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| HISTORY OF 3D PRINTING |
The history of
3D printing, also known as additive manufacturing, dates back several decades and
has seen significant advancements over time. Here's a brief overview of its history:
- 1960s-1980s: Early Conceptualization
and Development
- The concept of 3D printing began
to take shape in the 1960s with the development of various techniques like
stereolithography and digital light processing (DLP).
- In 1984, Chuck Hull introduced stereolithography,
which involved using UV light to selectively cure liquid photopolymers layer
by layer. This is considered one of the earliest additive manufacturing technologies.
- 1980s-1990s: Emerging Technologies
- In the late 1980s and early 1990s,
several other additive manufacturing methods were developed, including selective
laser sintering (SLS) and fused deposition modeling (FDM).
- In 1992, Carl Deckard developed
selective laser sintering (SLS), a process that involves using a high-powered
laser to selectively fuse powdered materials into a solid structure layer
by layer.
- In 1989, Scott Crump patented the
fused deposition modeling (FDM) process, which extrudes thermoplastic materials
layer by layer to create objects.
- The 2000s: Expansion and Commercialization
- The 2000s saw the expansion of 3D
printing technologies into various industries, including aerospace, automotive,
healthcare, and more.
- Advanced materials beyond plastics,
such as metals and ceramics, began to be used in additive manufacturing.
- Companies like Stratasys and 3D
Systems played pivotal roles in advancing 3D printing technologies and making
them more accessible.
- The 2010s: Mainstream Adoption and Diversification
- The 2010s marked a period of rapid
growth in 3D printing technology adoption, with increased accessibility to
lower-cost printers for businesses and even consumers.
- Industries like healthcare started
using 3D printing for custom medical implants, prosthetics, and even organ
and tissue printing.
- Aerospace and automotive industries
embraced 3D printing for rapid prototyping and production of complex parts.
- Recent Developments and Future Prospects
- In recent years, 3D printing has
continued to evolve with advancements in materials, printing speed, precision,
and the scale of objects that can be printed.
- Large-scale 3D printing and construction
have gained attention for their potential to revolutionize building techniques.
- Bioprinting, the process of creating
living tissues and organs using 3D printing technology, has shown promising
developments in medical and research fields.
Overall, the
history of 3D printing showcases a trajectory of innovation and increasing application
across various industries, making it a transformative technology with a wide range
of possibilities for the future.
3D printing
A three-dimensional printer
3D printing or additive manufacturing is the
construction of a three-dimensional object from a CAD model or a digital 3D model.
It can be done in a variety of processes in which material is deposited, joined, or solidified under computer control, with the material being added together (such as
plastics, liquids, or powder grains being fused), typically layer by layer.
In the 1980s, 3D printing techniques were
considered suitable only for the production of functional or aesthetic prototypes,
and a more appropriate term for it at the time was rapid prototyping. As of 2019,
the precision, repeatability, and material range of 3D printing has increased to
the point that some 3D printing processes are considered viable as an industrial-production
technology, whereby the term additive manufacturing can be used synonymously
with 3D printing. One of the key advantages of 3D printing is the ability
to produce very complex shapes or geometries that would be otherwise infeasible
to construct by hand, including hollow parts or parts with internal truss structures
to reduce weight. Fused deposition modeling (FDM), which uses a continuous filament
of a thermoplastic material, is the most common 3D printing process in use as of
2020.
Terminology
The umbrella term additive manufacturing
(AM) gained popularity in the 2000s, inspired by the theme of materials being
added together (in various ways). In contrast, the term subtractive manufacturing
appeared as a retronym for the large family of machining processes with material
removal as their common process. The term 3D printing still referred
only to the polymer technologies in most minds, and the term AM was more
likely to be used in metalworking and end-use part production contexts than among
polymer, inkjet, or stereolithography enthusiasts.
By the early 2010s, the terms 3D printing
and additive manufacturing evolved senses in which they were alternate umbrella
terms for additive technologies, one being used in popular language by consumer-maker
communities and the media, and the other used more formally by industrial end-use
part producers, machine manufacturers, and global technical standards organizations.
