3D printing
Encyclopedia
3D printing is a form of additive manufacturing
technology where a three dimensional object is created by laying down successive layers of material. 3D printers are generally faster, more affordable, and easier to use than other additive manufacturing technologies. However, the term 3D printing is increasingly being used to describe all additive manufacturing processes. 3D printers offer product developers the ability to print parts and assemblies made of several materials with different mechanical and physical properties, often in a single build process. Advanced 3D printing technologies yield models that can serve as product prototypes
.
Since 2003 there has been large growth in the sale of 3D printers. Additionally, the cost of 3D printers has declined. The technology also finds use in the fields of jewelry, footwear, industrial design
, architecture, engineering and construction (AEC), automotive, aerospace, dental and medical industries, education, geographic information systems, civil engineering, and many others.
(SLS) and fused deposition modeling
(FDM), while others lay liquid materials that are cured with different technologies. In the case of laminated object manufacturing
, thin layers are cut to shape and joined together.
Each method has its advantages and drawbacks, and consequently some companies offer a choice between powder and polymer as the material from which the object emerges. Generally, the main considerations are speed, cost of the printed prototype, cost of the 3D printer, choice and cost of materials and colour capabilities.
One method of 3D printing consists of an inkjet printing
system. The printer creates the model one layer at a time by spreading a layer of powder (plaster
, or resin
s) and inkjet printing a binder in the cross-section of the part. The process is repeated until every layer is printed. This technology is the only one that allows for the printing of full colour prototypes. This method also allows overhangs.
In digital light processing (DLP), a vat of liquid polymer is exposed to light from a DLP projector under safelight
conditions. The exposed liquid polymer hardens. The build plate then moves down in small increments and the liquid polymer is again exposed to light. The process repeats until the model is built. The liquid polymer is then drained from the vat, leaving the solid model. The ZBuilder Ultra is an example of a DLP rapid prototyping system.
Fused deposition modeling
, a technology developed by Stratasys
that is used in traditional rapid prototyping, uses a nozzle to deposit molten polymer onto a support structure, layer by layer.
Another approach is selective fusing of print media in a granular bed. In this variation, the unfused media serves to support overhangs and thin walls in the part being produced, reducing the need for auxiliary temporary supports for the workpiece. Typically a laser is used to sinter
the media and form the solid. Examples of this are selective laser sintering and direct metal laser sintering
(DMLS) using metals.
Yet another approach uses a synthetic resin that is solidified using LED
s.
Finally, ultra-small features may be made by the 3D microfabrication technique of 2-photon
photopolymerization. In this approach, the desired 3D object is traced out in a block of gel by a focused laser. The gel is cured to a solid only in the places where the laser was focused, due to the nonlinear
nature of photoexcitation, and then the remaining gel is washed away. Feature sizes of under 100 nm are easily produced, as well as complex structures such as moving and interlocked parts.
Unlike stereolithography
, inkjet 3D printing is optimized for speed, low cost, and ease-of-use, making it suitable for visualizing during the conceptual stages of engineering design through to early-stage functional testing. No toxic chemicals like those used in stereolithography are required, and minimal post printing finish work is needed; one need only to use the printer itself to blow off surrounding powder after the printing process. Bonded powder prints can be further strengthened by wax or thermoset polymer impregnation. FDM parts can be strengthened by wicking another metal into the part.
. Typical layer thickness is around 100 micrometre
s (0.1 mm), although some machines such as the Objet Connex can print layers as thin as 16 micrometres. X-Y resolution is comparable to that of laser printers. The particles (3D dots) are around 50 to 100 micrometres (0.05-0.1 mm) in diameter.
Standard applications include design visualization, prototyping/CAD, metal casting, architecture, education, geospatial, healthcare and entertainment/retail. Other applications would include reconstructing fossils in paleontology
, replicating ancient and priceless artifacts in archaeology
, reconstructing bones and body parts in forensic pathology
and reconstructing heavily damaged evidence acquired from crime scene investigations.
More recently, the use of 3D printing technology for artistic expression has been suggested. Artists have been using 3D printers in various ways. During the 2011 London Design Festival, an installation, curated by Murray Moss and focused on 3D Printing, took place in the Victoria and Albert Museum (the V&A). The installation was called Industrial Revolution 2.0: How the Material World will Newly Materialise.
