Posts belonging to Category 3D printing



3-D Printed Graphene Foam

Nanotechnologists from Rice University and China’s Tianjin University have used 3-D laser printing to fabricate centimeter-sized objects of atomically thin graphene. The research could yield industrially useful quantities of bulk graphene and is described online in a new study in the American Chemical Society journal ACS Nano.

Laser sintering was used to 3-D print objects made of graphene foam, a 3-D version of atomically thin graphene. At left is a photo of a fingertip-sized cube of graphene foam; at right is a close-up of the material as seen with a scanning electron microscope

This study is a first of its kind,” said Rice chemist James Tour, co-corresponding author of the paper. “We have shown how to make 3-D graphene foams from nongraphene starting materials, and the method lends itself to being scaled to graphene foams for additive manufacturing applications with pore-size control.”

Graphene, one of the most intensely studied nanomaterials of the decade, is a two-dimensional sheet of pure carbon that is both ultrastrong and conductive. Scientists hope to use graphene for everything from nanoelectronics and aircraft de-icers to batteries and bone implants. But most industrial applications would require bulk quantities of graphene in a three-dimensional form, and scientists have struggled to find simple ways of creating bulk 3-D graphene.

For example, researchers in Tour’s lab began using lasers, powdered sugar and nickel to make 3-D graphene foam in late 2016. Earlier this year they showed that they could reinforce the foam with carbon nanotubes, which produced a material they dubbed “rebar graphene” that could retain its shape while supporting 3,000 times its own weight. But making rebar graphene was no simple task. It required a pre-fabricated 3-D mold, a 1,000-degree Celsius chemical vapor deposition (CVD) process and nearly three hours of heating and cooling.  “This simple and efficient method does away with the need for both cold-press molds and high-temperature CVD treatment,” said co-lead author Junwei Sha, a former student in Tour’s lab who is now a postdoctoral researcher at Tianjin. “We should also be able to use this process to produce specific types of graphene foam like 3-D printed rebar graphene as well as both nitrogen- and sulfur-doped graphene foam by changing the precursor powders.” Sha and colleagues conducted an exhaustive study to find the optimal amount of time and laser power to maximize graphene production. The foam created by the process is a low-density, 3-D form of graphene with large pores that account for more than 99 percent of its volume.

The 3-D graphene foams prepared by our method show promise for applications that require rapid prototyping and manufacturing of 3-D carbon materials, including energy storage, damping and sound absorption,” said co-lead author Yilun Li, a graduate student at Rice.

Source: http://news.rice.edu/

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/

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.

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“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/
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http://www.reuters.com/

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‘.

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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/

3D Printing Art And Design in Paris

Do you plan  to travel to Paris? In this case do not miss to visit the Centre Pompidou,  this huge museum, located in the center of Paris and dedicated to modern Art.  You can assist to  “Mutations/Créations“: a new event decidedly turned towards the future and the interaction between digital technology and creation; a territory shared by art, innovation and science.

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Drawing on all the disciplines in a mix of research, art and engineering, the first edition of this annual event calls upon music, design and architecture. It consists of two exhibitions (“Imprimer le monde“ and “Ross Lovegrove“), an Art/Innovation Forum entitled “Vertigo“, and various study days and get-togethers. Each year, thematic and monographic exhibitions will be staged around meetings and workshops that turn the Centre Pompidou into an “incubator“: a place for demonstrating prototypes, carrying out artistic experiments in vivo, and talking with designers. This platform will also be a critical observatory and a tool for analysing the impact of creation on society. How have the various forms of creation begun using digital technologies to open up new industrial perspectives? How do they question the social, economic and political effects of these industrial developments, and their ethical limits? What formal transformations have come about in music, art, design and architecture with regard to technical and scientific progress?


