Regular 3D printers use plastic that is built up [...]]]> A company called Invetech has created what looks to be a human tissue printer that works in a similar way to how 3D printers work. The system is capable of building up human organs cell by cell to create scaffolds that liver cells could be placed on.

Regular 3D printers use plastic that is built up layer by layer over the course of the printing session to create unique 3D objects. The new system replaces this “3D ink” with living cells so that Dr’s can print human tissue on demand.

“Scientists and engineers can use the 3D bio printers to enable placing cells of almost any type into a desired pattern in 3D,” Murphy said. “Researchers can place liver cells on a preformed scaffold, support kidney cells with a co-printed scaffold, or form adjacent layers of epithelial and stromal soft tissue that grow into a mature tooth. Ultimately the idea would be for surgeons to have tissue on demand for various uses, and the best way to do that is get a number of bio-printers into the hands of researchers and give them the ability to make three dimensional tissues on demand.”

An interesting point to make here is that the model is a production model and already delivered to a company called Organovo who in turn will supply the machines to researchers investigating human tissue repair and organ replacement.

The 3D bio-printers include an intuitive software interface that allows engineers to build a model of the tissue construct before the printer commences the physical constructions of the organs cell-by-cell using automated, laser-calibrated print heads.

“Building human organs cell-by-cell was considered science fiction not that long ago,” said Fred Davis, president of Invetech, which has offices in San Diego and Melbourne. “Through this clever combination of technology and science we have helped Organovo develop an instrument that will improve people’s lives, making the regenerative medicine that Organovo provides accessible to people around the world.”

Via: livescience.com

Stereolithography

Patented in 1986, stereolithography started the rapid prototyping revolution. The technique builds three-dimensional models from liquid photosensitive polymers that solidify when exposed [...]]]> Most commercially available rapid prototyping machines use one of six techniques. At present, trade restrictions severely limit the import/export of rapid prototyping machines, so this guide only covers systems available in the U.S.

Stereolithography

Patented in 1986, stereolithography started the rapid prototyping revolution. The technique builds three-dimensional models from liquid photosensitive polymers that solidify when exposed to ultraviolet light. As shown in the figure below, the model is built upon a platform situated just below the surface in a vat of liquid epoxy or acrylate resin. A low-power highly focused UV laser traces out the first layer, solidifying the model’s cross section while leaving excess areas liquid.

Laminated Object Manufacturing

In this technique, developed by Helisys of Torrance, CA, layers of adhesive-coated sheet material are bonded together to form a prototype. The original material consists of paper laminated with heat-activated glue and rolled up on spools. As shown in the figure below, a feeder/collector mechanism advances the sheet over the build platform, where a base has been constructed from paper and double-sided foam tape. Next, a heated roller applies pressure to bond the paper to the base. A focused laser cuts the outline of the first layer into the paper and then cross-hatches the excess area (the negative space in the prototype). Cross-hatching breaks up the extra material, making it easier to remove during post-processing. During the build, the excess material provides excellent support for overhangs and thin-walled sections. After the first layer is cut, the platform lowers out of the way and fresh material is advanced. The platform rises to slightly below the previous height, the roller bonds the second layer to the first, and the laser cuts the second layer. This process is repeated as needed to build the part, which will have a wood-like texture. Because the models are made of paper, they must be sealed and finished with paint or varnish to prevent moisture damage.

Selective Laser Sintering

Developed by Carl Deckard for his master’s thesis at the University of Texas, selective laser sintering was patented in 1989. The technique, shown in Figure 3, uses a laser beam to selectively fuse powdered materials, such as nylon, elastomer, and metal, into a solid object. Parts are built upon a platform which sits just below the surface in a bin of the heat-fusable powder. A laser traces the pattern of the first layer, sintering it together. The platform is lowered by the height of the next layer and powder is reapplied. This process continues until the part is complete. Excess powder in each layer helps to support the part during the build. SLS machines are produced by DTM of Austin, TX.