3D printing technology is currently being studied by biotechnology firms and academia for possible use in tissue engineering applications where organs and body parts are built using inkjet techniques. Layers of living cells are deposited onto a gel medium and slowly built up to form three dimensional structures. Several terms have been used to refer to this field of research: organ printing, bio-printing, and computer-aided tissue engineering
, among others. 3D printing can produce a personalized hip replacement in one pass, with the ball permanently inside the socket, and even at current printing resolutions the unit will not require polishing.
The use of 3D scanning technologies allow the replication of real objects without the use of molding
techniques, that in many cases can be more expensive, more difficult, or too invasive to be performed; particularly with precious or delicate cultural heritage artifacts where the direct contact of the molding substances could harm the surface of the original object.
, Stratasys
, 3D Systems
, EOS GmbH
, and Z Corporation
.
s. Much of this work was driven by and targeted to DIY
/enthusiast/early adopter communities, with links to both the academic and hacker communities.
RepRap is a project that aims to produce a FOSS
3D printer, whose full specifications are released under the GNU General Public License
, that can copy some part of itself (the printed parts). As of November 2010, the RepRap can only print plastic
parts. Research is under way to enable the device to print circuit boards too, as well as metal parts. The average price of a RepRap printer is about 400 euro (537 USD).
3D printer kits can also be obtained. Kits exist for Thing-O-Matic, Ultimaker, Shapercube, Mosaic, Prusa and Huxley 3D printers. Prices of these printer kits vary from 500 USD for the Printrbot derived from previous RepRap models, to $1800. The MakerBot is an open source
3D printer from MakerBot Industries
.
, Shapeways
, Sculpteo
, Ponoko
and i.materialise offer an on-line 3D printing service which is open to both consumers and industry. People upload their own 3D designs to the company website, designs are printed via industrial 3D printers and then shipped to the customer.
Additive manufacturing
Additive manufacturing is defined by ASTM as the "process of joining materials to make objects from 3D model data, usually layer upon layer, as opposed to subtractive manufacturing methodologies, such as traditional machining...
technology where a three dimensional object is created by laying down successive layers of material. 3D printers are generally faster, more affordable, and easier to use than other additive manufacturing technologies. However, the term 3D printing is increasingly being used to describe all additive manufacturing processes. 3D printers offer product developers the ability to print parts and assemblies made of several materials with different mechanical and physical properties, often in a single build process. Advanced 3D printing technologies yield models that can serve as product prototypes
Prototype
A prototype is an early sample or model built to test a concept or process or to act as a thing to be replicated or learned from.The word prototype derives from the Greek πρωτότυπον , "primitive form", neutral of πρωτότυπος , "original, primitive", from πρῶτος , "first" and τύπος ,...
.
Since 2003 there has been large growth in the sale of 3D printers. Additionally, the cost of 3D printers has declined. The technology also finds use in the fields of jewelry, footwear, industrial design
Industrial design
Industrial design is the use of a combination of applied art and applied science to improve the aesthetics, ergonomics, and usability of a product, but it may also be used to improve the product's marketability and production...
, architecture, engineering and construction (AEC), automotive, aerospace, dental and medical industries, education, geographic information systems, civil engineering, and many others.
Methods
A large number of competing technologies are available to do 3D printing. Their main differences are found in the way layers are built to create parts. Some methods use melting or softening material to produce the layers, e.g. selective laser sinteringSelective laser sintering
Selective laser sintering is an additive manufacturing technique that uses a high power laser to fuse small particles of plastic, metal , ceramic, or glass powders into a mass that has a desired 3-dimensional shape...
(SLS) and fused deposition modeling
Fused deposition modeling
Fused deposition modeling is an additive manufacturing technology commonly used for modeling, prototyping, and production applications. The technology was developed by S...
(FDM), while others lay liquid materials that are cured with different technologies. In the case of laminated object manufacturing
Laminated object manufacturing
Laminated object manufacturing is a rapid prototyping system developed by Helisys Inc. In it, layers of adhesive-coated paper, plastic, or metal laminates are successively glued together and cut to shape with a knife or laser cutter.The process is performed as follows:# Sheet is adhered to a...
, thin layers are cut to shape and joined together.
Each method has its advantages and drawbacks, and consequently some companies offer a choice between powder and polymer as the material from which the object emerges. Generally, the main considerations are speed, cost of the printed prototype, cost of the 3D printer, choice and cost of materials and colour capabilities.