In the same space,  you can see a  new retrospective devoted to British designer Ross Lovegrove, which shows how the artist has introduced a fresh dialogue between nature and technology, where art and science converge. He employs a “holistic“ idea of design through a visionary practice that began incorporating digital changes during the 1990s, rejecting the productivism of mass industry and replacing it with a more economical approach to materials and forms. This exhibition emphasises the role of design in the postindustrial era, now that we are seeing a significant shift from mechanics to organics: a changeover symptomatic of our times, which these “digital forms“ endeavour to highlight.

Source: https://www.centrepompidou.fr/

College Student 3D Prints His Own Braces

Amos Dudley wears his skills in his smile. The digital design major has been straightening his top teeth for the past 16 weeks using clear braces he made himself.

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 “I’m still wearing the last one,” said Dudley . “The last one” refers to the twelfth and final straightening tray in his self-designed treatment. Dudley said he had braces when he was in junior high, but he didn’t wear his retainer as much as he should have, and his teeth shifted. Over time, Dudley discovered that he wasn’t smiling as much because he wasn’t happy with the way his teeth looked.

Name brand options for clear braces can cost up to $8,000, according to companies like Invisalign, Damon, and ClearCorrect. But the 24-year-old wanted to save money, so he found a way to manufacture his own for less than $60. The total cost is so low because he only had to pay for materials used to make the models of his teeth and the retainers. Even though he built his own 3D printer at home, he opted to use a high-end and more precise 3D printer at his school, New Jersey Institute of Technology.

He used NJIT’s equipment to scan and print models of his teeth, and mold non-toxic plastic around them to form the set of 12 clear braces. Dudley determined out how far he needed to move his teeth to correct the misalignment problems. Then divided it by the maximum recommended distance a tooth should travel to determine the design for each alignment tray. Orthodontists use a similar process. Researching the materials he needed and figuring out how teeth move was the most difficult part of Dudley’s orthodontic adventure. The most exciting was when he finally put the first aligner in his mouth. “It was very obvious which tooth [the tray] was putting pressure on,” he said. “I was sort of worried about accumulated error, but that wasn’t the case so that was a pretty glorious moment.

Source: http://money.cnn.com/

Dissolvable Metal Supports for 3D Printing

Support for a visiting professor plus an off-the-cuff remark have led an Arizona State University (ASU) researcher to develop what could be the Holy Grail solution to speeding up the end-to-end process of metal 3D printing.

Owen Hildreth, ASU assistant professor of 3D Nanofabrication, was developing new approaches to reactive silver ink production when he thought he’d sit in on talks regarding the soon-to-be-opened ASU Polytechnic Manufacturing Research and Innovation Hub. One of the speakers, Timothy Simpson, was describing the practical challenges of setting up an additive manufacturing (AM) lab.

Combining a mechanical engineering degree (applied to five years’ work in the 2D printing industry) with a Ph.D. in nanofabrication materials engineering, Hildreth just may have been in the perfect position to bring a fresh perspective to the metal support problem. In contrast to the use of mechanical tools such as wire-EDM equipment, his concept would cause certain areas of a metal AM part to react chemically when immersed in a corrosive solution. The goal was to produce controlled degradation that would literally eat away the supports but leave the actual part virtually intact.

However, because multi-material 3D printing systems are not yet widely available, Hildreth also investigated ways to selectively remove the supports of powder-bed-type metal AM parts. Starting with a simple design for demonstration — a small 17-4 stainless steel cylinder 3D-printed with a single row of 100-micron-diameter needle-like supports — he tested two possible approaches.

In the first one, termed direct dissolution, the part was heat-treated (annealed) while packed with sodium ferrocyanide; this step precipitated out much of the protective chromium carbide, rendering the no-longer-stainless steel susceptible to chemical etching. The latter process was successful, but the part itself experienced significant etching, which continued the longer the part was allowed to sit in the solution.

