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/

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/

How To Build A 3D Printed House in One Day For $10,000

San Francisco-based Apis Cor reported on its blog that on a cold day last December it (and a number of its partners) built an entire 400 square foot house with its custom printer and it only cost $10,000. Oh, and it took just 24 hours to complete.

ApisCor_febr_top

Others have claimed to build houses with 3D printers. But what makes Apis Cor’s house unique is that it wasn’t constructed from pre-printed panels that required assembly by construction workers. The “printer” used is a giant, mobile piece of crane-like equipment that layers on cement in one continuous process, building both the internal and external structure all at once instead of in multiple parts. It’s a one-story structure but it can be constructed in just about any shape and the company showed how it could be built in even the coldest of conditions in this YouTube video.

Contractors worrying about their jobs shouldn’t panic…yet. Once all the walls are put together, those workers are then needed to do everything else – like installing windows and the roof, plus painting, insulating and putting in appliances, according to this report in Quartz. A finished test house that the company built with a partner in Russia is “cozy and comfortable” and includes “a hall, a bathroom, a living room and a compact functional kitchen with the most modern appliances from Samsung company,” Apis Cor’s blog boasts.

3D printed house

As you can see with the advent of new technology,” the company says in its blog post. “Construction 3D printing is changing the view and approach to the construction of low-rise buildings and provides new opportunities to implement custom architectural solutions.

The possibilities of this advancement in 3D printing are many. Houses could be quickly constructed for refugee camps, people displaced by natural disaster or for those who do not have available housing, such as the homeless. Governments could build entire communities of affordable housing at just a fraction of what’s paid today.

Source:  https://www.washingtonpost.com/
AND
http://apis-cor.com/

Printable solar cells

A University of Toronto (U of T) Engineering innovation could make building printing cells as easy and inexpensive as printing a newspaper. Dr. Hairen Tan and his team have cleared a critical manufacturing hurdle in the development of a relatively new class of solar devices called perovskite solar cells. This alternative solar technology could lead to low-cost, printable solar panels capable of turning nearly any surface into a power generator.

Printable Perovskite SolarCell

Economies of scale have greatly reduced the cost of silicon manufacturing,” says University Professor Ted Sargent (ECE), an expert in emerging solar technologies and the Canada Research Chair in Nanotechnology and senior author on the paper. “Perovskite solar cells can enable us to use techniques already established in the printing industry to produce solar cells at very low cost. Potentially, perovskites and silicon cells can be married to improve efficiency further, but only with advances in low-temperature processes.”

Today, virtually all commercial solar cells are made from thin slices of crystalline silicon which must be processed to a very high purity. It’s an energy-intensive process, requiring temperatures higher than 1,000 degrees Celsius and large amounts of hazardous solvents.

In contrast, perovskite solar cells depend on a layer of tiny crystals — each about 1,000 times smaller than the width of a human hair — made of low-cost, light-sensitive materials. Because the perovskite raw materials can be mixed into a liquid to form a kind of ‘solar ink’, they could be printed onto glass, plastic or other materials using a simple inkjet process.

Source: http://news.engineering.utoronto.ca

3D Printing and Nanotechnology To Detect Toxic Liquids

Carbon nanotubes have made headlines in scientific journals for a long time, as has 3D printing. But when both combine with the right polymer, in this case a thermoplastic, something special occurs: electrical conductivity increases and makes it possible to monitor liquids in real time. This is a breakthrough for Polytechnique Montréal.

In practical terms, the result of this research, led by  Professor Daniel Therriault, looks like a cloth; but as soon as a liquid comes into contact with it, said cloth is able to identify its nature. In this case, it is ethanol, but it might have been another liquid. Such a process would be a terrific advantage to heavy industry, which uses countless toxic liquids.

carbon nanotubes

While deceptively simple, the recipe is so efficient that Professor Therriault protected it with a patent. In fact, a U.S. company is already looking at commercializing this material printable in 3D, which is highly conductive and has various potential applications. The first step: take a thermoplastic and, with a solvent, transform it into a solution so that it becomes a liquid. Second step: as a result of the porousness of this thermoplastic solution, carbon nanotubes can be incorporated into it like never before, somewhat like adding sugar into a cake mix. The result: a kind of black ink that’s fairly viscous and whose very high conductivity approximates that of some metals. Third step: this black ink, which is in fact a nanocomposite, can now move on to 3D printing. As soon as it comes out of the printing nozzle, the solvent evaporates and the ink solidifies. It takes the form of filaments slightly bigger than a hair. The manufacturing work can then begin.