Until recently, the term 3D printing has been associated with machines low
in price or in capability. 3D printing and additive manufacturing
reflect that the technologies share the theme of material addition or joining throughout
a 3D work envelope under automated control. Peter Zelinski, the editor-in-chief
of Additive Manufacturing magazine, pointed out in 2017 that the terms are
still often synonymous in casual usage, but some manufacturing industry experts
are trying to make a distinction whereby additive manufacturing comprises 3D printing
plus other technologies or other aspects of a manufacturing process.
Other terms that have been used as synonyms
or hypernyms have included desktop manufacturing, rapid manufacturing
(as the logical production-level successor to rapid prototyping), and on-demand
manufacturing (which echoes on-demand printing in the 2D sense of printing).
The fact that the application of the adjectives rapid and on-demand
to noun manufacturing was novel in the 2000s reveals the long-prevailing
mental model of the previous industrial era during which almost all production manufacturing
had involved long lead times for laborious tooling development. Today, the term
subtractive has not replaced the term machining, instead complementing
it when a term that covers any removal method is needed. Agile tooling is the use
of modular means to design tooling that is produced by additive manufacturing or
3D printing methods to enable quick prototyping and responses to tooling and fixture
needs. Agile tooling uses a cost-effective and high-quality method to quickly respond
to customer and market needs, and it can be used in hydro-forming, stamping, injection
molding, and other manufacturing processes.
History
1940s and 1950s
The general concept of and procedure to
be used in 3D printing was first described by Murray Leinster in his 1945 short
story “Things Pass By”: "But this constructor is both efficient and flexible.
I feed magnetron plastics - the stuff they make houses and ships of nowadays -
into this moving arm. It makes drawings in the air following drawings it scans with photocells. But plastic comes out of the end of the drawing arm and hardens as
it comes ... following drawings only"
It was also described by Raymond F. Jones
in his story, "Tools of the Trade," published in the November 1950 issue
of Astounding Science Fiction magazine. He referred to it as a "molecular
spray" in that story.
1970s
In 1971, Johannes F Gottwald patented the
Liquid Metal Recorder, U.S. Patent 3596285A, a continuous inkjet metal material
device to form a removable metal fabrication on a reusable surface for immediate
use or salvaged for printing again by remelting. This appears to be the first patent
describing 3D printing with rapid prototyping and controlled on-demand manufacturing
of patterns.
The patent states:
As used herein the
term printing is not intended in a limited sense but includes writing or other symbols,
character, or pattern formation with an ink. The term ink as used is intended
to include not only dye or pigment-containing materials, but any flowable substance
or composition suited for application to the surface for forming symbols, characters,
or patterns of intelligence by marking. The preferred ink is of a hot melt type.
The range of commercially available ink compositions which could meet the requirements
of the invention is not known at the present time. However, satisfactory printing
according to the invention has been achieved with the conductive metal alloy as
ink.
But in terms of material requirements for
such large and continuous displays, if consumed at theretofore known rates, but
increased in proportion to increase in size, the high cost would severely limit
any widespread enjoyment of a process or apparatus satisfying the foregoing objects.
It is therefore an additional object of
the invention to minimize the use of materials in a process of the indicated class.
It is a further object of the invention
that materials employed in such a process be salvaged for reuse.
According to another aspect of the invention,
a combination of writing and the like comprises a carrier for displaying an intelligence
pattern and an arrangement for removing the pattern from the carrier.
In 1974, David E. H. Jones laid out the
concept of 3D printing in his regular column Ariadne in the journal New
Scientist.
1980s
Early additive manufacturing equipment and
materials were developed in the 1980s.
In April 1980, Hideo Kodama of Nagoya Municipal
Industrial Research Institute invented two additive methods for fabricating three-dimensional
plastic models with photo-hardening thermoset polymer, where the UV exposure area
is controlled by a mask pattern or a scanning fiber transmitter. He filed a patent
for this XYZ plotter, which was published on 10 November 1981. (JP S56-144478).
His research results as journal papers were published in April and November of 1981.
However, there was no reaction to the series of his publications. His device was
not highly evaluated in the laboratory and his boss did not show any interest. His
research budget was just 60,000 yen or $545 a year. Acquiring the patent rights
for the XYZ plotter was abandoned, and the project was terminated.
A US 4323756 patent, method of fabricating
articles by sequential deposition, granted on 6 April 1982 to Raytheon Technologies
Corp describes using hundreds or thousands of "layers" of powdered metal
and a laser energy source and represents an early reference to forming "layers"
and the fabrication of articles on a substrate.
