Posts belonging to Category Materials



Cellulose-based Ink For 3D Printing

Empa (Switzerland) researchers have succeeded in developing an environmentally friendly ink for 3D printing based on cellulose nanocrystals. This technology can be used to fabricate microstructures with outstanding mechanical properties, which have promising potential uses in implants and other biomedical applications.

Cellulose, along with lignin and hemicellulose, is one of the main constituents of wood. The biopolymer consists of glucose chains organized in long fibrous structures. In some places the cellulose fibrils exhibit a more ordered structure.

In order to produce 3D microstructured materials for composite applications, for instance, Empa researchers have been using a 3D printing method called “Direct Ink Writing” for the past year. During this process, a viscous substance – the printing ink – is squeezed out of the printing nozzles and deposited onto a surface, pretty much like a pasta machine. Empa researchers Gilberto Siqueira and Tanja Zimmermann from the Laboratory for Applied Wood Materials have now succeeded, together with Jennifer Lewis from Harvard University and André Studart from the ETH Zürich, in developing a new, environmentally friendly 3D printing ink made from cellulose nanocrystals (CNC).
The places with a higher degree of order appear in a more crystalline form. And it is these sections, which we can purify with acid, that we require for our research“, explains Siqueira. The final product is cellulose nanocrystals, tiny rod-like structures that are 120 nanometers long and have a diameter of 6.5 nanometers. And it is these nanocrystals that researchers wanted to use to create a new type of environmentally friendly 3D printing ink.They have now succeeded that  their new inks contain a full 20 percent CNC.

The biggest challenge was in attaining a viscous elastic consistency that could also be squeezed through the 3D printer nozzles“, says Siqueira. The ink must be “thick” enough so that the printed material stays “in shape” before drying or hardening, and doesn’t immediately melt out of shape again.

Source: https://www.empa.ch/

How Yo Make Sea Water Drinkable

Graphene-oxide membranes have attracted considerable attention as promising candidates for new filtration technologies. Now the much sought-after development of making membranes capable of sieving common salts has been achieved. New research demonstrates the real-world potential of providing clean drinking water for millions of people who struggle to access adequate clean water sources. Graphene-oxide membranes developed at the National Graphene Institute have already demonstrated the potential of filtering out small nanoparticles, organic molecules, and even large salts. Until now, however, they couldn’t be used for sieving common salts used in desalination technologies, which require even smaller sieves. Previous research at The University of Manchester found that if immersed in water, graphene-oxide membranes become slightly swollen and smaller salts flow through the membrane along with water, but larger ions or molecules are blocked.

The Manchester-based group have now further developed these graphene membranes and found a strategy to avoid the swelling of the membrane when exposed to water. The pore size in the membrane can be precisely controlled which can sieve common salts out of salty water and make it safe to drink.

CLICK ON THE IMAGE TO ENJOY THE VIDEO

Realisation of scalable membranes with uniform pore size down to atomic scale is a significant step forward and will open new possibilities for improving the efficiency of desalination technology,” says Professor Rahul Raveendran Nair.

The new findings from a group of scientists at The University of Manchester have been published in the journal Nature Nanotechnology.

Source: http://www.manchester.ac.uk/
AND
http://www.reuters.com/

Metal 3D Printing Withstands Extreme Pressure And Heat

3D printed metal turbine blades able to withstand extreme pressure have been successfully tested by Siemens. It opens the way to develop high pressure components for power generators and other industries, such as aeronautics. These blades can survive temperatures above 1,250 Celsius and pressures similar to the weight of a double-decker bus.

 CLICK ON THE IMAGE TO ENJOY THE VIDEO

“To have this rotating part running is a breakthrough because it is submitted to these extreme loading… It rotates with 13,600 rotations-per-minute which means it is the most highly loaded component in the whole gas turbine. So this blade that weighs 180 grams will weigh 11 tonnes while rotating with this speed,” says Jenny Nilsson, Team leader for additive manufacturing at Siemens.

Last year Siemens bought British-based Material Solutions, where the metal-based printing is being perfected. A computer-aided design model is first sent to one of these machines. Precision lasers are then fired at a thin layer of metal powder.

This is the nickel superalloy powder. This metallic powder is deposited in 20 micron layer thickness and then the laser melts the part,“explains Clotilde Ravoux, system engineer at Material Solutions.

Ultra-thin layers are added one by one, building up the part. Testing is ongoing and Siemens can’t say when these blades will be commercially produced. But they say it reduces the design-to-testing time from years to months.  “When you apply casting procedures you will probably take one to one and a half years to provide you with these blades because of their long lead-time for tooling. And by applying additive manufacturing we could significantly shorten lead time by down to three months,” adds  Christoph Haberland, manufacturing engineering.