One method of 3D printing consists of an inkjet printing
Inkjet printer
An inkjet printer is a type of computer printer that creates a digital image by propelling droplets of ink onto paper. Inkjet printers are the most commonly used type of printer and range from small inexpensive consumer models to very large professional machines that can cost up to thousands of...
system. The printer creates the model one layer at a time by spreading a layer of powder (plaster
Plaster
Plaster is a building material used for coating walls and ceilings. Plaster starts as a dry powder similar to mortar or cement and like those materials it is mixed with water to form a paste which liberates heat and then hardens. Unlike mortar and cement, plaster remains quite soft after setting,...
, or resin
Resin
Resin in the most specific use of the term is a hydrocarbon secretion of many plants, particularly coniferous trees. Resins are valued for their chemical properties and associated uses, such as the production of varnishes, adhesives, and food glazing agents; as an important source of raw materials...
s) and inkjet printing a binder in the cross-section of the part. The process is repeated until every layer is printed. This technology is the only one that allows for the printing of full colour prototypes. This method also allows overhangs.
In digital light processing (DLP), a vat of liquid polymer is exposed to light from a DLP projector under safelight
Safelight
A safelight is a light source suitable for use in a photographic darkroom. It provides illumination only from parts of the visible spectrum to which the photographic material in use is nearly or completely insensitive.- Design :...
conditions. The exposed liquid polymer hardens. The build plate then moves down in small increments and the liquid polymer is again exposed to light. The process repeats until the model is built. The liquid polymer is then drained from the vat, leaving the solid model. The ZBuilder Ultra is an example of a DLP rapid prototyping system.
Fused deposition modeling
Fused deposition modeling
Fused deposition modeling is an additive manufacturing technology commonly used for modeling, prototyping, and production applications. The technology was developed by S...
, a technology developed by Stratasys
Stratasys
Stratasys, Inc. , founded by S. Scott Crump and his wife Lisa Crump, is a company that manufactures additive fabrication machines for direct digital manufacturing , 3D printing and rapid prototyping...
that is used in traditional rapid prototyping, uses a nozzle to deposit molten polymer onto a support structure, layer by layer.
Another approach is selective fusing of print media in a granular bed. In this variation, the unfused media serves to support overhangs and thin walls in the part being produced, reducing the need for auxiliary temporary supports for the workpiece. Typically a laser is used to sinter
Sintering
Sintering is a method used to create objects from powders. It is based on atomic diffusion. Diffusion occurs in any material above absolute zero, but it occurs much faster at higher temperatures. In most sintering processes, the powdered material is held in a mold and then heated to a temperature...
the media and form the solid. Examples of this are selective laser sintering and direct metal laser sintering
Direct metal laser sintering
Direct metal laser sintering is an additive metal fabrication technology developed by EOS out of Munich, Germany, sometimes also referred to by the terms selective laser sintering or selective laser melting . The process involves use of a 3D CAD model whereby a .stl file is created and sent to...
(DMLS) using metals.
Yet another approach uses a synthetic resin that is solidified using LED
LEd
LEd is a TeX/LaTeX editing software working under Microsoft Windows. It is a freeware product....
s.
Finally, ultra-small features may be made by the 3D microfabrication technique of 2-photon
Two-photon absorption
Two-photon absorption is the simultaneous absorption of two photons of identical or different frequencies in order to excite a molecule from one state to a higher energy electronic state. The energy difference between the involved lower and upper states of the molecule is equal to the sum of the...
photopolymerization. In this approach, the desired 3D object is traced out in a block of gel by a focused laser. The gel is cured to a solid only in the places where the laser was focused, due to the nonlinear
Nonlinear optics
Nonlinear optics is the branch of optics that describes the behavior of light in nonlinear media, that is, media in which the dielectric polarization P responds nonlinearly to the electric field E of the light...
nature of photoexcitation, and then the remaining gel is washed away. Feature sizes of under 100 nm are easily produced, as well as complex structures such as moving and interlocked parts.
Unlike stereolithography
Stereolithography
Stereolithography is an additive manufacturing technology for producing models, prototypes, patterns, and in some cases, production parts.-Technology description:...
, inkjet 3D printing is optimized for speed, low cost, and ease-of-use, making it suitable for visualizing during the conceptual stages of engineering design through to early-stage functional testing. No toxic chemicals like those used in stereolithography are required, and minimal post printing finish work is needed; one need only to use the printer itself to blow off surrounding powder after the printing process. Bonded powder prints can be further strengthened by wax or thermoset polymer impregnation. FDM parts can be strengthened by wicking another metal into the part.
