49 AM »
Superconductors Posted by SCT Corp
March 6, 2024 by Brian Wang

SCT Corp is a different South Korean group from the original Korean team working on room temperature superconductors. Dae-Chel Jung is one of the researchers are SCT Corp.

SCT Corp provided a video of one of their superconducting samples fully levitating. SCTL is short for Superconducting Technology Lab and SCT Corp is Superconductor Technology Corp.

There will be a research paper published onto arxiv by this team in the next few days.

The key difference between LK-99’s chemical formula — Pb10−xCux (PO4) 6O — and that of PCPOSOS — Pb10-xCux (P (O1-ySy) 4) 6O1-zSz — is the addition of sulfur, which partially substitutes oxygen atoms.

https://www.nextbigfuture.com/2024/03/video-discussion-lk99-type-room-temperature-superconductor-full-levitation.html

morganism

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Re: Material Science
« Reply #23 on: March 16, 2024, 08:42:35 AM »
(i think this was an old Wired article from 2018. could be interesting in the Helion Energy fusion model. Dont know if a plasma gonna have the effect of a BEC, but...)


Bose-Einstein and Anti-Gravity

In the 1980s, Ning-Li – a world renowned scientist predicted that if a time-varying magnetic field were applied to superconductor ions trapped in a lattice structure, the ions would absorb enormous amounts of energy. Confined in the lattice, the ions would begin to rapidly spin, causing each to create a minuscule gravitational field.

It wouldn’t actually be an anti-gravity machine’ it would, however, be exerting an attractive or repulsive force on all matter and would therefore be pretty close to an impossible machine.

Dr Ning Li, working in UAH’s Centre for Space Plasma and Aeronomic Research has recently been working at UAH on an ‘artificial’ gravitational field made inside a container made of superconducting material.

    “If Einstein was right, the amount of gravito-magnetic energy produced by an object is proportional to its mass and its movement”, explains Dr. Li. To create the artificial gravitational fields, Torr and Li propose placing a superconducting container in a magnetic field to align ions that are spinning or rotating in tiny circles inside the superconducting material. Their theory predicts the existence of ionic spin or rotation in a superconductor in a magnetic field.

    To understand how an HTSD (The high temperature superconducting disk) is critical to the construction of a force-field machine, it’s useful to know something about an unusual state of matter called a Bose-Einstein condensate. In our day-to-day lives we encounter three states of matter: solid, liquid and gas. In the laboratory it is possible to create another state of matter in which all the atoms are aligned in a way that makes them behave as if they were one single atom. This unique state of matter is named after Albert Einstein and Indian physicist Satyendra Nath Bose who predicted its existence decades ago. The Bose-Einstein condensate is essentially when many atoms squeeze into a small space.The first time it was produced about 2000 Rubidium atoms fitted into a 20 micron space. These experiments were run at a temperature as close to absolute zero that science will allow due to quantum mechanics and thermodynamics. The high temperature superconducting disk (HTSD) allows for each atom to produce a gravitational effect six orders of magnitude higher than usual. Because of the small mass of an atom the acceleration must compensate in order to make a strong enough force. Atoms spin very quickly and in a Bose-Einstein condensate enough atoms come together to form a force that is perpendicular to the spin of the atom. This produces a gravity-like field, which could be controlled in any direction.

    In an HTSD, the tiny gravitational effect of each individual atom is multiplied by the billions of atoms in the disc. Using about one kilowatt of electricity, Li says, her device could potentially produce a force field that would effectively neutralize gravity above a 1-ft.-dia. region extending from the surface of the planet to outer space.

    Li describes her device as a method of generating a never-before-seen force field that acts on matter in a way that is similar to gravity. Since it may be either repulsive or attractive she calls it “AC gravity.”

    Larry Smalley, the former chairman of the University of Alabama at Huntsville (UAH) physics department says of this work “Basically, you are adding a couple of vectors to zero it [gravity] out or enhance it.”

Interestingly, Einstein’s theory of relativity predicts this effect. All objects produce gravito-magnetic energy, the amount of force proportional to its mass and acceleration. Li says that the main reason this energy has never been detected is that the Earth spins very slowly and the field’s strength decreases rapidly as you move away from the center of the planet.
Beginning with the most basic law of physics-force = mass x acceleration-Li reasoned that it would be possible to perform the same experiment here on Earth, using ions locked in the aforementioned lattice structure inside a superconductor because when an ion rotates around a magnetic field, the mass goes along for the ride. This, according to Einstein, should produce the gravito-magnetic field.

Ions, unlike Earth, have a minuscule mass. But another important difference to the Earth is that they spin very quickly, rotating more than a quadrillion times a second, compared to our planet’s 24 hour rotation. Li calculates this movement will compensate for the small mass of the ions.