On 2 July 1984, American entrepreneur Bill
Masters filed a patent for his computer automated manufacturing process and system
(US 4665492). This filing is on record at the USPTO as the first 3D printing patent
in history; it was the first of three patents belonging to Masters that laid the
foundation for the 3D printing systems used today.
On 16 July 1984, Alain Le Méhauté, Olivier
de Witte, and Jean Claude André filed their patent for the stereolithography process.
The application of the French inventors was abandoned by the French General Electric
Company (now Alcatel-Alsthom) and CILAS (The Laser Consortium). The claimed reason
was "for lack of business perspective".
In 1983, Robert Howard started R.H. Research,
later named Howtek, Inc. in Feb 1984 to develop a color inkjet 2D printer, Pixelmaster,
commercialized in 1986, using Thermoplastic (hot-melt) plastic ink. A team was put
together, 6 members from Exxon Office Systems, Danbury Systems Division, an inkjet
printer startup, and some members of the Howtek, Inc group who became popular figures
in the 3D printing industry. One Howtek member, Richard Helinski (patent US5136515A,
Method and Means for constructing three-dimensional articles by particle deposition,
application 11/07/1989 granted 8/04/1992) formed a New Hampshire company C.A.D-Cast,
Inc, a name later changed to Visual Impact Corporation (VIC) on 8/22/1991. A prototype
of the VIC 3D printer for this company is available with a video presentation showing
a 3D model printed with a single nozzle inkjet. Another employee Herbert Menhennett
formed a New Hampshire company HM Research in 1991 and introduced the Howtek, Inc,
inkjet technology and thermoplastic materials to Royden Sanders of SDI and Bill
Masters of Ballistic Particle Manufacturing (BPM) where he worked for a number of
years. Both BPM 3D printers and SPI 3D printers use Howtek, Inc style Inkjets and
Howtek, Inc style materials. Royden Sanders licensed the Helinksi patent prior to
manufacturing the Modelmaker 6 Pro at Sanders Prototype, Inc (SPI) in 1993. James
K. McMahon who was hired by Howtek, Inc to help develop the inkjet, later worked
at Sanders Prototype and now operates Layer Grown Model Technology, a 3D service
provider specializing in Howtek single nozzle inkjet and SDI printer support. James
K. McMahon worked with Steven Zoltan, a 1972 drop-on-demand inkjet inventor, at Exxon
and has a patent in 1978 that expanded the understanding of the single nozzle design
inkjets (Alpha jets) and help perfect the Howtek, Inc hot-melt inkjets. This Howtek
hot-melt thermoplastic technology is popular with metal investment casting, especially
in the 3D printing jewelry industry. Sanders's (SDI) first Modelmaker 6Pro customer
was Hitchner Corporations, Metal Casting Technology, Inc in Milford, NH a mile from
the SDI facility in late 1993-1995 casting golf clubs and auto engine parts.
On 8 August 1984 a patent, US4575330, assigned
to UVP, Inc., later assigned to Chuck Hull of 3D Systems Corporation was filed,
his own patent for a stereolithography fabrication system, in which individual laminae
or layers are added by curing photopolymers with impinging radiation, particle bombardment,
chemical reaction or just ultraviolet light lasers. Hull defined the process as
a "system for generating three-dimensional objects by creating a cross-sectional
pattern of the object to be formed". Hull's contribution was the STL (Stereolithography)
file format and the digital slicing and infill strategies common to many processes
today. In 1986, Charles "Chuck" Hull was granted a patent for this system,
and his company, 3D Systems Corporation was formed and it released the first commercial
3D printer, the SLA-1, later in 1987 or 1988.
The technology used by most 3D printers
to date-especially hobbyist and consumer-oriented models-is fused deposition modeling,
a special application of plastic extrusion, developed in 1988 by S. Scott Crump
and commercialized by his company Stratasys, which marketed its first FDM machine
in 1992.
Owning a 3D printer in the 1980s cost upwards
of $300,000 ($650,000 in 2016 dollars).
1990s
AM processes for metal sintering or melting
(such as selective laser sintering, direct metal laser sintering, and selective
laser melting) usually went by their own individual names in the 1980s and 1990s.