General Electric introduced its first 3D-printed aircraft engine component into service last July. While Boeing is using metal-based 3D printing to drastically cut the production costs of its 787 Dreamliner.

Source: https://www.siemens.com/
AND
http://www.reuters.com/

Powerful Anti-Aging Cream Using Nanotechnology

Wrinkle-smoothing hyaluronic acid can now be introduced into the skin without injections, thanks to an Israeli research team that spent years developing a nanotechnology for this purpose. Facial wrinkles, lines and sagging result from the body’s gradual loss of its ability to produce hyaluronic acid. In the past, treatments of hyaluronic acid couldn’t get into the skin’s deepest layers except by injection or in a powder form that must be mixed with water and therefore loses its potency.

That problem was solved by a research team headed by Prof. Rachel Lubart and Prof. Aharon Gedanken from the departments of chemistry and physics and Bar-Ilan University’s Institute for Nanotechnology and Advanced Materials (BINA). The Israeli scientists achieved this breakthrough by micronizingbreaking down its particles to the size of a micronhyaluronic acid. Based on this development, Israeli cosmetic pharmaceuticals pioneer Hava Zingboim has created Prophecy, the first-ever cream formula that allows hyaluronic acid to penetrate into the deeper skin layers.

Once they reach nano size, the hyaluronic acid molecules are transferred into the formula, which enables them to remain nano-sized throughout the process. The effect of the micronized hyaluronic acid applied to the skin is identical to the effect achieved when injecting hyaluronic acid into the skin, with the benefits of enhanced skin texture and a younger look.
According to a university statement, this is the only technology in the world capable of creating small molecules that remain small even when applied to the skin.

Source: https://www.israel21c.org/
A
ND
http://reshet.tv/

Startup Promises Immortality Through AI, Nanotechnology, and Cloning

One of the things humans have plotted for centuries is escaping death, with little to show for it, until now. One startup called Humai has a plan to make immortality a reality. The CEO, Josh Bocanegra says when the time comes and all the necessary advancements are in place, we’ll be able to freeze your brain, create a new, artificial body, repair any damage to your brain, and transfer it into your new body. This process could then be repeated in perpetuityHUMAI stands for: Human Resurrection through Artificial Intelligence. The technology to accomplish this isn’t here now, but on the horizon. Bocanegra says they’ll reach this Promethean feat within 30 years. 2045 is currently their target date. So how do they plan to do it?

We’re using artificial intelligence and nanotechnology to store data of conversational styles, behavioral patterns, thought processes and information about how your body functions from the inside-out. This data will be coded into multiple sensor technologies, which will be built into an artificial body with the brain of a deceased human, explains the website.

Source: https://www.facebook.com/humaitech/
AND
http://bigthink.com/

Legally Blind People Can See With A New Kind Of Glasses

A Canadian company based in Toronto has suceeded to build a kind of Google glass that is able to give back full sight to legally blind people.  The eSight is an augmented reality headset that houses a high-speed, high-definition camera that captures everything the user is looking at.

CLICK ON THE IMAGE TO ENJOY THE VIDEO


Algorithms enhance the video feed and display it on two, OLED screens in front of the user’s eyes. Full color video images are clearly seen by the eSight user with unprecedented visual clarity and virtually no lag. With eSight’s patented Bioptic Tilt capability, users can adjust the device to the precise position that, for them, presents the best view of the video while maximizing side peripheral vision. This ensures a user’s balance and prevents nausea – common problems with other immersive technologies. A blind individual can use both of their hands while they use eSight to see. It is lightweight, worn comfortably around the eyes and designed for various environments and for use throughout the day.

eSight is a comprehensive customized medical device that can replace all the many single-task assistive devices that are currently available but do not provide actual sight (e.g. white canes, magnifying devices, service animals, Braille machines, CCTV scanners, text-to-speech software). It allows a user to instantly auto-focus between short-range vision (reading a book or text on a smartphone) to mid-range vision (seeing faces or watching TV) to long-range vision (looking down a hallway or outsidea window). It is the only device for the legally blind that enables mobility without causing issues of imbalance or nausea (common with other immersive options). A legally blind individual can use eSight not just to see while sitting down but while being independently mobile (e.g. walking, exercising, commuting, travelling, etc).

According to The Wall Street Journal, the company is taking advantages of recent improvements in technology from VR headsets and smartphones that have trickled down to improve the latest version of the eSight. So far, the company has sold roughly a thousand units, but at $10,000 apiece, they’re not cheap (and most insurances apparently don’t cover the product), although eSight’s chief executive Brian Mech notes to the WSJ that getting devices to users is “a battle we are starting to wage.”

Source: https://www.esighteyewear.com/

Rechargeable Lithium Metal Battery

Rice University scientists have created a rechargeable lithium metal battery with three times the capacity of commercial lithium-ion batteries by resolving something that has long stumped researchers: the dendrite problem.

