Monkeys 'move and feel' virtual objects using only their brains

ScienceDaily (Oct. 6, 2011) — In a first ever demonstration of a two-way interaction between a primate brain and a virtual body, two monkeys trained at the Duke University Center for Neuroengineering learned to employ brain activity alone to move an avatar hand and identify the texture of virtual objects.

"Someday in the near future, quadriplegic patients will take advantage of this technology not only to move their arms and hands and to walk again, but also to sense the texture of objects placed in their hands, or experience the nuances of the terrain on which they stroll with the help of a wearable robotic exoskeleton," said Miguel Nicolelis, M.D., Ph.D., professor of neurobiology at Duke University Medical Center and co-director of the Duke Center for Neuroengineering, who was senior author of the study.

Without moving any part of their real bodies, the monkeys used their electrical brain activity to direct the virtual hands of an avatar to the surface of virtual objects and, upon contact, were able to differentiate their textures.

Although the virtual objects employed in this study were visually identical, they were designed to have different artificial textures that could only be detected if the animals explored them with virtual hands controlled directly by their brain's electrical activity.

The texture of the virtual objects was expressed as a pattern of minute electrical signals transmitted to the monkeys' brains. Three different electrical patterns corresponded to each of three different object textures.

Because no part of the animal's real body was involved in the operation of this brain-machine-brain interface (BMBI), these experiments suggest that in the future patients severely paralyzed due to a spinal cord lesion may take advantage of this technology, not only to regain mobility, but also to have their sense of touch restored, said Nicolelis, who was senior author of the study published in the journal Nature on Oct. 5.

"This is the first demonstration of a brain-machine-brain interface that establishes a direct, bidirectional link between a brain and a virtual body," Nicolelis said. "In this BMBI, the virtual body is controlled directly by the animal's brain activity, while its virtual hand generates tactile feedback information that is signaled via direct electrical microstimulation of another region of the animal's cortex."

"We hope that in the next few years this technology could help to restore a more autonomous life to many patients who are currently locked in without being able to move or experience any tactile sensation of the surrounding world," Nicolelis said.

"This is also the first time we've observed a brain controlling a virtual arm that explores objects while the brain simultaneously receives electrical feedback signals that describe the fine texture of objects 'touched' by the monkey's newly acquired virtual hand," Nicolelis said. "Such an interaction between the brain and a virtual avatar was totally independent of the animal's real body, because the animals did not move their real arms and hands, nor did they use their real skin to touch the objects and identify their texture. It's almost like creating a new sensory channel through which the brain can resume processing information that cannot reach it anymore through the real body and peripheral nerves."

The combined electrical activity of populations of 50-200 neurons in the monkey's motor cortex controlled the steering of the avatar arm, while thousands of neurons in the primary tactile cortex were simultaneously receiving continuous electrical feedback from the virtual hand's palm that let the monkey discriminate between objects, based on their texture alone.

"The remarkable success with non-human primates is what makes us believe that humans could accomplish the same task much more easily in the near future," Nicolelis said.

It took one monkey only four attempts and another nine attempts before they learned how to select the correct object during each trial. Several tests demonstrated that the monkeys were actually sensing the object and not selecting them randomly.

The findings provide further evidence that it may be possible to create a robotic exoskeleton that severely paralyzed patients could wear in order to explore and receive feedback from the outside world, Nicolelis said. Such an exoskeleton would be directly controlled by the patient's voluntary brain activity in order to allow the patient to move autonomously. Simultaneously, sensors distributed across the exoskeleton would generate the type of tactile feedback needed for the patient's brain to identify the texture, shape and temperature of objects, as well as many features of the surface upon which they walk.

This overall therapeutic approach is the one chosen by the Walk Again Project, an international, non-profit consortium, established by a team of Brazilian, American, Swiss, and German scientists, which aims at restoring full body mobility to quadriplegic patients through a brain-machine-brain interface implemented in conjunction with a full-body robotic exoskeleton.