At the time, all metalworking was done by processes that are now called non-additive
(casting, fabrication, stamping, and machining); although plenty of automation was
applied to those technologies (such as by robot welding and CNC), the idea of a
tool or head moving through a 3D work envelope transforming a mass of raw material
into a desired shape with a toolpath was associated in metalworking only with processes
that removed metal (rather than adding it), such as CNC milling, CNC EDM, and many
others. But the automated techniques that added metal, which would later
be called additive manufacturing, were beginning to challenge that assumption. By
the mid-1990s, new techniques for material deposition were developed at Stanford
and Carnegie Mellon University, including micro casting and sprayed materials.[33]
Sacrificial and support materials had also become more common, enabling new object
geometries.
The term 3D printing originally referred
to a powder bed process employing standard and custom inkjet print heads, developed
at MIT by Emanuel Sachs in 1993 and commercialized by Soligen Technologies, Extrude
Hone Corporation, and Z Corporation.
The year 1993 also saw the start of an inkjet
3D printer company initially named Sanders Prototype, Inc and later named Solidscape,
introducing a high-precision polymer jet fabrication system with soluble support
structures, (categorized as a "dot-on-dot" technique).
In 1995 the Fraunhofer Society developed
the selective laser melting process.
2000s
The Fused Deposition Modeling (FDM) printing
process patents expired in 2009. This opened the door for a new wave of companies,
many born from the RepRap community, to start developing commercial FDM 3D printers.
2010s
As the various additive processes matured,
it became clear that soon metal removal would no longer be the only metalworking
process done through a tool or head moving through a 3D work envelope, transforming
a mass of raw material into a desired shape layer by layer. The 2010s were the first
decade in which metal end-use parts such as engine brackets and large nuts would
be grown (either before or instead of machining) in job production rather than obligately
being machined from bar stock or plate. It is still the case that casting, fabrication,
stamping, and machining are more prevalent than additive manufacturing in metalworking,
but AM is now beginning to make significant inroads, and with the advantages of
design for additive manufacturing, it is clear to engineers that much more is to
come.
One place that AM is making significant
inroads is in the aviation industry. With nearly 3.8 billion air travelers in 2016,
the demand for fuel-efficient and easily produced jet engines has never been higher.
For large OEMs (original equipment manufacturers) like Pratt and Whitney (PW) and
General Electric (GE), this means looking towards AM as a way to reduce cost, reduce
the number of nonconforming parts, reduce weight in the engines to increase fuel
efficiency and find new, highly complex shapes that would not be feasible with the
antiquated manufacturing methods. One example of AM integration with aerospace was
in 2016 when Airbus delivered the first of GE's LEAP engines. This engine has
integrated 3D printed fuel nozzles giving them a reduction in parts from 20 to 1,
a 25% weight reduction, and reduced assembly times. A fuel nozzle is the perfect road for additive manufacturing in a jet engine since it allows for optimized
design of the complex internals and it is a low-stress, non-rotating part. Similarly,
in 2015, PW delivered their first AM parts in the PurePower PW1500G to Bombardier.
Sticking to low-stress, non-rotating parts, PW selected the compressor stators and
synch ring brackets to roll out this new manufacturing technology for the first
time. While AM is still playing a small role in the total number of parts in the
jet engine manufacturing process, the return on investment can already be seen by
the reduction in parts, the rapid production capabilities, and the "optimized
design in terms of performance and cost".
As the technology matured, several authors had
begun to speculate that 3D printing could aid in sustainable development in the
developing world.
In 2012, Filabot developed a system for
closing the loop with plastic and allows for any FDM or FFF 3D printer to be able
to print with a wider range of plastics.
In 2014, Benjamin S. Cook and Manos M. Tentzeris
demonstrate the first multi-material, vertically integrated printed electronics
additive manufacturing platform (VIPRE) which enabled 3D printing of functional
electronics operating up to 40 GHz.
As the price of printers started to drop
people interested in this technology had more access and freedom to make what they
wanted. As of 2014, the price for commercial printers was still high with the cost
being over $2,000.
The term "3D printing" originally
referred to a process that deposits a binder material onto a powder bed with inkjet
printer heads layer by layer. More recently, the popular vernacular has started
using the term to encompass a wider variety of additive-manufacturing techniques
such as electron-beam additive manufacturing and selective laser melting. The United
States and global technical standards use the official term additive manufacturing
for this broader sense.