Resolution
Resolution is given in layer thickness and X-Y resolution in dpiDots per inch
Dots per inch is a measure of spatial printing or video dot density, in particular the number of individual dots that can be placed in a line within the span of 1 inch . The DPI value tends to correlate with image resolution, but is related only indirectly.- DPI measurement in monitor...
. Typical layer thickness is around 100 micrometre
Micrometre
A micrometer , is by definition 1×10-6 of a meter .In plain English, it means one-millionth of a meter . Its unit symbol in the International System of Units is μm...
s (0.1 mm), although some machines such as the Objet Connex can print layers as thin as 16 micrometres. X-Y resolution is comparable to that of laser printers. The particles (3D dots) are around 50 to 100 micrometres (0.05-0.1 mm) in diameter.
Applications
Paleontology
Paleontology "old, ancient", ὄν, ὀντ- "being, creature", and λόγος "speech, thought") is the study of prehistoric life. It includes the study of fossils to determine organisms' evolution and interactions with each other and their environments...
, replicating ancient and priceless artifacts in archaeology
Archaeology
Archaeology, or archeology , is the study of human society, primarily through the recovery and analysis of the material culture and environmental data that they have left behind, which includes artifacts, architecture, biofacts and cultural landscapes...
, reconstructing bones and body parts in forensic pathology
Pathology
Pathology is the precise study and diagnosis of disease. The word pathology is from Ancient Greek , pathos, "feeling, suffering"; and , -logia, "the study of". Pathologization, to pathologize, refers to the process of defining a condition or behavior as pathological, e.g. pathological gambling....
and reconstructing heavily damaged evidence acquired from crime scene investigations.
More recently, the use of 3D printing technology for artistic expression has been suggested. Artists have been using 3D printers in various ways. During the 2011 London Design Festival, an installation, curated by Murray Moss and focused on 3D Printing, took place in the Victoria and Albert Museum (the V&A). The installation was called Industrial Revolution 2.0: How the Material World will Newly Materialise.
3D printing technology is currently being studied by biotechnology firms and academia for possible use in tissue engineering applications where organs and body parts are built using inkjet techniques. Layers of living cells are deposited onto a gel medium and slowly built up to form three dimensional structures. Several terms have been used to refer to this field of research: organ printing, bio-printing, and computer-aided tissue engineering
Tissue engineering
Tissue engineering is the use of a combination of cells, engineering and materials methods, and suitable biochemical and physio-chemical factors to improve or replace biological functions...
, among others. 3D printing can produce a personalized hip replacement in one pass, with the ball permanently inside the socket, and even at current printing resolutions the unit will not require polishing.
The use of 3D scanning technologies allow the replication of real objects without the use of molding
Molding (process)
Molding or moulding is the process of manufacturing by shaping pliable raw material using a rigid frame or model called a pattern....
techniques, that in many cases can be more expensive, more difficult, or too invasive to be performed; particularly with precious or delicate cultural heritage artifacts where the direct contact of the molding substances could harm the surface of the original object.
Industrial use
Industrial 3D printers are made by companies such as Objet GeometriesObjet Geometries
Objet Geometries Ltd is engaged in the design, development and manufacture of photopolymer 3D printing systems. The company is based in Rehovot, Israel and was incorporated in 1999...
, Stratasys
Stratasys
Stratasys, Inc. , founded by S. Scott Crump and his wife Lisa Crump, is a company that manufactures additive fabrication machines for direct digital manufacturing , 3D printing and rapid prototyping...
, 3D Systems
3D Systems
3D Systems, headquartered in Rock Hill, South Carolina, is a maker of rapid prototyping machines, notable for developing stereolithography and the STL file format.- History :...
, EOS GmbH
EOS (company)
EOS GmbH, or EOS, Electro Optical Systems, is a major manufacturer of SLS and DMLS laser sintering systems, based in Krailling, Germany. Its revenues exceed 60 million Euros, and employs 300 people worldwide...
, and Z Corporation
Z Corporation
Z Corporation is a manufacturer of 3D printers capable of printing multicolored parts, rapid prototyping machines that build plastic prototypes and 3D scanners. Z Corporation is headquartered in Burlington, Massachusetts, USA.The company name relates to the z axis which adds depth to the other 2...
.