Findings are described in the journal Small.

Source: http://www.polymtl.ca/

Bones Could Be 3D Printed With Unbreakable Materials

Scientists from Queen Mary University of London (QMUL) have discovered the secret behind the toughness of deer antlers and how they can resist breaking during fights.

3d-printed-bones

The fibrils that make up the antler are staggered rather than in line with each other. This allows them to absorb the energy from the impact of a clash during a fight,” said first author Paolino De Falco from QMUL‘s School of Engineering and Materials Science .

The research, published in the journal ACS Biomaterials Science & Engineering, provides new insights and fills a previous gap in the area of structural modelling of bone. It also opens up possibilities for the creation of a new generation of materials that can resist damage.

Co-author Dr Ettore Barbieri, also from QMUL‘s School of Engineering and Materials Science, comments: “Our next step is to create a 3D printed model with fibres arranged in staggered configuration and linked by an elastic interface. The aim is to prove that additive manufacturing – where a prototype can be created a layer at a time – can be used to create damage resistant composite material.”

Source: http://www.qmul.ac.uk/

Ultra Thin Nightvision Glasses Based On NanoPhotonics

Scientists from the Australian National University (ANU) have designed a nano crystal around 500 times smaller than a human hair that turns darkness into visible light and can be used to create light-weight night-vision glasses. Professor Dragomir Neshev from ANU said the new night-vision glasses could replace the cumbersome and bulky night-vision binoculars currently in use.

ultra-thin-nano-crystal-film_anu-1

The nano crystals are so small they could be fitted as an ultra-thin film to normal eye glasses to enable night vision,” said Professor Neshev from the Nonlinear Physics Centre within the ANU Research School of Physics and Engineering.

This tiny device could have other exciting uses including in anti-counterfeit devices in bank notes, imaging cells for medical applications and holograms.”

Co-researcher Dr Mohsen Rahmani said the ANU team’s achievement was a big milestone in the field of nanophotonics, which involves the study of behaviour of light and interaction of objects with light at the nano-scale.

nightvision-glasses

These semi-conductor nano-crystals can transfer the highest intensity of light and engineer complex light beams that could be used with a laser to project a holographic image in modern displays,” said Dr Rahmani, a recipient of the Australian Research Council (ARC) Discovery Early Career Researcher Award based at the ANU Research School of Physics and Engineering.

PhD student Maria del Rocio Camacho-Morales said the team built the device on glass so that light can pass through, which was critical for optical displays.

Source: http://www.anu.edu.au/

3D Printed Office

In Dubai the first fully 3D-printed and completely functional building has not only been built but has celebrated its grand opening, marking an architectural and engineering breakthrough. The prototype 3D-printed office building, with floorspace is about 2,700 square feet (250 m2).

UAE-Dubai-Office-of-the-Future-

The office has all the amenities of traditionally constructed structures, such as electricity, water, telecommunications, and air conditioning. The office is also outfitted with a number of energy saving features, including window shades to protect from Dubai’s blazing sun. In order to create all the pieces needed for the office, builders used a 3D printer measuring 20 feet high, 120 feet long, and 40 feet wide. Aside from the equipment, it took a very small team of workers to put the office together. Seven installers and 10 electricians and specialists worked together to assemble the fully functional office in just 17 days. Dubai’s media office estimates this represents a 50 percent cost savings in labor alone compared to buildings of similar size built with conventional methods. In Dubai 25% of the buildings should be 3D printed by 2030, says ruler.

Source: http://inhabitat.com/

Artificial Molecules Revolutionize 3D Printing

Scientists at ETH Zurich and IBM Research Zurich have developed a new technique that enables for the first time the manufacture of complexly structured tiny objects joining together microspheres. The objects have a size of just a few micrometres and are produced in a modular fashion, making it possible to program their design in such a way that each component exhibits different physical properties. After fabrication, it is also very simple to bring the micro-objects into solution. This makes the new technique substantially different from micro 3D printing technology. With most of today’s micro 3D printing technologies, objects can only be manufactured if they consist of a single material, have a uniform structure and are attached to a surface during production.

