Category Archives: Uncategorized

Nanotubes Boost Batteries Efficiency

The Rice lab of chemist James Tour showed thin nanotube films effectively stop dendrites that grow naturally from unprotected lithium metal anodes in batteries. Over time, these tentacle-like dendrites can pierce the battery’s electrolyte core and reach the cathode, causing the battery to fail. That problem has both dampened the use of lithium-metal  in commercial applications and encouraged researchers worldwide to solve it.

Lithium metal charges much faster and holds about 10 times more energy by volume than the lithium-ion electrodes found in just about every electronic device, including cellphones and electric cars.

Microscope images of lithium metal anodes after 500 charge/discharge cycles in tests at Rice University show the growth of dendrites is quenched in the anode at left, protected by a film of carbon nanotubes. The unprotected lithium metal anode at right shows evidence of dendrite growth

One of the ways to slow dendrites in lithium-ion batteries is to limit how fast they charge,” Tour said. “People don’t like that. They want to be able to charge their batteries quickly.”

The Rice team’s answer, detailed in Advanced Materials, is simple, inexpensive and highly effective at stopping dendrite growth, Tour said. “What we’ve done turns out to be really easy,” he said. “You just coat a lithium metal foil with a multiwalled carbon nanotube film. The lithium dopes the nanotube film, which turns from black to red, and the film in turn diffuses the lithium ions.

Source: http://news.rice.edu/

Man With Multiple Sclerosis Walks Again After Stem Cell Transplant

For a decade, Roy Palmer had no control of his legs. The man from Gloucester, England, had multiple sclerosis, or MS, which results in the body’s immune system eating away at the protective covering of nerves, disrupting communication between the brain and the body.  Palmer had no feeling in his legs and used a wheelchair. But last year, he received a life-changing treatment that restored his ability to walk — and dance — again,the BBC reports. The dad first heard of the treatment, called HSCT (hematopoietic stem cell transplantation), on the BBC program, “Panorama.”

Two people on that program went into Sheffield Hospital in wheelchairs and they both came out walking,” Palmer said. “As soon as we saw that, we both cried,” Palmer’s wife told the BBC. According to the National MS Society, HSCT still considered experimental, but Palmer decided it was worth a try.

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If they can have that done, on a trial, why can’t I have it done?” Palmer said. So last year, the 49-year-old started the grueling treatment, which is potentially risky, the BBC reports. HSCT doesn’t always work and there is a long-term risk of infection and infertility. “They take the stem cells out of your body. They give you chemotherapy to kill the rest of your immune system,” Palmer told the BBC. The stem cells are then used to reboot the immune system. “Let’s hope it works,” Palmer adds in a home video taken just before the treatment. It did. After HSCT, he regained feeling in his left leg within two days. “I haven’t felt that in 10 years,” comments Palmer. “It’s a miracle.” Eventually, he regained feeling in both of his legs and began to walk.

Source: https://www.cbsnews.com/

Cheap High-Performance Catalysts For Hydrogen Electric Car

The industry has been traditionally deploying platinum alloys as catalysts for oxygen reduction, which is for example essential in fuel cells or metal-air batteries. Expensive and rare, that metal imposes strict restrictions on manufacture. Researchers at Ruhr-Universität Bochum (RUB) and Max-Planck-Institut für Eisenforschung in Germany have discovered an alloy made up of five elements that is noble metal-free and as active as platinum.  The catalytic properties of non-noble elements and their alloys are usually rather poor. To the researchers’ surprise, one alloy made up of five almost equally balanced components offer much better properties. This is because of the so-called high entropy effect. It causes multinary alloys to maintain a simple crystal structure.

Through the interaction of different neighbouring elements, new active centres are formed that present entirely new properties and are therefore no longer bound to the limited properties of the individual elements,” explains Tobias Löffler, PhD student at the RUB Chair of Analytical ChemistryCenter for Electrochemical Sciences headed by Professor Wolfgang Schuhmann. “Our research has demonstrated that this alloy might be relevant for catalysis.”

Headed by Professor Christina Scheu, the research team at the Max-Planck-Institut für Eisenforschung analysed the generated nanoparticles using transmission electron microscopy. RUB chemists determined their catalytic activity and compared it with that of platinum nanoparticles. In the process, they identified a system made of up five elements where the high entropy effect results in catalytic activity for an oxygen reduction that is similar to that of platinum. By optimising the composition further, they successfully improved the overall activity.

