New Plastic Conducts Electricity Like Metal

Calendar October 28, 2022 | Posted by admin

Scientists with the University of Chicago have discovered a way to create a material that can be made like a plastic, but conducts electricity more like a metal. The research, published Oct. 26 in Nature, shows how to make a kind of material in which the molecular fragments are jumbled and disordered, but can still conduct electricity extremely well.

This goes against all of the rules we know about for conductivity—to a scientist, it’s kind of seeing a car driving on water and still going 70 mph. But the finding could also be extraordinarily useful; if you want to invent something revolutionary, the process often first starts with discovering a completely new material.

“In principle, this opens up the design of a whole new class of materials that conduct electricity, are easy to shape, and are very robust in everyday conditions,” said John Anderson, an associate professor of chemistry at the University of Chicago and the senior author on the study. “Essentially, it suggests new possibilities for an extremely important technological group of materials,” said Jiaze Xie (PhD’22, now at Princeton), the first author on the paper.

You must be logged in to view this content.

Category Categories: Uncategorized  |  Tag Tags: , , , , , , , , , , , , , , , ,

Quantum Entanglement Wins 2022’s Nobel Prize

Calendar October 6, 2022 | Posted by admin

For generations, scientists argued over whether there was truly an objective, predictable reality for even quantum particles, or whether quantum “weirdness” was inherent to physical systems. In the 1960s, John Stewart Bell developed an inequality describing the maximum possible statistical correlation between two entangled particles: Bell’s inequality. But certain experiments could violate Bell’s inequality, and these three pioneers —  John Clauser, Alain Aspect, and Anton Zeilinger — helped make quantum information systems a bona fide science.

There’s a simple but profound question that physicists, despite all we’ve learned about the Universe, cannot fundamentally answer: “What is real?” We know that particles exist, and we know that particles have certain properties when you measure them. But we also know that the very act of measuring a quantum state — or even allowing two quanta to interact with one another — can fundamentally alter or determine what you measure. An objective reality, devoid of the actions of an observer, does not appear to exist in any sort of fundamental way.

But that doesn’t mean there aren’t rules that nature must obey. Those rules exist, even if they’re difficult and counterintuitive to understand. Instead of arguing over one philosophical approach versus another to uncover the true quantum nature of reality, we can turn to properly-designed experiments. Even two entangled quantum states must obey certain rules, and that’s leading to the development of quantum information sciences: an emerging field with potentially revolutionary applications. 2022’s Nobel Prize in Physics was just announced, and it’s awarded to John Clauser, Alain Aspect, and Anton Zeilinger for the pioneering development of quantum information systems, entangled photons, and the violation of Bell’s inequalities. It’s a Nobel Prize that’s long overdue, and the science behind it is particularly mind-bending.

There are all sorts of experiments we can perform that illustrate the indeterminate nature of our quantum reality.

Place a number of radioactive atoms in a container and wait a specific amount of time. You can predict, on average, how many atoms will remain versus how many will have decayed, but you have no way of predicting which atoms will and won’t survive. We can only derive statistical probabilities.
Fire a series of particles through a narrowly spaced double slit and you’ll be able to predict what sort of interference pattern will arise on the screen behind it. However, for each individual particle, even when sent through the slits one at a time, you cannot predict where it will land.
Pass a series of particles (that possess quantum spin) through a magnetic field and half will deflect “up” while half deflect “down” along the direction of the field. If you don’t pass them through another, perpendicular magnet, they’ll maintain their spin orientation in that direction; if you do, however, their spin orientation will once again become randomized.
Certain aspects of quantum physics appear to be totally random. But are they really random, or do they only appear random because our information about these systems are limited, insufficient to reveal an underlying, deterministic reality? Ever since the dawn of quantum mechanics, physicists have argued over this, from Einstein to Bohr and beyond.