The international scientific team recently proposed to carry out its first public demonstration of such an autonomous exoskeleton during the opening game of the 2014 FIFA Soccer World Cup that will be held in Brazil.

Other authors include Joseph E. O'Doherty, Mikhail A. Lebedev, Peter J. Ifft, Katie Z. Zhuang, all from the Duke University Center for Neuroengineering and Solaiman Shokur, and Hannes Bleuler from the Ecole Polytechnic Federale de Lausanne (EPFL), in Lausanne, Switzerland.

This work was funded by the U.S. National Institutes of Health.

A video illustrating the experiment is available at: http://www.youtube.com/watch?v=WTTTwvjCa5g

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Story Source:

The above story is reprinted (with editorial adaptations by ScienceDaily staff) from materials provided by Duke University Medical Center.

Journal Reference:

Joseph E. O’Doherty, Mikhail A. Lebedev, Peter J. Ifft, Katie Z. Zhuang, Solaiman Shokur, Hannes Bleuler, Miguel A. L. Nicolelis. Active tactile exploration using a brain–machine–brain interface. Nature, 2011; DOI: 10.1038/nature10489

Note: If no author is given, the source is cited instead.

Disclaimer: This article is not intended to provide medical advice, diagnosis or treatment. Views expressed here do not necessarily reflect those of ScienceDaily or its staff.

View the original article here

Communication Between People and Objects: A Symposium

The Museum of Modern Art's exhibition "Talk To Me" explores the complicated interactions between machines and their humans in a fun and fascinating way. Next week, the museum's holding an all-day symposium, open to the public.

It will feature discussions and presentations by curator Paola Antonelli and some 20 other luminaries, including chef Marcus Samuelsson, artist Natalie Jeremijenko, and performer Sputniko. Subjects covered will include "design and script writing, cognitive science, gaming, augmented reality, and communication." The keynote address will be delivered by Radiolab host Jad Abumrad, who just received a MacArthur grant.

Hopefully the adorable Tweenbot (seen below) will put in an appearance as well.

View the original article here

Monkeys 'move and feel' virtual objects using only their brains

ScienceDaily (Oct. 6, 2011) — In a first ever demonstration of a two-way interaction between a primate brain and a virtual body, two monkeys trained at the Duke University Center for Neuroengineering learned to employ brain activity alone to move an avatar hand and identify the texture of virtual objects.

"Someday in the near future, quadriplegic patients will take advantage of this technology not only to move their arms and hands and to walk again, but also to sense the texture of objects placed in their hands, or experience the nuances of the terrain on which they stroll with the help of a wearable robotic exoskeleton," said Miguel Nicolelis, M.D., Ph.D., professor of neurobiology at Duke University Medical Center and co-director of the Duke Center for Neuroengineering, who was senior author of the study.

Without moving any part of their real bodies, the monkeys used their electrical brain activity to direct the virtual hands of an avatar to the surface of virtual objects and, upon contact, were able to differentiate their textures.

Although the virtual objects employed in this study were visually identical, they were designed to have different artificial textures that could only be detected if the animals explored them with virtual hands controlled directly by their brain's electrical activity.

The texture of the virtual objects was expressed as a pattern of minute electrical signals transmitted to the monkeys' brains. Three different electrical patterns corresponded to each of three different object textures.

Because no part of the animal's real body was involved in the operation of this brain-machine-brain interface (BMBI), these experiments suggest that in the future patients severely paralyzed due to a spinal cord lesion may take advantage of this technology, not only to regain mobility, but also to have their sense of touch restored, said Nicolelis, who was senior author of the study published in the journal Nature on Oct. 5.

"This is the first demonstration of a brain-machine-brain interface that establishes a direct, bidirectional link between a brain and a virtual body," Nicolelis said. "In this BMBI, the virtual body is controlled directly by the animal's brain activity, while its virtual hand generates tactile feedback information that is signaled via direct electrical microstimulation of another region of the animal's cortex."

"We hope that in the next few years this technology could help to restore a more autonomous life to many patients who are currently locked in without being able to move or experience any tactile sensation of the surrounding world," Nicolelis said.