Fused Deposition Modeling

In this technique, filaments of heated thermoplastic are extruded from a tip that moves in the x-y plane. Like a baker decorating a cake, the controlled extrusion head deposits very thin beads of material onto the build platform to form the first layer. The platform is maintained at a lower temperature, so that the thermoplastic quickly hardens. After the platform lowers, the extrusion head deposits a second layer upon the first. Supports are built along the way, fastened to the part either with a second, weaker material or with a perforated junction.

Solid Ground Curing

Developed by Cubital, solid ground curing (SGC) is somewhat similar to stereolithography (SLA) in that both use ultraviolet light to selectively harden photosensitive polymers. Unlike SLA, SGC cures an entire layer at a time. Figure 5 depicts solid ground curing, which is also known as the solider process. First, photosensitive resin is sprayed on the build platform. Next, the machine develops a photomask (like a stencil) of the layer to be built. This photomask is printed on a glass plate above the build platform using an electrostatic process similar to that found in photocopiers. The mask is then exposed to UV light, which only passes through the transparent portions of the mask to selectively harden the shape of the current layer.

3-D Ink-Jet Printing

Ink-Jet Printing refers to an entire class of machines that employ ink-jet technology. The first was 3D Printing (3DP), developed at MIT and licensed to Soligen Corporation, Extrude Hone, and others. The ZCorp 3D printer, produced by Z Corporation of Burlington, MA is an example of this technology. As shown in Figure 6a, parts are built upon a platform situated in a bin full of powder material. An ink-jet printing head selectively deposits or “prints” a binder fluid to fuse the powder together in the desired areas. Unbound powder remains to support the part

source: mne.psu.edu

Recently, more than 100 researchers from around the world have been working on a project called RepRap (Replicating Rapid-prototyper), which started in 2004. At the Cheltenham Science Festival in the UK, the [...]]]> As biologists are busy working on cloning living organisms, engineers are working on a mechanical counterpart – creating non-living things that can replicate themselves.

Recently, more than 100 researchers from around the world have been working on a project called RepRap (Replicating Rapid-prototyper), which started in 2004. At the Cheltenham Science Festival in the UK, the team displayed their creation: the world’s first 3D printer than can print pieces which can be assembled by hand to make an exact copy of the original printer.

The replica is no mule, either – it can also print another copy of itself.

So far, RepRap can only reproduce its plastic parts, and not its metal or electronics. It takes a human a few hours to assemble the copied pieces into another printer.

Nevertheless, RepRap is the first 3D printer that can reproduce its own components. And, with its pieces costing around $600, the printer is much less expensive than other 3D printers (which cost around $50,000). Besides replicating itself, it can also print plastic 3D objects including coat hooks, water-filter insects, children’s sandals, and much more.

The RepRap collaborators hope that the printer can be useful for reproducing plastic objects of just about any shape, especially for hobbyists and communities in the developing world.

People already “run their own CD burners, printing presses and photographic laboratories”, said Adrian Bowyer, the University of Bath mechanical engineer who launched the RepRap project. “There’s no reason they shouldn’t run their own factories as well.”

At RepRap.org , you can find more information, including instructions for building your own replicating RepRap printer.

Source: inventorspot.com

A 3D printer combines or fuses successive layers of material in a form of “additive manufacturing” [...]]]> North Technical High School’s Precision Machining Program recently received a modern Dimension 1200es 3D printer System.  In today’s field of engineering, architecture, and design, prototyping a three dimensional drawing is an essential step in the design process.

A 3D printer combines or fuses successive layers of material in a form of “additive manufacturing” to yield a functional three dimensional object that can be tested under real-world conditions.  The Dimension 1200es 3D printer accomplishes this task by creating a durable ABS plastic model from a Computer Assisted Drawing (CAD) file, thus yielding a solid model prototype that closely imitates the look, feel, and functionality of the desired end product.  Previous methods of producing a typical prototype took many man-hours, numerous tools, and highly skilled labor.  This older research and development process would cost companies enormous amounts of money.

3D printing gives research and development teams a cheaper and faster process for producing prototypes.  This technology is not only used in industrial design, but also has applications in other areas such as jewelry, footwear, architecture, automotive, aerospace.