Source: https://bigthink.com/

Category Categories: Uncategorized  |  Tag Tags: , , , , , , , , , , , , ,

Nano-Transistor From DNA-like Material

Calendar February 24, 2020 | Posted by admin

Computer chips use billions of tiny switches, called transistors, to process information. The more transistors on a chip, the faster the computer. A material shaped like a one-dimensional DNA helix might further push the limits on a transistor’s size. The material comes from a rare earth element called tellurium.

Researchers found that the material, encapsulated in a nanotube made of boron nitride, helps build a field-effect transistor with a diameter of two nanometers. Transistors on the market are made of bulkier silicon and range between 10 and 20 nanometers in scale.  Engineers at Purdue University performed the work in collaboration with Michigan Technological University, Washington University in St. Louis, and the University of Texas at Dallas.

Over the past few years, transistors have been built as small as a few nanometers in lab settings. The goal is to build transistors the size of atoms. Peide Ye’s lab at Purdue is one of many research groups seeking to exploit materials much thinner than silicon to achieve both smaller and higher-performing transistors.

These silver, wiggling lines are strings of atoms in tellurium behaving like DNA. Researchers have not seen this behavior in any other material.

“This tellurium material is really unique. It builds a functional transistor with the potential to be the smallest in the world,” said Ye, Purdue’s Richard J. and Mary Jo Schwartz Professor of Electrical and Computer Engineering.

The research is published in the journal Nature Electronics.

Source: https://www.purdue.edu/

Category Categories: Uncategorized  |  Tag Tags: , , , , , , , , , , , , , ,

Smart Materials Built With The Power Of Sound

Calendar June 17, 2019 | Posted by admin

Researchers have used sound waves to precisely manipulate atoms and molecules, accelerating the sustainable production of breakthrough smart materials.  Metal Organic Frameworks, or MOFs, are incredibly versatile and super porous nanomaterials that can be used to store, separate, release or protect almost anything. Predicted to be the defining material of the 21st century, MOFs are ideal for sensing and trapping substances at minute concentrations, to purify water or air, and can also hold large amounts of energy, for making better batteries and energy storage devices. Scientists have designed more than 88,000 precisely-customised MOFs – with applications ranging from agriculture to pharmaceuticals – but the traditional process for creating them is environmentally unsustainable and can take several hours or even days. 

Now researchers from RMIT in Australia have demonstrated a clean, green technique that can produce a customised MOF in minutes. Dr Heba Ahmed, lead author of the study published in Nature Communications, said the efficient and scaleable method harnessed the precision power of high-frequency sound waves.

Dr Heba Ahmed holding a MOF created with high-frequency sound waves

“MOFs have boundless potential, but we need cleaner and faster synthesis techniques to take full advantage of all their possible benefits,” Ahmed, a postdoctoral researcher in RMIT’s Micro/Nanophysics Research Laboratory, said. “Our acoustically-driven approach avoids the environmental harms of traditional methods and produces ready-to-use MOFs quickly and sustainably. “The technique not only eliminates one of the most time-consuming steps in making MOFs, it leaves no trace and can be easily scaled up for efficient mass production.”

Metal-organic frameworks are crystalline powders full of tiny, molecular-sized holes. They have a unique structure – metals joined to each other by organic linkers – and are so porous that if you took a gram of a MOF and spread out its internal surface area, you would cover an area larger than a football pitch. Some have predicted MOFs could be as important to the 21st  century as plastics were to the 20th.

During the standard production process, solvents and other contaminants become trapped in the MOF’s holes. To flush them out, scientists use a combination of vacuum and high temperatures or harmful chemical solvents in a process called “activation”. In their novel technique, RMIT researchers used a microchip to produce high-frequency sound waves. Co-author and acoustic expert Dr Amgad Rezk said these sound waves, which are not audible to humans, can be used for precision micro- and nano-manufacturing.

“At the nano-scale, sound waves are powerful tools for the meticulous ordering and manoeuvring of atoms and molecules,” Rezk said.

Source: https://www.rmit.edu.au/

Category Categories: Uncategorized  |  Tag Tags: , , , , , , , , ,