The most commonly used 3D printing process
(46% as of 2018) is a material extrusion technique called fused deposition modeling,
or FDM. While FDM technology was invented after the other two most popular technologies,
stereolithography (SLA) and selective laser sintering (SLS), FDM is typically the
most inexpensive of the three by a large margin, which lends to the popularity of
the process.
2020s
As of 2020, 3D printers have reached the
level of quality and price that allows most people to enter the world of 3D printing.
In 2020 decent-quality printers can be found for less than US$200 for entry-level
machines. These more affordable printers are usually fused deposition modeling (FDM)
printers.
In November 2021 a British patient named
Steve Verze received the world's first fully 3D-printed prosthetic eye from the
Moorfields Eye Hospital in London.
Benefits of 3D printing
Additive manufacturing or 3D printing has
rapidly gained importance in the field of engineering due to its many benefits.
Some of these benefits include enabling faster prototyping, reducing manufacturing
costs, increasing product customization, and improving product quality.
Furthermore, the capabilities of 3D printing
have extended beyond traditional manufacturing, with applications in renewable energy
systems. 3D printing technology can be used to produce battery energy storage systems,
which are essential for sustainable energy generation and distribution.
Another benefit of 3D printing is the technology's
ability to produce complex geometries with high precision and accuracy. This is
particularly relevant in the field of microwave engineering, where 3D printing can
be used to produce components with unique properties that are difficult to achieve
using traditional manufacturing methods.
General principles
Modeling
CAD model used for 3D printing
3D models can be generated from 2D pictures taken at a 3D photo booth.
3D printable models may be created with
a computer-aided design (CAD) package, via a 3D scanner, or by a plain digital camera
and photogrammetry software. 3D printed models created with CAD result in relatively
fewer errors than other methods. Errors in 3D printable models can be identified
and corrected before printing. The manual modeling process of preparing geometric
data for 3D computer graphics is similar to plastic arts such as sculpting. 3D scanning
is a process of collecting digital data on the shape and appearance of a real object and creating a digital model based on it.
CAD models can be saved in the stereolithography
file format (STL), a de facto CAD file format for additive manufacturing that stores
data based on triangulations of the surface of CAD models. STL is not tailored for
additive manufacturing because it generates large file sizes of topology-optimized
parts and lattice structures due to the large number of surfaces involved. A newer
CAD file format, the Additive Manufacturing File Format (AMF) was introduced in
2011 to solve this problem. It stores information using curved triangulations.
Printing
Before printing a 3D model from an STL file,
it must first be examined for errors. Most CAD applications produce errors in output
STL files, of the following types:
1. holes
2. faces normals
3. self-intersections
4. noise shells
5. manifold errors
6. overhang issues
A step in the STL generation known as "repair"
fixes such problems in the original model. Generally, STLs that have been produced
from a model obtained through 3D scanning often have more of these errors as 3D scanning is often achieved by point-to-point
acquisition/mapping. 3D reconstruction often includes errors.
Once completed, the STL file needs to be
processed by a piece of software called a "slicer", which converts the
model into a series of thin layers and produces a G-code file containing instructions
tailored to a specific type of 3D printer (FDM printers). This G-code file can then
be printed with 3D printing client software (which loads the G-code and uses it
to instruct the 3D printer during the 3D printing process).
Printer resolution describes layer thickness
and X–Y resolution in dots per inch (dpi) or micrometers (μm). Typical layer thickness
is around 100 μm (250 DPI), although some machines can print layers as thin as 16
μm (1,600 DPI). X-Y resolution is comparable to that of laser printers. The particles
(3D dots) are around 0.01 to 0.1 μm (2,540,000 to 250,000 DPI) in diameter. For
that printer resolution, specifying a mesh resolution of 0.01–0.03 mm and a chord
length ≤ 0.016 mm generates an optimal STL output file for a given model input file.
Specifying higher resolution results in larger files without an increase in print quality.
3:31 Timelapse of
an 80-minute video of an object being made out of PLA using molten polymer deposition
Construction of a model with contemporary
methods can take anywhere from several hours to several days, depending on the method
used and the size and complexity of the model. Additive systems can typically reduce
this time to a few hours, although it varies widely depending on the type of machine
used and the size and number of models being produced simultaneously.