Li explains that as the ions spin they also create a gravito-electric field perpendicular to their spin axis. In nature, this field is unobserved because the ions are randomly arranged, thus causing their tiny gravito-electric fields to cancel out one another. In a Bose-Einstein condensate, where all ions behave as one, something very different occurs.

Li says that if the ions in an HTSD are aligned by a magnetic field, the gravito-electric fields they create should also align. Build a large enough disc and the cumulative field should be measurable. Build a larger disc and the force field above it should be controllable –something pointable in any direction.

Li’s theory has passed through the scientific quality-control peer review process and an HTSD has been constructed, but important technical unknowns remain. Li has since left UAH. She and several colleagues are striking out on their own to commercialize devices based on her theory and a proprietary HTSD fabrication technique. Public money goes private again?

Li’s next step is to raise the several million dollars needed to build the induction motor that individually spins the ions in the HTSD. “It will take at least two years to simulate the machine on a computer,” says Smalley, who plans to join Li’s as-yet-unnamed company after he retires from UAH. “We want to avoid the situation that occurred in fusion where extremely expensive reactors were built, turned on, and didn’t work as intended because of unforeseen plasma instabilities.” Li says she has turned down several offers for financial backing. It is less about money than control. “Investors want control over the technology,” she says. “This is too important. It should belong to all the American people.”

morganism

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Re: Material Science
« Reply #24 on: March 22, 2024, 06:22:04 PM »
(Brian Wang from NBFuture has a vid up on the latest China report on LK99 ,20 mins)

https://www.nextbigfuture.com/2024/03/brians-video-talk-about-chinas-lk99-type-research.html#more-194165




morganism

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Re: Material Science
« Reply #25 on: March 25, 2024, 01:27:34 AM »
Nodal superconductivity in miassite Rh17S15 

Materials that can display superconductivity are extremely rare in nature. Although some elements are found in metallic form, superconductivity has only been reported in meteorites that contain alloys of tin, lead, and indium1. Superconducting compounds are even scarcer, and only the mineral covellite, CuS, shows superconductivity in samples that occur naturally2, a discovery that occurred many decades after superconductivity was first detected in laboratory-grown CuS crystals3. We know of only three other minerals where synthetic analogs are superconductors: parkerite, Ni3Bi2S2, with superconducting transition temperature, Tc ≈ 0.7 K4,5, and two isostructural compounds, miassite, Rh17S15 (Tc = 5.8 K)6, and palladseite, Pd17Se15 (Tc = 2.2 K)7. Here, we study the superconducting properties of synthetic miassite, which is also one of the few rhodium-containing minerals. Initially believed to have Rh9S8 composition, this compound was first synthesized in the 1930s8, and superconductivity in polycrystals was reported in 1954 by Matthias et al.6. Stoichiometry was refined to Rh17S15 in the early 1960s9. A mineral with the same composition was discovered significantly later in the placers of the Miass River in the Ural Mountains in Russia, from which it derives its name10,11. Natural miassite is found in isoferroplatinum deposits as small rounded inclusions up to 100 μm in diameter12. The natural mineral contains a large amount of impurities, such as iron, nickel, platinum, and copper, at a level of a few atomic percent13.

The superconducting properties of miassite display a number of remarkable features. It is exceptional among the naturally occurring superconductors, showing an anomalously high upper critical field greater than 20 T14, exceeding the Pauli limit of about 10 T. In contrast, the upper critical field of palladseite is about 3.3 T, below the Pauli limit7, while in elemental superconductors, covellite2,15 and parkerite4 the upper critical field is orders of magnitude smaller. The heat capacity jump at Tc is reported to significantly exceed the prediction of the weak-coupling Bardeen–Cooper–Schrieffer (BCS) theory11. The electronic heat capacity in the normal state shows a large Sommerfeld coefficient11,16, comparable to heavy-fermion superconductors17 and probably originates from Rh d-electrons18. The low-temperature variation of the heat capacity measured in single crystals deviates from the exponential attenuation expected in a fully gapped superconductor7, contradicting previous findings in polycrystalline samples16. The Hebel–Schlichter peak is notably absent in Rh17S15, contrary to expectations for s-wave superconductivity16. We note that the experimental results in the isostructural palladseite are much more consistent with the BCS s-wave theory7. Finally, there is an order of magnitude difference between the coherence length of about 4 nm derived from Hc2(0), and the BCS length scale ξ0 ≈ 39 nm, which is at least ten times greater. In the weak-coupling BCS theory, in the clean limit (which we prove is the case here), these two lengths are of the same order, ξ = 0.87ξ0 for isotropic s-wave19 and similarly, with a slightly different numerical prefactor, for arbitrary k-dependent order parameter, including d-wave20. Therefore, an extremely high Hc2(0) alone represents a significant departure from the BCS theory.