These findings may have far-reaching consequences for electrocatalysis in general,” surmises Wolfgang Schuhmann. The researchers are hoping to adapt the properties for any required reactions by taking advantage of the almost infinite number of possible combinations of the elements and modifications of their composition. “Accordingly, the application will not necessarily be limited to oxygen reduction,” says Ludwig. The research team has already applied for a patent.

The results are published in the journal Advanced Energy Materials.

Source: http://news.rub.de/

How to mass produce cell-sized robots

NanoRobots no bigger than a cell could be mass-produced using a new method developed by researchers at MIT. The microscopic devices, which the team calls “syncells” (short for synthetic cells), might eventually be used to monitor conditions inside an oil or gas pipeline, or to search out disease while floating through the bloodstream.

The key to making such tiny devices in large quantities lies in a method the team developed for controlling the natural fracturing process of atomically-thin, brittle materials, directing the fracture lines so that they produce miniscule pockets of a predictable size and shape. Embedded inside these pockets are electronic circuits and materials that can collect, record, and output data.  The system uses a two-dimensional form of carbon called graphene, which forms the outer structure of the tiny syncells. One layer of the material is laid down on a surface, then tiny dots of a polymer material, containing the electronics for the devices, are deposited by a sophisticated laboratory version of an inkjet printer. Then, a second layer of graphene is laid on top.

This photo shows circles on a graphene sheet where the sheet is draped over an array of round posts, creating stresses that will cause these discs to separate from the sheet. The gray bar across the sheet is liquid being used to lift the discs from the surface

People think of graphene, an ultrathin but extremely strong material, as being “floppy,” but it is actually brittle, Strano explains. But rather than considering that brittleness a problem, the team figured out that it could be used to their advantage. “We discovered that you can use the brittleness,” says Strano, who is the Carbon P. Dubbs Professor of Chemical Engineering at MIT. “It’s counterintuitive. Before this work, if you told me you could fracture a material to control its shape at the nanoscale, I would have been incredulous.”

The novel process, called “autoperforation,” is described in a paper published today in the journal Nature Materials, by MIT Professor Michael Strano, postdoc Pingwei Liu, graduate student Albert Liu, and eight others at MIT.

Source: http://news.mit.edu/

The Rise Of The Hydrogen Electric Truck

Nikola Motor Company is welcoming everyone to Phoenix April 16-18, 2019 for a new blockbuster event, Nikola World. The first two days, April 16 and 17, are devoted to invite-only Nikola reservation holders, suppliers, media and investors while April 18 will be reserved for the public. On April 16, Nikola will unveil the pre-production hydrogen electric semi-truck, 2.3 megawatt hydrogen station and the Nikola NZT 4X4. April 17 will be dedicated to demonstration drives and hydrogen filling. On April 18, the public is invited to see the latest trucks and NZT in action.

Not only will our team be unveiling the most advanced production semi-truck the world has ever seen, but we will also be revealing the Nikola NZT all-electric 4×4 vehicle and a massive 2.3 megawatt hydrogen station. This is why we named it Nikola World – we want to create a better place to live where emissions are eliminated,” said Trevor Milton, CEO, Nikola Motor Company.

Nikola World registration will open on December 3, 2018 at www.nikolamotor.com. All the activities will be free. Milton added: “The largest fleets and customers in the world will attend this event and they will see what no other OEM could deliver – a production-ready, zero emission semi-truck, with over 1,000-mile range, 20 percent less operating costs per mile, more horsepower, torque and safety features than any other diesel ever built, and a startup did it. Remember that!

While diesel engines require high RPM’s to reach peak torque, the Nikola Two™ electric motors hit peak torque almost instantly.
Instant torque combined with all wheel drive give Nikola Two™ the ability to accelerate nearly 2x faster than a stock diesel tractor. There are several factors that give Nikola Two™ the advantage when it comes to fuel economy:

  • Better aerodynamics
  • Using energy only when needed (no idling)
  • Charging batteries via regenerative braking
  • 6X4 four-wheel drive – pulling and pushing at the same time
  • Up to 95% efficient electric motors
  • Up to 70% efficient fuel cell
  • When pulling at max capacity, every pound counts. With nearly 2,000 lbs of weight savings on the chassis, owners can throw more goods on each load.
    Every pound after max load may be worth as much as $.50. By saving up to 2,000 lbs, owners could earn approximately $1,000 in extra revenue from every load, every day. Owners that run at full load could see up to $30,000 or more each month in revenue straight to the bottom line.
  • Nikola‘s Complete Lease Program includes hydrogen fuel, warranty and scheduled maintenance. We get asked about the cost of ownership more than anything else. For this reason the Nikola™ Complete Leasing Program  has been created.
  • Nikola Motor Company wants to create the largest hydrogen network in the world that will cover over 2,000 miles and include 16 stations. Nikola has already kicked off two of the 16 stations and 14 more will follow immediately after installation.