Source: http://www.rapidreadytech.com/

Inkjet Printers Grow Nerve Stem Cells

Inkjet printers and lasers are parts of a new way to produce cells important to research on nerve regeneration. Researchers at Iowa State University have developed a nanotechnology that uses inkjet printers to print multi-layer graphene circuits….It turns out mesenchymal stem cells adhere and grow well on the treated circuit’s raised, rough, and 3D nanostructures. Add small doses of electricity—100 millivolts for 10 minutes per day over 15 days—and the stem cells become Schwann-like cells, [which secrete substances that promote the health of nerve cells].

nerve cells

This technology could lead to a better way to differentiate stem cells,” says Metin Uz, a postdoctoral research associate in chemical and biological engineering. The researchers report the results could lead to changes in how nerve injuries are treated inside the body. “These results help pave the way for in vivo peripheral nerve regeneration where the flexible graphene electrodes could conform to the injury site and provide intimate electrical stimulation for nerve cell regrowth,” the researchers write in a summary of their findings.

Source: https://www.geneticliteracyproject.org/

Spintronics

A team of scientists led by Associate Professor Yang Hyunsoo from the National University of Singapore’s (NUS) Faculty of Engineering has invented a novel ultra-thin multilayer film which could harness the properties of tiny magnetic whirls, known as skyrmions, as information carriers for storing and processing data (nanocomputer) on magnetic media. The nano-sized thin film, which was developed in collaboration with researchers from Brookhaven National Laboratory, Stony Brook University, and Louisiana State University, is a critical step towards the design of data storage devices that use less power and work faster than existing memory technologies.

The digital transformation has resulted in ever-increasing demands for better processing and storing of large amounts of data, as well as improvements in hard drive technology. Since their discovery in magnetic materials in 2009, skyrmions, which are tiny swirling magnetic textures only a few nanometres in size, have been extensively studied as possible information carriers in next-generation data storage and logic devices.

Skyrmions have been shown to exist in layered systems, with a heavy metal placed beneath a ferromagnetic material. Due to the interaction between the different materials, an interfacial symmetry breaking interaction, known as the Dzyaloshinskii-Moriya interaction (DMI), is formed, and this helps to stabilise a skyrmion. However, without an out-of-plane magnetic field present, the stability of the skyrmion is compromised. In addition, due to its tiny size, it is difficult to image the nano-sized materials. The NUS team found that a large DMI could be maintained in multilayer films composed of cobalt and palladium, and this is large enough to stabilise skyrmion spin textures.

skyrmionsThis experiment not only demonstrates the usefulness of L-TEM in studying these systems, but also opens up a completely new material in which skyrmions can be created. Without the need for a biasing field, the design and implementation of skyrmion based devices are significantly simplified. The small size of the skyrmions, combined with the incredible stability generated here, could be potentially useful for the design of next-generation spintronic devices that are energy efficient and can outperform current memory technologies,” explains Professor Yang .

The invention was reported in the journal Nature Communications.

Source: http://news.nus.edu.sg

Ultrafast Flexible Electronic Memory

Engineering experts from the University of Exeter (UK) have developed innovative new memory using a hybrid of graphene oxide and titanium oxide. Their devices are low cost and eco-friendly to produce, are also perfectly suited for use in flexible electronic devices such as ‘bendablemobile phone, computer and television screens, and even ‘intelligentclothing.
. Crucially, these devices may also have the potential to offer a cheaper and more adaptable alternative to ‘flash memory’, which is currently used in many common devices such as memory cards, graphics cards and USB computer drives. The research team insist that these innovative new devices have the potential to revolutionise not only how data is stored, but also take flexible electronics to a new age in terms of speed, efficiency and power.

bendable mobile phone

Using graphene oxide to produce memory devices has been reported before, but they were typically very large, slow, and aimed at the ‘cheap and cheerful’ end of the electronics goods market”, said Professor David Wright, an Electronic Engineering expert from the University of Exeter.

Our hybrid graphene oxide-titanium oxide memory is, in contrast, just 50 nanometres long and 8 nanometres thick and can be written to and read from in less than five nanoseconds – with one nanometre being one billionth of a metre and one nanosecond a billionth of a second.”

The research is published in the scientific journal ACS Nano.