Domestic use
There have been several, often related, efforts to develop 3D printers suitable for desktop use, and to make this technology available at price points affordable to many individual end-userEnd-user
Economics and commerce define an end user as the person who uses a product. The end user or consumer may differ from the person who purchases the product...
s. Much of this work was driven by and targeted to DIY
Do it yourself
Do it yourself is a term used to describe building, modifying, or repairing of something without the aid of experts or professionals...
/enthusiast/early adopter communities, with links to both the academic and hacker communities.
RepRap is a project that aims to produce a FOSS
Free and open source software
Free and open-source software or free/libre/open-source software is software that is liberally licensed to grant users the right to use, study, change, and improve its design through the availability of its source code...
3D printer, whose full specifications are released under the GNU General Public License
GNU General Public License
The GNU General Public License is the most widely used free software license, originally written by Richard Stallman for the GNU Project....
, that can copy some part of itself (the printed parts). As of November 2010, the RepRap can only print plastic
Plastic
A plastic material is any of a wide range of synthetic or semi-synthetic organic solids used in the manufacture of industrial products. Plastics are typically polymers of high molecular mass, and may contain other substances to improve performance and/or reduce production costs...
parts. Research is under way to enable the device to print circuit boards too, as well as metal parts. The average price of a RepRap printer is about 400 euro (537 USD).
3D printer kits can also be obtained. Kits exist for Thing-O-Matic, Ultimaker, Shapercube, Mosaic, Prusa and Huxley 3D printers. Prices of these printer kits vary from 500 USD for the Printrbot derived from previous RepRap models, to $1800. The MakerBot is an open source
Open source
The term open source describes practices in production and development that promote access to the end product's source materials. Some consider open source a philosophy, others consider it a pragmatic methodology...
3D printer from MakerBot Industries
MakerBot Industries
MakerBot Industries is a Brooklyn, New York-based company founded in January 2009 by Bre Pettis, Adam Mayer, and Zach "Hoeken" Smith producing open source hardware, specifically 3D printers...
.
Vendors and services
Some companies such as KraftwurxKraftwurx
Kraftwurx is a company specializing in 3D printing. The company offers three services: Users can upload 3D models and kraftwurx prints them. Models uploaded are made available for sale to others...
, Shapeways
Shapeways
Shapeways is a 3D printing service. Users upload design files and Shapeways prints the objects for them or others. Users can have objects printed from a variety of materials, including food safe ceramics....
, Sculpteo
Sculpteo
Sculpteo is a French company specialized in 3D printing. Sculpteo offers an online 3D printing service , using rapid prototyping and a manufacturing process involving laser sintering or stereo lithography . The company was founded in June 2009 by Eric Carreel co-founder of Inventel , acquired by...
, Ponoko
Ponoko
Ponoko is an online service for manufacturing. It gained some considerable media attention because of its unique business model. Ponoko is one of the first manufacturers that uses distributed manufacturing and on-demand manufacturing.-Distribution Model:...
and i.materialise offer an on-line 3D printing service which is open to both consumers and industry. People upload their own 3D designs to the company website, designs are printed via industrial 3D printers and then shipped to the customer.
See also
- Additive Manufacturing File FormatAdditive Manufacturing File FormatAdditive Manufacturing File Format is an open standard for describing objects for additive manufacturing processes such as 3D printing. The official ASTM F2915standard is an XML-based format designed to allow any computer-aided design software to describe the shape and composition of any 3D object...
- List of emerging technologies
- Self-replicating machineSelf-replicating machineA self-replicating machine is an artificial construct that is theoretically capable of autonomously manufacturing a copy of itself using raw materials taken from its environment, thus exhibiting self-replication in a way analogous to that found in nature. The concept of self-replicating machines...
Further reading
- Wright, Paul K. (2001). 21st Century manufacturing. New Jersey: Prentice-Hall Inc.
External links
- New Dimension 3D Printing Machines
- 3D Printing, The Next Napster?
- New York Times: 3-D Printing Spurs a Manufacturing Revolution
- Times Online article - Microtrends: 3D Printing
- 3D printer reshapes world of copying
- 3D Printing for the Masses
- 'Gadget printer' promises industrial revolution New Scientist
- A Factory on Your Desk
- 3D Printing: The Printed World from The EconomistThe EconomistThe Economist is an English-language weekly news and international affairs publication owned by The Economist Newspaper Ltd. and edited in offices in the City of Westminster, London, England. Continuous publication began under founder James Wilson in September 1843...
- What is 3D printing? A beginners guide to the desktop factory
- EADS Airbike made of steel-strength nylon