The unusual experimental observations in Rh17S15 motivated us to clarify its superconducting pairing state. In this report, we present strong evidence for an unconventional gap structure in Rh17S15. Our discovery is based on measurements of the temperature-dependent London penetration depth, down to ~Tc/100, and the response to non-magnetic disorder. London penetration depth shows T-linear variation below Tc/3, consistent with the line nodes in the superconducting order parameter21,22. Further evidence of a nodal gap is provided by the significant suppression of Tc and Hc2 by non-magnetic defects induced by 2.5 MeV electron irradiation. Our results are consistent with an extended s-wave state that has circular line nodes. The existence of gap nodes is a hallmark of unconventional superconductivity, observed in cuprates21,23, some iron pnictides24,25,26,27, heavy-fermions17, and possibly organic superconductors28. All of these materials are products of synthetic solid-state chemistry and are not found in nature. Our work establishes Rh17S15 as a unique member of the unconventional superconductors, being the only example that occurs as a natural mineral.

https://www.nature.com/articles/s43246-024-00456-w?CJEVENT=659d3bf3ea3d11ee83439fbf0a1cb829


https://www.popularmechanics.com/science/a60216120/superconductor-found-in-nature/

morganism

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Re: Material Science
« Reply #26 on: April 17, 2024, 03:19:07 AM »
 The Tiny Ultrabright Laser that Can Melt Steel

Photonic crystals are the key to the brightest semiconductor laser ever


(snip)
 The magic of PCSELs arises from their unique construction. Like any semiconductor laser, a PCSEL consists of a thin layer of light-generating material, known as the active layer, sandwiched between cladding layers. In fact, for the sake of orientation, it’s helpful to picture the device as a literal sandwich—let’s say a slice of ham between two pieces of bread.

Now imagine lifting the sandwich to your mouth, as if you are about to take a bite. If your sandwich were a conventional semiconductor laser, its beam would radiate from the far edge, away from you. This beam is created by passing a current through a stripe in the active “ham” layer. The excited ham atoms spontaneously release photons, which stimulate the release of identical photons, amplifying the light. Mirrors on each end of the stripe then repeatedly reflect these waves; because of interference and loss, only certain frequencies and spatial patterns—or modes—are sustained. When the gain of a mode exceeds losses, the light emerges in a coherent beam, and the laser is said to oscillate in that mode.

The problem with this standard stripe approach is that it is very difficult to increase output power without sacrificing beam quality. The power of a semiconductor laser is limited by its emission area because extremely concentrated light can cause catastrophic damage to the semiconductor. You can deliver more power by widening the stripe, which is the strategy used for so-called broad-area lasers. But a wider stripe also gives room for the oscillating light to take zigzag sideways paths, forming what are called higher-order lateral modes.

Those troublesome modes are why the brightness of conventional semiconductor lasers maxes out around 100 MW/cm2/sr. PCSELs deal with unwanted modes by adding another layer inside the sandwich: the “Swiss cheese” layer. This special extra layer is a semiconductor sheet stamped with a two-dimensional array of nanoscale holes. By tuning the spacing and shape of the holes, we can control the propagation of light inside the laser so that it oscillates in only the fundamental mode, even when the emission area is expanded. The result is a beam that can be both powerful and narrow—that is, bright.

Because of their internal physics, PCSELs operate in a completely different way from edge-emitting lasers. Instead of pointing away from you, for instance, the beam from your PCSEL sandwich would now radiate upward, through the top slice of bread. To explain this unusual emission, and why PCSELs can be orders of magnitude brighter than other semiconductor lasers, we must first describe the material properties of the Swiss cheese—in actuality, a fascinating structure called a photonic crystal.
How Photonic Crystals Work

Photonic crystals control the flow of light in a way that’s similar to how semiconductors control the flow of electrons. Instead of atoms, however, the lattice of a photonic crystal is sculpted out of larger entities—such as holes, cubes, or columns—arranged such that the refractive index changes periodically on the scale of a wavelength of light. Although the quest to artificially construct these marvelous materials began less than 40 years ago, scientists have since learned that they already exist in nature. Opals, peacock feathers, and some butterfly wings, for example, all owe their brilliant iridescence to the intricate play of light within naturally engineered photonic crystals.

Understanding how light moves in a photonic crystal is fundamental to PCSEL design. We can predict this behavior by studying the crystal’s photonic band structure, which is analogous to the electronic band structure of a semiconductor. One way to do that is to plot the relationship between frequency and wavenumber—the number of wave cycles that fit within one unit cell of the crystal’s lattice.
(more)

https://spectrum.ieee.org/pcsel