Source: http://www.exeter.ac.uk/

Graphene And Fractals Boost The Solar Power Storage By 3000%

Inspired by an American fern, researchers have developed a groundbreaking prototype that could be the answer to the storage challenge still holding solar back as a total energy solution. The new type of electrode created by RMIT University (Australia) researchers could boost the capacity of existing integrable storage technologies by 3000 per cent. But the graphene-based prototype also opens a new path to the development of flexible thin film all-in-one solar capture and storage, bringing us one step closer to self-powering smart phones, laptops, cars and buildings. The new electrode is designed to work with supercapacitors, which can charge and discharge power much faster than conventional batteries. Supercapacitors have been combined with solar, but their wider use as a storage solution is restricted because of their limited capacity.

RMIT’s Professor Min Gu said the new design drew on nature’s own genius solution to the challenge of filling a space in the most efficient way possible – through intricate self-repeating patterns known as “fractals”.

The leaves of the western swordfern are densely crammed with veins, making them extremely efficient for storing energy and transporting water around the plant,” said Gu, Leader of the Laboratory of Artificial Intelligence Nanophotonics at RMIT.

mimicking fern

Our electrode is based on these fractal shapes – which are self-replicating, like the mini structures within snowflakes – and we’ve used this naturally-efficient design to improve solar energy storage at a nano level. “The immediate application is combining this electrode with supercapacitors, as our experiments have shown our prototype can radically increase their storage capacity30 times more than current capacity limits.   “Capacity-boosted supercapacitors would offer both long-term reliability and quick-burst energy release – for when someone wants to use solar energy on a cloudy day for example – making them ideal alternatives for solar power storage.”  Combined with supercapacitors, the fractal-enabled laser-reduced graphene electrodes can hold the stored charge for longer, with minimal leakage.

Source: https://www.rmit.edu.au/

Smart Printed Electronics

Researchers in AMBER, the materials science research centre hosted in Trinity College Dublin, have fabricated printed transistors consisting entirely of 2-dimensional nanomaterials for the first time. These 2D materials combine exciting electronic properties with the potential for low-cost production. This breakthrough could unlock the potential for applications such as food packaging that displays a digital countdown to warn you of spoiling, wine labels that alert you when your white wine is at its optimum temperature, or even a window pane that shows the day’s forecast

This discovery opens the path for industry, such as ICT and pharmaceutical, to cheaply print a host of electronic devices from solar cells to LEDs with applications from interactive smart food and drug labels to next-generation banknote security and e-passports.

printed transistor

Prof Jonathan Coleman, who is an investigator in AMBER and Trinity’s School of Physics, said, “In the future, printed devices will be incorporated into even the most mundane objects such as labels, posters and packaging.
Printed electronic circuitry (constructed from the devices we have created) will allow consumer products to gather, process, display and transmit information: for example, milk cartons could send messages to your phone warning that the milk is about to go out-of-date.

We believe that 2D nanomaterials can compete with the materials currently used for printed electronics. Compared to other materials employed in this field, our 2D nanomaterials have the capability to yield more cost effective and higher performance printed devices. However, while the last decade has underlined the potential of 2D materials for a range of electronic applications, only the first steps have been taken to demonstrate their worth in printed electronics. This publication is important because it shows that conducting, semiconducting and insulating 2D nanomaterials can be combined together in complex devices. We felt that it was critically important to focus on printing transistors as they are the electric switches at the heart of modern computing. We believe this work opens the way to print a whole host of devices solely from 2D nanosheets.”
Led by Prof Coleman, in collaboration with the groups of Prof Georg Duesberg (AMBER) and Prof. Laurens Siebbeles (TU Delft, Netherlands), the team used standard printing techniques to combine graphene nanosheets as the electrodes with two other nanomaterials, tungsten diselenide and boron nitride as the channel and separator (two important parts of a transistor) to form an all-printed, all-nanosheet, working transistor.

The AMBER team’s findings have been published today in the journal Science*.

Source: http://ambercentre.ie