3D printing process ETHArtificial molecules. The individual components are marked with different fluorescent dyes (molecule size: 2-7 micrometres; compilation of microscopic images)

To prepare the micro-objects, the ETH and IBM researchers use tiny spheres made from a polymer or silica as their building blocks, each with a diameter of approximately one micrometre and different physical properties. The scientists are able to control the particles and arrange them in the geometry and sequence they like.

The structures that are formed occupy an interesting niche in the size scale: they are much larger than your typical chemical or biochemical molecules, but much smaller than typical objects in the macroscopic world. “Depending on the perspective, it’s possible to speak of giant molecules or micro-objects,” says Lucio Isa, Professor for Interfaces, Soft matter and Assembly at ETH Zurich. He headed the research project together with Heiko Wolf, a scientist at IBM Research. “So far, no scientist has succeeded in fully controlling the sequence of individual components when producing artificial molecules on the micro scale,” says Isa.

Source: https://www.ethz.ch/

How To 3D Print Bones, Muscles, Cartilage

A new method of 3D printing can produce human-sized bone, muscle, and cartilage templates that survive when implanted into animals, researchers report.

3D ear

It has been challenging to produce human scale tissues with 3D printing because larger tissues require additional nutrition,” said Dr. Anthony Atala from Wake Forest School of Medicine, Winston-Salem, North Carolina.

His team developed a process they call “the integrated tissue and organ printing system,” or ITOP for short. ITOP produces a network of tiny channels that allows the printed tissue to be nourished after being implanted into a living animal. The researchers produced three types of tissuebone, cartilage, and muscle – and transplanted it into rats and mice. Five months after implantation, the bone tissue looked similar to normal bone, complete with blood vessels and with no dead areas, the research team reported in Nature Biotechnology.

Results with 3D-printed skeletal muscle were equally impressive. Not only did the implants look like normal muscle when examined two weeks after implantation, but the implants also contracted like immature, developing muscle when stimulated.

It is often frustrating for physicians to have patients receive a plastic or metal part during surgery knowing that the best replacement would have been the patient’s own tissue,” Dr. Atala said. “The results of this study bring us closer to the reality of using 3D printing to repair defects using the patient’s own engineered tissue.” “We are also using similar strategies to print solid organs”,  he added.

Source: http://www.reuters.com/

3D Printed Prosthetic Leg For Dog

After losing both her front legs in an accident three years ago, doctors are fitting Romina with a one-of-a-kind 3D printed prosthetic leg, that will help her get back on her feet. And as Fernanda Ortiz, one of the specialists treating the Greyhound Whippet at the Universidad Del Valle De Mexico explains, it will enable her joints to move in a way that mimics what natural limbs do.

3D prosthetic limb

 

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When she flexes her elbow, the whole prosthesis flexes and so she has to learn to make this movement in order to learn how to use it. Obviously, we’re unable to tell her: ‘Flex and walk normally with your elbow,’ because she doesn’t understand and so it’s very important for us – through exercises and indications – to show her how to do it“, says Fernanda Ortiz, Head of the Department of Rehabilitation at the Veterinary Hospital of the Universidad Del Valle De Mexico (UVM).
Romina’s left limb was rebuilt using titanium plates, which joined the limb but resulted in her losing all movement in that leg. It took about six months for a multidisciplinary team to design and develop prototypes. Prosthetics specialist Santiago Garcia says that printing the model in 3D, made adjusting the prototypes easy.
When we have the 3D model of the patient’s limb, we are able to adjust the size of the piece to the patient, in terms of millimeters. It’s a limb that is designed especially for this patient. Secondly and this is very important, it allows us to adjust it quickly. If I re-print a piece and I detect it has – for example, two millimeters in size I have to repair, it’s much easier for me to print it in a 3D printer than to redesign the mold and the whole traditional process“, comments Santiago Garcia,  specialist in prosthetics at UVM.  Once Romina adjusts to her new limb, the team will prepare a final prosthesis designed in aluminum, which will be covered with skin-like material.

Source: http://www.reuters.com