Source: https://nikolamotor.com/

Creating Nanocages With Tunable Properties From DNA

How to create nanocages, i.e., robust and stable objects with regular voids and tunable properties? Short segments of DNA molecules are perfect candidates for the controllable design of novel complex structures. Physicists from the University of Vienna, the Technical University of Vienna, the Foschungszentrum Jülich in Germany and Cornell University in the U.S.A., investigated methodologies to synthesize DNA-based dendrimers in the lab and to predict their behavior using detailed computer simulations.

Nanocages are highly interesting molecular constructs, from the point of view of both fundamental science and possible applications. The cavities of these nanometer-sized objects can be employed as carriers of smaller molecules, which is of critical importance in medicine for drug or gene delivery in living organisms. This idea brought together researchers from various interdisciplinary fields who have been investigating dendrimers as promising candidates for creating such nano-carriers. Their tree-like architecture and step-wise growth with repeating self-similar units results in dendrimers containing cavities, hollow objects with controllable design.

The researchers found a way to create dendrimers rigid enough to prevent back-folding of outer arms even in the case of high branching generations, preserving regular voids in their interior. The nanocages they created, in the lab and studied computationally are DNA-based dendrimers, or so-called, dendrimer-like DNAs (DL-DNA).

Their results are published in the journal Nanoscale.

Source: https://medienportal.univie.ac.at/

Antibodies Are The New Cancer Weapon

Antibody-based imaging* of a particularly aggressive form of breast cancer is undergoing clinical trials worldwide, but the path from trial to application is being hampered by a major obstacle: safety. Concerns stem from inefficient tumor targeting, which can result in accumulation in the bone marrow, liver and kidneys of the radioactive material necessary for the imaging. Recent efforts have focused on nanoscale delivery vehicles with immune components, but these vehicles are often still too large (20 nanometers or larger) for renal clearance after imaging.

Ulrich Wiesner, the Spencer T. Olin Professor of Engineering in materials science and engineering, in collaboration with Dr. Michelle Bradbury of Memorial Sloan Kettering Cancer Center (MSKCC) and Weill Cornell Medicine, has proposed a novel approach using ultrasmall silica nanoparticles – better known as “Cornell dots” (or C dots) – invented in his lab more than a dozen years ago. Their team – including researchers at pharmaceutical company MedImmune – have equipped the C dots with antibody fragments. Because the resulting conjugates are smaller than 8 nanometers, these C dots allow for renal clearance while achieving the specificity needed for efficient tumor targeting.

They report their discovery in in Nature Communications. Feng Chen, senior research scientist at MSKCC, and Kai Ma, postdoctoral researcher in the Wiesner lab, are co-lead authors. Wiesner said this research creates “a whole new runway” to employ antibody fragments for a number of diseases, cancer in particular, and for diagnostics as well as drug delivery – when combined in a single entity also known as “theranostics.”

A rendering of the Cornell prime dot (left) with an attached antibody fragment (center) binding to a HER2 cancer cell receptor (right). The dot and antibody attachment combined are less than 8 nanometers in diameter, the limit for renal clearance.

This is the first time we’ve worked with these antibody fragments,” Wiesner said, “thereby harnessing the power of antibodies in the fight against cancer.”

Cancer imaging is an umbrella term that covers the many approaches used to research and diagnose cancer. Originally used to diagnose and stage the disease, cancer imaging is now also used to assist with surgery and radiotherapy, to look for early responses to cancer therapies and to identify patients who are not responding to treatment.

Source: http://news.cornell.edu/

New Material For New Processor

Computers used to take up entire rooms. Today, a two-pound laptop can slide effortlessly into a backpack. But that wouldn’t have been possible without the creation of new, smaller processors — which are only possible with the innovation of new materials. But how do materials scientists actually invent new materials? Through experimentation, explains Sanket Deshmukh, an assistant professor in the chemical engineering department of Virginia Tech whose team’s recently published computational research might vastly improve the efficiency and costs savings of the material design process.