"This is also the first time we've observed a brain controlling a virtual arm that explores objects while the brain simultaneously receives electrical feedback signals that describe the fine texture of objects 'touched' by the monkey's newly acquired virtual hand," Nicolelis said. "Such an interaction between the brain and a virtual avatar was totally independent of the animal's real body, because the animals did not move their real arms and hands, nor did they use their real skin to touch the objects and identify their texture. It's almost like creating a new sensory channel through which the brain can resume processing information that cannot reach it anymore through the real body and peripheral nerves."

The combined electrical activity of populations of 50-200 neurons in the monkey's motor cortex controlled the steering of the avatar arm, while thousands of neurons in the primary tactile cortex were simultaneously receiving continuous electrical feedback from the virtual hand's palm that let the monkey discriminate between objects, based on their texture alone.

"The remarkable success with non-human primates is what makes us believe that humans could accomplish the same task much more easily in the near future," Nicolelis said.

It took one monkey only four attempts and another nine attempts before they learned how to select the correct object during each trial. Several tests demonstrated that the monkeys were actually sensing the object and not selecting them randomly.

The findings provide further evidence that it may be possible to create a robotic exoskeleton that severely paralyzed patients could wear in order to explore and receive feedback from the outside world, Nicolelis said. Such an exoskeleton would be directly controlled by the patient's voluntary brain activity in order to allow the patient to move autonomously. Simultaneously, sensors distributed across the exoskeleton would generate the type of tactile feedback needed for the patient's brain to identify the texture, shape and temperature of objects, as well as many features of the surface upon which they walk.

This overall therapeutic approach is the one chosen by the Walk Again Project, an international, non-profit consortium, established by a team of Brazilian, American, Swiss, and German scientists, which aims at restoring full body mobility to quadriplegic patients through a brain-machine-brain interface implemented in conjunction with a full-body robotic exoskeleton.

The international scientific team recently proposed to carry out its first public demonstration of such an autonomous exoskeleton during the opening game of the 2014 FIFA Soccer World Cup that will be held in Brazil.

Other authors include Joseph E. O'Doherty, Mikhail A. Lebedev, Peter J. Ifft, Katie Z. Zhuang, all from the Duke University Center for Neuroengineering and Solaiman Shokur, and Hannes Bleuler from the Ecole Polytechnic Federale de Lausanne (EPFL), in Lausanne, Switzerland.

This work was funded by the U.S. National Institutes of Health.

A video illustrating the experiment is available at: http://www.youtube.com/watch?v=WTTTwvjCa5g

Recommend this story on Facebook, Twitter,
and Google +1:

Other bookmarking and sharing tools:

Story Source:

The above story is reprinted (with editorial adaptations by ScienceDaily staff) from materials provided by Duke University Medical Center.

Journal Reference:

Joseph E. O’Doherty, Mikhail A. Lebedev, Peter J. Ifft, Katie Z. Zhuang, Solaiman Shokur, Hannes Bleuler, Miguel A. L. Nicolelis. Active tactile exploration using a brain–machine–brain interface. Nature, 2011; DOI: 10.1038/nature10489

Note: If no author is given, the source is cited instead.

Disclaimer: This article is not intended to provide medical advice, diagnosis or treatment. Views expressed here do not necessarily reflect those of ScienceDaily or its staff.

View the original article here

Faster computer graphics: Digitally mimicking photographic blur caused by moving objects

ScienceDaily (June 13, 2011) — Photographs of moving objects are almost always a little blurry -- or a lot blurry, if the objects are moving rapidly enough. To make their work look as much like conventional film as possible, game and movie animators try to reproduce this blur. But counterintuitively, producing blurry images is actually more computationally complex than producing perfectly sharp ones.

In August, at this year's Siggraph conference -- the premier computer-graphics conference -- researchers from the Computer Graphics Group at MIT's Computer Science and Artificial Intelligence Laboratory will present a pair of papers that describe new techniques for computing blur much more efficiently. The result could be more convincing video games and frames of digital video that take minutes rather than hours to render.