Source: northtechnical.org

MINNEAPOLIS, Dec. 2, 2009 — At Autodesk University 2009, Stratasys (NASDAQ: SSYS) and Autodesk unveiled the world’s first full-scale turbo-prop aircraft engine model. It was produced using Stratasys FDM (Fused Deposition Modeling) technology.

The engine’s design was created using [...]]]> The propeller blade-span is over 10 feet in this project that demonstrates how far 3D modeling has advanced.

MINNEAPOLIS, Dec. 2, 2009 — At Autodesk University 2009, Stratasys (NASDAQ: SSYS) and Autodesk unveiled the world’s first full-scale turbo-prop aircraft engine model. It was produced using Stratasys FDM (Fused Deposition Modeling) technology.

The engine’s design was created using Autodesk Inventor 2010 mechanical design and engineering software, and it was produced on both Fortus 3D Production Systems and Dimension 3D Printers from Stratasys.

The engine model sets a new precedence in scale, and it showcases the potential of 3D printing.

“Our Inventor software with FDM technology takes design innovation to an entirely new level of sophistication,” says Autodesk’s Gonzalo Martinez, office of the CTO. “Today at Autodesk University we’ve shown that with FDM, you can create realistic 3D models of nearly any design. We believe that Stratasys FDM technology is the future of 3D printing and production.”

The engine’s gear box includes two sets of gears, which operate two sets of propellers that move in counter rotation to each other.

With an engine length of over 10 feet, a blade-span of 10.5 feet, and 188 components, the engine model is massive in size. It includes several large parts, such as six propeller blades, each measuring 4.5 feet.

Building this physical model with FDM helped improve its design by identifying four opportunities to make components fit or operate with better precision. Assembling a physical model helps design engineers be certain of component form, fit, and function.

The turbo-prop engine was designed by Nino Caldarola, a freelance designer for Autodesk.

He shared his concept with Autodesk who wanted to bring a full-scale model to life using Inventor software and FDM technology.

Caldarola’s design is a hybrid of newer engine and classic engine design and was partially inspired by the Piaggio Avanti II aircraft engine, the TP 500.

Caldarola worked with engineers at RedEye On Demand prototyping and production service, a business unit of Stratasys, to make adjustments that would ensure an accurate physical model.

Source: pddnet.com

According to Christian Weinand of the Insel [...]]]> With the help of their latest invention in science – a 3D printer, researchers managed to create the exact copy of a man’s thumb bones. The device can now be used to help surgeons restore damaged bones by creating their precise copies, which are made from the patient’s cells.

According to Christian Weinand of the Insel Hospital in Berne, Switzerland, who leads the team of scientists that replicated his thumb bone, theoretically it is possible to copy any bone. The scientist “grew” his substitute bones on the backs of laboratory mice. However, it is not always necessary to use a surrogate mouse. This is the case when a person, who lost a thumb, is able to replace it with his or her own toe. Currently surgeons are able to replace a thumb with the patient’s toe or by using bone fragments.

The new method implies a number of steps. Initially it is important to have a 3D image of the bone that is going to be copied. In case the bone has been damaged, one can create a mirror image of the bone’s intact twin. Afterwards the picture of the bone is inserted into a 3D inject printer that puts thin layers of a material (selected beforehand) on top of one another till the 3D object shows up.

The researcher filled their latest invention with tricalcium phosphate along with a type of polylactic acid. These are natural materials that persist in human body, informs NewScientist.

After successfully replicating a bone, the copy itself features small pores on its “scaffolds”. This is where bone cells can eventually settle, grow and then completely displace the biodegradable scaffold. Scientists removed CD117 cells from bone marrow that remained after hip-replacement surgical operations. These cells develop into primordial bone cells, also known as osteoblasts. The latter were syringed on top of the bone scaffolds in a gel that was created to nourish the CD117 cells as well as support them. In the final step, scientists sew scaffolds under the skin on the backs of laboratory mice. After 15 weeks the scaffold had turned into human bone.

Source: infoniac.com