The Rice battery stores lithium in a unique anode, a seamless hybrid of graphene and carbon nanotubes. The material first created at Rice in 2012 is essentially a three-dimensional carbon surface that provides abundant area for lithium to inhabit. Lithium metal coats the hybrid graphene and carbon nanotube anode in a battery created at Rice University. The lithium metal coats the three-dimensional structure of the anode and avoids forming dendrites.

The anode itself approaches the theoretical maximum for storage of lithium metal while resisting the formation of damaging dendrites or “mossy” deposits.

Dendrites have bedeviled attempts to replace lithium-ion with advanced lithium metal batteries that last longer and charge faster. Dendrites are lithium deposits that grow into the battery’s electrolyte. If they bridge the anode and cathode and create a short circuit, the battery may fail, catch fire or even explode.

Rice researchers led by chemist James Tour found that when the new batteries are charged, lithium metal evenly coats the highly conductive carbon hybrid in which nanotubes are covalently bonded to the graphene surface. As reported in the American Chemical Society journal ACS Nano, the hybrid replaces graphite anodes in common lithium-ion batteries that trade capacity for safety.

Lithium-ion batteries have changed the world, no doubt,” Tour said, “but they’re about as good as they’re going to get. Your cellphone’s battery won’t last any longer until new technology comes along.

He said the new anode’s nanotube forest, with its low density and high surface area, has plenty of space for lithium particles to slip in and out as the battery charges and discharges. The lithium is evenly distributed, spreading out the current carried by ions in the electrolyte and suppressing the growth of dendrites.

Source: http://news.rice.edu

Super-Efficient Production Of Hydrogen From Solar Energy

Hydrogen is an alternative source of energy that can be produced from renewable sources of sunlight and water. A group of Japanese researchers has developed a photocatalyst that increases hydrogen production tenfold.

When light is applied to photocatalysts, electrons and holes are produced on the surface of the catalyst, and hydrogen is obtained when these electrons reduce the hydrogen ions in water. However, in traditional photocatalysts the holes that are produced at the same time as the electrons mostly recombine on the surface of the catalyst and disappear, making it difficult to increase conversion efficiency.

Professor Tachikawa’s research group from the Kobe University developed a photocatalyst made of mesocrystal, deliberately creating a lack of uniformity in size and arrangement of the crystals. This new photocatalyst is able to spatially separate the electrons and electron holes to prevent them recombining. As a result, it has a far more efficient conversion rate for producing hydrogen than conventional nanoparticulate photocatalysts (approximately 7%).

The team developed a new method called “Topotactic Epitaxial Growth” that uses the nanometer-sized spaces in mesocrystals.
Using these findings, the research group plans to apply mesocrystal technology to realizing the super-efficient production of hydrogen from solar energy. The perovskite metal oxides, including strontium titanate, the target of this study, are the fundamental materials of electronic elements, so their results could be applied to a wide range of fields.

The discovery was made by a joint research team led by Associate Professor Tachikawa Takashi (Molecular Photoscience Research Center, Kobe University) and Professor Majima Tetsuro (Institute of Scientific and Industrial Research, Osaka University). Their findings were published  in the online version of Angewandte Chemie International Edition.

Source: http://www.kobe-u.ac.jp/

Asthma: Graphene-Based Sensor Improves Treatment

Scientists from Rutgers University have created a graphene-based sensor that could lead to earlier detection of looming asthma attacks and improve the management of asthma and other respiratory diseases, preventing hospitalizations and deaths.

The sensor paves the way for the development of devices – possibly resembling fitness trackers like the Fitbit – which people could wear and then know when and at what dosage to take their medication.


Exhaled breath condensate (tiny droplets of liquid) are rapidly analyzed by a graphene-based nanoelectronic sensor that detects nitrite, a key inflammatory marker in the inner lining of the respiratory airway.

Our vision is to develop a device that someone with asthma or another respiratory disease can wear around their neck or on their wrist and blow into it periodically to predict the onset of an asthma attack or other problems,” said Mehdi Javanmard, an assistant professor in the Department of Electrical and Computer Engineering. “It advances the field of personalized and precision medicine.

Javanmard and a diverse team of RutgersNew Brunswick experts describe their invention in a study published online today in the journal Microsystems & Nanoengineering.

Asthma, which causes inflammation of the airway and obstructs air flow, affects about 300 million people worldwide. About 17.7 million adults and 6.3 million children in the United States were diagnosed with asthma in 2014. Symptoms include coughing, wheezing, shortness of breath, and chest tightness. Other serious lung ailments include chronic obstructive pulmonary disease (COPD), which encompasses emphysema and chronic bronchitis.