The image sensor in a digital camera, and even the film in a conventional camera, can be thought of as a grid of color detectors, each detector corresponding to one pixel in the final image. If the objects being photographed are stationary, then during a single exposure, each detector registers the color of just one point on an object's surface. But if the objects are moving, light from different points on an object, and even from different objects, will strike a single detector. The detector effectively averages the colors of all the points, and the result is blur.

Digitally rendering a frame of video is a computationally intensive process with several discrete stages. First, the computer has to determine how the objects in the scene are moving. Second, it has to calculate how rays of light from an imagined light source would reflect off the objects. Finally, it determines which rays of light would actually reach an imagined lens. If the objects in the video are moving slowly enough, the computer has to go through that process only once per frame. If the objects are moving rapidly, however, it may have to go through it dozens or even hundreds of times.

Colorfast

Given how difficult blurring is to calculate, you might think that animators would simply ignore it. But that leads to surprisingly unconvincing video. "The motion doesn't look fluid at all," says Jaakko Lehtinen, who worked on both projects as a postdoc in the Computer Graphics Group and is now a senior research scientist with graphics-chip manufacturer Nvidia.

To get a sense of what motion without blur looks like, Lehtinen says, consider the type of clay animation familiar from old movies or Christmas specials such as "Rudolph the Red-Nosed Reindeer." "This doesn't have motion blur, because the scene is actually stationary when you take the picture," Lehtinen says. "It just looks choppy. The motion doesn't look natural."

The MIT researchers took two different approaches to simplifying the computation of blur, corresponding to two different stages in the graphics-rendering pipeline. Graduate student Jonathan Ragan-Kelley is the lead author on one of the Siggraph papers, joined by associate professor Frédo Durand, who leads the Computer Graphics Group; Lehtinen; graduate student Jiawen Chen; and Michael Doggett of Lund University in Sweden. In that paper, the researchers make the simplifying assumption that the way in which light reflects off a moving object doesn't change over the course of a single frame. For each pixel in the final image, their algorithm still averages the colors of multiple points on objects' surfaces, but it calculates those colors only once. The researchers found a way to represent the relationship between the color calculations and the shapes of the associated objects as entries in a table. For each pixel in the final image, the algorithm simply looks up the corresponding values in the table. That drastically simplifies the calculation but has little effect on the final image.

Adopting the researchers' proposal would require modifying the architecture of graphics chips. "You can imagine really just going ahead and building what they suggest," says Henry Moreton, a distinguished engineer at Nvidia. "But I think that the greater value of the paper is that it points at strategies for solving these problems more elegantly, more efficiently, and more practically. Whether they manifest themselves in exactly the fashion that the paper presents is probably not that likely. But what they did is they pointed to a new way of attacking the problem."

Turning the tables

The second of the Computer Graphics Group's Siggraph papers, led by Lehtinen and also featuring Durand, Chen and two of Lehtinen's Nvidia colleagues, reduces the computational burden of determining which rays of light would reach an imagined lens. To produce convincing motion blur, digital animators might ordinarily consider the contributions that more than 100 discrete points on the surfaces of moving objects make to the color value of a single pixel. Lehtinen and his colleagues' algorithm instead looks at a smaller number of points -- maybe 16 or so -- and makes an educated guess about the color values of the points in between. The result: A frame of digital video that would ordinarily take about an hour to render might instead take about 10 minutes.

In fact, both techniques apply not only to motion blur but also to the type of blur that occurs in, say, the background of an image when the camera is focused on an object in the foreground. That, too, is something that animators seek to reproduce. "Where the director and the cinematographer choose to focus the lens, it directs your attention when you're looking at the picture in subtle ways," Lehtinen says. If an animated film has no such lapses in focus, "there's just something wrong with it," Lehtinen says. "It doesn't look like a movie." Indeed, Lehtinen says, even though the paper has yet to be presented, several major special-effects companies have already contacted the researchers about the work.