Finishing
Though the printer-produced resolution and
surface finish are sufficient for some applications, post-processing and finishing
methods allow for benefits such as greater dimensional accuracy, smoother surfaces, and other modifications such as coloration.
The surface finish of a 3D printed part can be improved using subtractive methods such as sanding and bead blasting. When smoothing
parts that require dimensional accuracy, it is important to take into account the
volume of the material being removed.
Some printable polymers, such as acrylonitrile
butadiene styrene (ABS), allow the surface finish to be smoothed and improved using
chemical vapor processes based on acetone or similar solvents.
Some additive manufacturing techniques can
benefit from annealing annealing as a post-processing step. Annealing a 3D-printed
part allows for better internal layer bonding due to the recrystallization of the part
and allows for an increase in mechanical properties, some of which are fracture
toughness, flexural strength, impact resistance, and heat resistance. Annealing
a component may not be suitable for applications where dimensional accuracy is required,
as it can introduce warpage or shrinkage due to heating and cooling.
Additive/Subtractive Hybrid Manufacturing
(ASHM) is a method that involves producing a 3D printed part and using machining
(subtractive manufacturing) to remove material. Machining operations can be completed
after each layer, or after the entire 3D print has been completed depending on the
application requirements. These hybrid methods allow for 3D-printed parts to achieve
better surface finishes and dimensional accuracy.
The layered structure of traditional additive
manufacturing processes leads to a stair-stepping effect on part surfaces that
are curved or tilted with respect to the building platform. The effect strongly depends
on the layer height used, as well as the orientation of a part surface inside the
building process. This effect can be minimized using "variable layer heights"
or "adaptive layer heights". These methods decreased the layer height
in places where higher quality is needed.
Painting a 3D-printed part offers a range
of finishes and appearances that may not be achievable through most 3D printing
techniques. The process typically involves several steps such as surface preparation,
priming, and painting. These steps help prepare the surface of the part and ensure
the paint adheres properly.
Some additive manufacturing techniques are
capable of using multiple materials simultaneously. These techniques are able to
print in multiple colors and color combinations simultaneously and can produce
parts that may not necessarily require painting.
Some printing techniques require internal
supports to be built to support overhanging features during construction. These
supports must be mechanically removed or dissolved if using a water-soluble support
material such as PVA using after completing a print.
Some commercial metal 3D printers involve
cutting the metal component off the metal substrate after deposition. A new process
for GMAW 3D printing allows for substrate surface modifications to remove aluminum
or steel.
Multi-material 3D
printing
A multi-material 3DBenchy.
Efforts to achieve multi-material 3D printing
range from enhanced FDM-like processes like VoxelJet to novel voxel-based printing
technologies like layered assembly.
A drawback of many existing 3D printing
technologies is that they only allow one material to be printed at a time, limiting
many potential applications which require the integration of different materials
in the same object. Multi-material 3D printing solves this problem by allowing objects
of complex and heterogeneous arrangements of materials to be manufactured using
a single printer. Here, a material must be specified for each voxel (or 3D printing
pixel element) inside the final object volume.
The process can be fraught with complications,
however, due to the isolated and monolithic algorithms. Some commercial devices
have sought to solve these issues, such as building a Spec2Fab translator, but the
progress is still very limited. Nonetheless, in the medical industry, the concept
of 3D-printed pills and vaccines has been presented. With this new concept, multiple
medications can be combined, which will decrease many risks. With more and more
applications of multi-material 3D printing, the costs of daily life and high technology
development will become inevitably lower.
Metallographic materials of 3D printing
are also being researched. By classifying each material, CIMP-3D can systematically
perform 3D printing with multiple materials.
4D printing
Using 3D printing and multi-material structures
in additive manufacturing has allowed for the design and creation of what is called
4D printing. 4D printing is an additive manufacturing process in which the printed
object changes shape with time, temperature, or some other type of stimulation.
4D printing allows for the creation of dynamic structures with adjustable shapes,
properties, or functionality. The smart/stimulus-responsive materials that are created
using 4D printing can be activated to create calculated responses such as self-assembly,
self-repair, multi-functionality, reconfiguration, and shape-shifting. This allows
for customized printing of shape-changing and shape-memory materials.