Measuring biomarkers in exhaled breath condensatetiny liquid droplets discharged during breathing – can contribute to understanding asthma at the molecular level and lead to targeted treatment and better disease management. The Rutgers researchers’ miniaturized electrochemical sensor accurately measures nitrite in exhaled breath condensate using reduced graphene oxide. Reduced graphene oxide resists corrosion, has superior electrical properties and is very accurate in detecting biomarkers.

Source: http://news.rutgers.edu/

Self-Healing Lithium-Ion Batteries

Researchers at the University of Illinois have found a way to apply self-healing technology to lithium-ion batteries to make them more reliable and last longer.

The group developed a battery that uses a silicon nanoparticle composite material on the negatively charged side of the battery and a novel way to hold the composite together – a known problem with batteries that contain silicon.

Materials science and engineering professor Nancy Sottos and aerospace engineering professor Scott White led the study published in the journal Advanced Energy Materials.

“This work is particularly new to self-healing materials research because it is applied to materials that store energy,” White said. “It’s a different type of objective altogether. Instead of recovering structural performance, we’re healing the ability to store energy.”

The negatively charged electrode, or anode, inside the lithium-ion batteries that power our portable devices and electric cars are typically made of a graphite particle composite. These batteries work well, but it takes a long time for them to power up, and over time, the charge does not last as long as it did when the batteries were new.

Silicon has such a high capacity, and with that high capacity, you get more energy out of your battery, except it also undergoes a huge volume expansion as it cycles and self-pulverizes,” Sottos explained.

Past research found that battery anodes made from nanosized silicon particles are less likely to break down, but suffer from other problems.

You go through the charge-discharge cycle once, twice, three times, and eventually you lose capacity because the silicon particles start to break away from the binder,” White said.

To combat this problem, the group further refined the silicon anode by giving it the ability to fix itself on the fly. This self-healing happens through a reversible chemical bond at the interface between the silicon nanoparticles and polymer binder.

Source: https://news.illinois.edu/

The Rise Of The Cyborg

Researchers from UCLA and the University of Connecticut have designed a new biofriendly energy storage system called a biological supercapacitor, which operates using charged particles, or ions, from fluids in the human body. The device is harmless to the body’s biological systems, and it could lead to longer-lasting cardiac pacemakers and other implantable medical devices like artificial heart.

The UCLA team was led by Richard Kaner, a distinguished professor of chemistry and biochemistry, and of materials science and engineering, and the Connecticut researchers were led by James Rusling, a professor of chemistry and cell biology. A paper about their design was published this week in the journal Advanced Energy Materials.

Pacemakers — which help regulate abnormal heart rhythms — and other implantable devices have saved countless lives. But they’re powered by traditional batteries that eventually run out of power and must be replaced, meaning another painful surgery and the accompanying risk of infection. In addition, batteries contain toxic materials that could endanger the patient if they leak.

The researchers propose storing energy in those devices without a battery. The supercapacitor they invented charges using electrolytes from biological fluids like blood serum and urine, and it would work with another device called an energy harvester, which converts heat and motion from the human body into electricity — in much the same way that self-winding watches are powered by the wearer’s body movements. That electricity is then captured by the supercapacitor.

Combining energy harvesters with supercapacitors can provide endless power for lifelong implantable devices that may never need to be replaced,” said Maher El-Kady, a UCLA postdoctoral researcher and a co-author of the study.

Source: http://newsroom.ucla.edu/

Super-material Bends, Shapes And Focuses Sound Waves

These tiny 3D-printed bricks could one day allow people to create their own acoustics. That’s the plan of scientists from the universities of Bristol and Sussex. They’ve invented a metamaterial which bends and manipulates sound in any way the user wants. It’s helped scientists create what they call a ‘sonic alphabet‘.

CLICK ON THE IMAGE TO ENJOY THE VIDEO

We have discovered that you just need 16 bricks to make any type of sound that you can imagine. You can shape the sound just with 16 of them, just like you create any words with just 26 letters,” says Dr. Gianluca Memoli, researcher at Interact Lab at University of Sussex.

DIY kits like this, full of batches of the 16 aural letters, could help users create a sound library, or even help people in the same car to hear separate things.

With our device what you can have is you can strap a static piece on top of existing speakers and they can direct sound in two different directions without any overlap. So the passengers can hear completely different information from the driver,” explains Professor Sri Subramanian Interact Lab at University of Sussex. This technology is more than five years away, but smaller versions could be used to direct medical ultrasound devices far sooner.  “In a year we could have a sleeve that we can put on top of already existing projects in the market and make them just a little bit better. For example, we can have a sleeve that goes on top of ultrasound pain relieving devices that are used for therapeutic pain,” he adds.
Researchers say spatial sound modulators will one day allow us to perform audible tasks previously unheard of.

Source: http://www.sussex.ac.uk/