Story Source:

The above story is reprinted (with editorial adaptations by ScienceDaily staff) from materials provided by Massachusetts Institute of Technology. The original article was written by Larry Hardesty, MIT News Office.

Note: If no author is given, the source is cited instead.

Disclaimer: Views expressed in this article do not necessarily reflect those of ScienceDaily or its staff.

View the original article here

Faster computer graphics: Digitally mimicking photographic blur caused by moving objects

ScienceDaily (June 13, 2011) — Photographs of moving objects are almost always a little blurry -- or a lot blurry, if the objects are moving rapidly enough. To make their work look as much like conventional film as possible, game and movie animators try to reproduce this blur. But counterintuitively, producing blurry images is actually more computationally complex than producing perfectly sharp ones.

In August, at this year's Siggraph conference -- the premier computer-graphics conference -- researchers from the Computer Graphics Group at MIT's Computer Science and Artificial Intelligence Laboratory will present a pair of papers that describe new techniques for computing blur much more efficiently. The result could be more convincing video games and frames of digital video that take minutes rather than hours to render.

The image sensor in a digital camera, and even the film in a conventional camera, can be thought of as a grid of color detectors, each detector corresponding to one pixel in the final image. If the objects being photographed are stationary, then during a single exposure, each detector registers the color of just one point on an object's surface. But if the objects are moving, light from different points on an object, and even from different objects, will strike a single detector. The detector effectively averages the colors of all the points, and the result is blur.

Digitally rendering a frame of video is a computationally intensive process with several discrete stages. First, the computer has to determine how the objects in the scene are moving. Second, it has to calculate how rays of light from an imagined light source would reflect off the objects. Finally, it determines which rays of light would actually reach an imagined lens. If the objects in the video are moving slowly enough, the computer has to go through that process only once per frame. If the objects are moving rapidly, however, it may have to go through it dozens or even hundreds of times.

Colorfast

Given how difficult blurring is to calculate, you might think that animators would simply ignore it. But that leads to surprisingly unconvincing video. "The motion doesn't look fluid at all," says Jaakko Lehtinen, who worked on both projects as a postdoc in the Computer Graphics Group and is now a senior research scientist with graphics-chip manufacturer Nvidia.

To get a sense of what motion without blur looks like, Lehtinen says, consider the type of clay animation familiar from old movies or Christmas specials such as "Rudolph the Red-Nosed Reindeer." "This doesn't have motion blur, because the scene is actually stationary when you take the picture," Lehtinen says. "It just looks choppy. The motion doesn't look natural."

The MIT researchers took two different approaches to simplifying the computation of blur, corresponding to two different stages in the graphics-rendering pipeline. Graduate student Jonathan Ragan-Kelley is the lead author on one of the Siggraph papers, joined by associate professor Frédo Durand, who leads the Computer Graphics Group; Lehtinen; graduate student Jiawen Chen; and Michael Doggett of Lund University in Sweden. In that paper, the researchers make the simplifying assumption that the way in which light reflects off a moving object doesn't change over the course of a single frame. For each pixel in the final image, their algorithm still averages the colors of multiple points on objects' surfaces, but it calculates those colors only once. The researchers found a way to represent the relationship between the color calculations and the shapes of the associated objects as entries in a table. For each pixel in the final image, the algorithm simply looks up the corresponding values in the table. That drastically simplifies the calculation but has little effect on the final image.

Adopting the researchers' proposal would require modifying the architecture of graphics chips. "You can imagine really just going ahead and building what they suggest," says Henry Moreton, a distinguished engineer at Nvidia. "But I think that the greater value of the paper is that it points at strategies for solving these problems more elegantly, more efficiently, and more practically. Whether they manifest themselves in exactly the fashion that the paper presents is probably not that likely. But what they did is they pointed to a new way of attacking the problem."