Deshmukh’s lab, the Computational Design of Hybrid Materials lab, is devoted to understanding and simulating the ways molecules move and interact — crucial to creating a new material. In recent years, materials scientists have employed machine learning, a powerful subset of artificial intelligence, to accelerate the discovery of new materials through computer simulations. Deshmukh and his team have recently published research in the Journal of Physical Chemistry Letters demonstrating a novel machine learning framework that trainson the fly,” meaning it instantaneously processes data and learns from it to accelerate the development of computational models. Traditionally the development of computational models are “carried out manually via trial-and-error approach, which is very expensive and inefficient, and is a labor-intensive task,” Deshmukh explained.

This novel framework not only uses the machine learning in a unique fashion for the first time,” Deshmukh said, “but it also dramatically accelerates the development of accurate computational models of materials.” “We train the machine learning model in a ‘reverse’ fashion by using the properties of a model obtained from molecular dynamics simulations as an input for the machine learning model, and using the input parameters used in molecular dynamics simulations as an output for the machine learning model,” said Karteek Bejagam, a post-doctoral researcher in Deshmukh’s lab and one of the lead authors of the study.

This new framework allows researchers to perform optimization of computational models, at unusually faster speed, until they reach the desired properties of a new material.

Source: https://vtnews.vt.edu/

Perovskite Could Convert Up To 44% Of Light Into Electricity

Perovskites are a family of crystals that show promising properties for applications in nano-technology. However, one useful property that until now was unobserved in perovskites is so-called carrier multiplication – an effect that makes materials much more efficient in converting light into electricity. New research, led by University of Amsterdam (UvA-IoP) physicists Dr Chris de Weerd and Dr Leyre Gomez from the group of Prof. Tom Gregorkiewicz, has now shown that certain perovskites in fact do have this desirable propertyCrystals are configurations of atoms, molecules or ions, that are ordered in a structure that repeats itself in all directions. We have all encountered some crystals in everyday life: ordinary salt, diamond and even snowflakes are examples. What is perhaps less well-known is that certain crystals show very interesting properties when their size is not that of our everyday life but that of nanometers – a few billionths of a meter.

Perovskites – named after 19th century Russian mineralogist Lev Perovski – form a particular family of materials that all share the same crystal structure. These perovskites have many desirable electronic properties, making them useful for constructing for example LEDs, TV-screens, solar cells and lasers. A property which so far had not been shown to exist in perovskites is carrier multiplication. When semiconductors – in solar cells, for example – convert the energy of light into electricity, this is usually done one particle at a time: a single infalling photon results in a single excited electron (and the corresponding ‘hole’ where the electron used to be) that can carry an electrical current. However, in certain materials, if the infalling light is energetic enough, further electron-hole pairs can be excited as a result; it is this process that is known as carrier multiplication.

Until now, carrier multiplication had not been reported for perovskites. That we have now found it is of great fundamental impact on this upcoming material. For example, this shows that perovskite nanocrystals can be used to construct very efficient photodetectors, and in the future perhaps solar cells”, says De Weerd, who successfully defended her PhD thesis based on this and other research last week.

When carrier multiplication occurs, the conversion from light into electricity can become much more efficient. For example, in ordinary solar cells there is a theoretical limit (the so-called Shockley-Queisser limit) on the amount of energy that can be converted in this way: at most a little over 33% of the solar power gets turned into electrical power. In semiconductor nanocrystals that feature the carrier multiplication effect, however, a maximum efficiency of up to 44% is predicted.

The paper in which the researchers report on their findings was published in Nature Communications this week.

Source: http://iop.uva.nl/

How To Pilot A Drone Using Virtual Reality

Imagine piloting a drone using the movements of your torso only and leaving your head free to look around, much like a bird. The Ecole Polytechnique Fédérale de Lausanne  (EPFL) research, in Switzerland,  has just shown that using your torso to pilot flying machines is indeed more immersive – and more effective – than using the long-established joystick.

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Our aim was to design a control method which would be easy to learn and therefore require less mental focus from the users so that they can focus on more important issues, like search and rescue,” says lead author Jenifer Miehlbradt of EPFL’s Translational Neuroengineering Laboratory led by Bertarelli Foundation Chair Silvestro Micera. “Using your torso really gives you the feeling that you are actually flying. Joysticks, on the other hand, are of simple design but mastering their use to precisely control distant objects can be challenging.

The scientists wanted to observe how people use their bodies to pilot a flying object, in this case a drone, and determine which movements are most intuitive and natural – approaching the pilot problem from a completely new perspective.

They started by monitoring the body movements of 17 individuals thanks to 19 infrared markers placed all over the upper body as well as their muscular activity. Each participant followed the actions of a virtual drone through simulated landscapes that passed-by as viewed through virtual reality goggles.

The results are published in the journal PNAS.

Source: https://actu.epfl.ch/