Turning the tables

The second of the Computer Graphics Group's Siggraph papers, led by Lehtinen and also featuring Durand, Chen and two of Lehtinen's Nvidia colleagues, reduces the computational burden of determining which rays of light would reach an imagined lens. To produce convincing motion blur, digital animators might ordinarily consider the contributions that more than 100 discrete points on the surfaces of moving objects make to the color value of a single pixel. Lehtinen and his colleagues' algorithm instead looks at a smaller number of points -- maybe 16 or so -- and makes an educated guess about the color values of the points in between. The result: A frame of digital video that would ordinarily take about an hour to render might instead take about 10 minutes.

In fact, both techniques apply not only to motion blur but also to the type of blur that occurs in, say, the background of an image when the camera is focused on an object in the foreground. That, too, is something that animators seek to reproduce. "Where the director and the cinematographer choose to focus the lens, it directs your attention when you're looking at the picture in subtle ways," Lehtinen says. If an animated film has no such lapses in focus, "there's just something wrong with it," Lehtinen says. "It doesn't look like a movie." Indeed, Lehtinen says, even though the paper has yet to be presented, several major special-effects companies have already contacted the researchers about the work.

Story Source:

The above story is reprinted (with editorial adaptations by ScienceDaily staff) from materials provided by Massachusetts Institute of Technology. The original article was written by Larry Hardesty, MIT News Office.

Note: If no author is given, the source is cited instead.

Disclaimer: Views expressed in this article do not necessarily reflect those of ScienceDaily or its staff.

View the original article here

Diminutive 3-D printers to enable home manufacturing of custom objects

ScienceDaily (May 18, 2011) — A research project at the Vienna University of Technology (TU Vienna) could turn futuristic 3-D printers into affordable everyday items. Printers, which can produce three-dimensional objects have been available for years. However, at the Vienna University of Technology, a printing device has now been developed, which is much smaller, lighter and cheaper than ordinary 3-D printers. With this kind of printer, everyone could produce small, tailor-made 3-D objects at home, using building plans from the internet -- and this could save money for expensive custom-built spare parts.

Several scientific fields have to come together, to design a 3-D printer. The device was assembled by mechanical engineers in the research group of professor Jürgen Stampfl, but also the chemical research by the team of professor Robert Liska was of crucial importance: first, chemists have to determine which special kinds of synthetic material can be used for printing.

Layer for Layer

The basic principle of the 3-D printer is quite simple: The desired object is printed in a small tub filled with synthetic resin. The resin has a very special property: It hardens precisely where it is illuminated with intense beams of light. Layer for layer, the synthetic resin is irradiated at exactly the right spots. When one layer hardens, the next layer can be attached to it, until the object is completed. This method is called "additive manufacturing technology." "This way, we can even produce complicated geometrical objects with an intricate inner structure, which could never be made using casting techniques," Klaus Stadlmann explains. He developed the prototype together with Markus Hatzenbichler.

This method is not designed for large-scale production of bulk articles -- for that, there are cheaper alternatives. The great advantage of additive manufacturing is the fact that is offers the possibility to produce tailor-made, individually adjusted items. The prototype of the printer is no bigger than a carton of milk, it weighs 1.5 kilograms, and at just 1200 Euros, it was remarkably cheap. "We will continue to reduce the size of the printer, and the price will definitely decrease too, if it is produced in large quantities," Klaus Stadlmann believes.

LED-Projector for Higher Resolution

The printer's resolution is excellent: The individual layers hardened by the light beams are just a twentieth of a millimetre thick. Therefore, the printer can be used for applications which require extraordinary precision -- such as construction parts for hearing aids. Unlike previous models, the printer at TU Vienna uses light emitting diodes, with which high intensities of light can be obtained at very well-defined positions.

The research group for additive manufacturing technologies at TU Vienna is working with a variety of different 3-D techniques and materials. New materials -- such as special ceramics or polymers -- are constantly being developed for 3-D printing. 3-D objects can now even be made from eco-friendly biodegradable substances. In cooperation with biologists and physicians, the scientists could show that the artificial structures created with their 3-D printer technology are perfectly suited to serve as a scaffold that supports natural growth of bone structure in the body.

Remarkable Versatility

No matter whether it is medical parts, adjusted exactly to the patient's needs, special spare parts which otherwise would have to be shipped around half the globe, or whether it is just some kind of self-designed bling jewelery: with the versatile and cheap devices and materials developed in Vienna, highly complex 3-D objects can now be built from a variety of materials with very different mechanical, optical and thermal properties.

Story Source:

The above story is reprinted (with editorial adaptations by ScienceDaily staff) from materials provided by Vienna University of Technology, TU Vienna.

Note: If no author is given, the source is cited instead.

Disclaimer: Views expressed in this article do not necessarily reflect those of ScienceDaily or its staff.

View the original article here

Diminutive 3-D printers to enable home manufacturing of custom objects

ScienceDaily (May 18, 2011) — A research project at the Vienna University of Technology (TU Vienna) could turn futuristic 3-D printers into affordable everyday items. Printers, which can produce three-dimensional objects have been available for years. However, at the Vienna University of Technology, a printing device has now been developed, which is much smaller, lighter and cheaper than ordinary 3-D printers. With this kind of printer, everyone could produce small, tailor-made 3-D objects at home, using building plans from the internet -- and this could save money for expensive custom-built spare parts.

Several scientific fields have to come together, to design a 3-D printer. The device was assembled by mechanical engineers in the research group of professor Jürgen Stampfl, but also the chemical research by the team of professor Robert Liska was of crucial importance: first, chemists have to determine which special kinds of synthetic material can be used for printing.

Layer for Layer

The basic principle of the 3-D printer is quite simple: The desired object is printed in a small tub filled with synthetic resin. The resin has a very special property: It hardens precisely where it is illuminated with intense beams of light. Layer for layer, the synthetic resin is irradiated at exactly the right spots. When one layer hardens, the next layer can be attached to it, until the object is completed. This method is called "additive manufacturing technology." "This way, we can even produce complicated geometrical objects with an intricate inner structure, which could never be made using casting techniques," Klaus Stadlmann explains. He developed the prototype together with Markus Hatzenbichler.

This method is not designed for large-scale production of bulk articles -- for that, there are cheaper alternatives. The great advantage of additive manufacturing is the fact that is offers the possibility to produce tailor-made, individually adjusted items. The prototype of the printer is no bigger than a carton of milk, it weighs 1.5 kilograms, and at just 1200 Euros, it was remarkably cheap. "We will continue to reduce the size of the printer, and the price will definitely decrease too, if it is produced in large quantities," Klaus Stadlmann believes.

LED-Projector for Higher Resolution

The printer's resolution is excellent: The individual layers hardened by the light beams are just a twentieth of a millimetre thick. Therefore, the printer can be used for applications which require extraordinary precision -- such as construction parts for hearing aids. Unlike previous models, the printer at TU Vienna uses light emitting diodes, with which high intensities of light can be obtained at very well-defined positions.

The research group for additive manufacturing technologies at TU Vienna is working with a variety of different 3-D techniques and materials. New materials -- such as special ceramics or polymers -- are constantly being developed for 3-D printing. 3-D objects can now even be made from eco-friendly biodegradable substances. In cooperation with biologists and physicians, the scientists could show that the artificial structures created with their 3-D printer technology are perfectly suited to serve as a scaffold that supports natural growth of bone structure in the body.

Remarkable Versatility

No matter whether it is medical parts, adjusted exactly to the patient's needs, special spare parts which otherwise would have to be shipped around half the globe, or whether it is just some kind of self-designed bling jewelery: with the versatile and cheap devices and materials developed in Vienna, highly complex 3-D objects can now be built from a variety of materials with very different mechanical, optical and thermal properties.

Story Source:

The above story is reprinted (with editorial adaptations by ScienceDaily staff) from materials provided by Vienna University of Technology, TU Vienna.

Note: If no author is given, the source is cited instead.

Disclaimer: Views expressed in this article do not necessarily reflect those of ScienceDaily or its staff.

View the original article here