4D printing has the potential to find new
applications and uses for materials (plastics, composites, metals, etc.) and will
create new alloys and composites that were not viable before. The versatility of
this technology and materials can lead to advances in multiple fields of industry,
including space, commercial, and the medical field. The repeatability, precision,
and material range for 4D printing must increase to allow the process to become
more practical throughout these industries.
To become a viable industrial production
option, there are a couple of challenges that 4D printing must overcome. The challenges
of 4D printing include the fact that the microstructures of these printed smart
materials must be close to or better than the parts obtained through traditional
machining processes. New and customizable materials need to be developed that have
the ability to consistently respond to varying external stimuli and change to their
desired shape. There is also a need to design new software for the various technique
types of 4D printing. The 4D printing software will need to take into consideration
the base smart material, printing technique, and structural and geometric requirements
of the design.
Applications
3D printing or additive manufacturing has
been used in manufacturing, medical, industry, and sociocultural sectors (e.g. Cultural
Heritage) to create successful commercial technology. More recently, 3D printing
has also been used in the humanitarian and development sector to produce a range
of medical items, prosthetics, spares, and repairs. The earliest application of additive
manufacturing was on the toolroom end of the manufacturing spectrum. For example,
rapid prototyping was one of the earliest additive variants, and its mission was
to reduce the lead time and cost of developing prototypes of new parts and devices,
which was earlier only done with subtractive toolroom methods such as CNC milling,
turning, and precision grinding. In the 2010s, additive manufacturing entered production
to a much greater extent.
In cars, trucks, and aircraft, Additive
Manufacturing is beginning to transform both (1) unibody and fuselage design and
production and (2) powertrain design and production. For example, General Electric
uses high-end 3D printers to build parts for turbines. Many of these systems are
used for rapid prototyping before mass production methods are employed. Other prominent
examples include:
- In early 2014, Swedish supercar manufacturer
Koenigsegg announced the One:1, a supercar that utilizes many components that were
3D printed. Urbee is the first car produced using 3D printing (the bodywork and
car windows were "printed").
- In 2014, Local Motors debuted Strati, a
functioning vehicle that was entirely 3D printed using ABS plastic and carbon fiber,
except the powertrain.
- In May 2015 Airbus announced that its new
Airbus A350 XWB included over 1000 components manufactured by 3D printing.
- In 2015, a Royal Air Force Eurofighter Typhoon
fighter jet flew with printed parts. The United States Air Force has begun to work
with 3D printers, and the Israeli Air Force has also purchased a 3D printer to print
spare parts.
- In 2017, GE Aviation revealed that it had
used design for additive manufacturing to create a helicopter engine with 16 parts
instead of 900, with a great potential impact on reducing the complexity of supply
chains.
Firearm industry
AM's impact on firearms involves two dimensions:
new manufacturing methods for established companies, and new possibilities for the
making of do-it-yourself firearms. In 2012, the US-based group Defense Distributed
disclosed plans to design a working plastic 3D printed firearm "that could
be downloaded and reproduced by anybody with a 3D printer." After Defense Distributed
released its plans, questions were raised regarding the effects that 3D printing
and widespread consumer-level CNC machining may have on gun control effectiveness.
Moreover, armor design strategies can be enhanced by taking inspiration from nature
and prototyping those designs easily possible using additive manufacturing.
Health sector
Surgical uses of 3D printing-centric therapies
have a history beginning in the mid-1990s with anatomical modeling for bony reconstructive
surgery planning. Patient-matched implants were a natural extension of this work,
leading to truly personalized implants that fit one unique individual. Virtual planning
of surgery and guidance using 3D-printed, personalized instruments have been applied
to many areas of surgery including total joint replacement and craniomaxillofacial
reconstruction with great success. One example of this is the bioresorbable tracheal
splint to treat newborns with tracheobronchomalacia developed at the University
of Michigan. The use of additive manufacturing for serialized production of orthopedic
implants (metals) is also increasing due to the ability to efficiently create porous
surface structures that facilitate osseointegration. The hearing aid and dental
industries are expected to be the biggest area of future development using custom
3D printing technology.
3D printing is not just limited to inorganic
materials; there have been a number of biomedical advancements made possible by
3D printing. As of 2012, 3D bio-printing technology has been studied by biotechnology
firms and academia for possible use in tissue engineering applications in which
organs and body parts are built using inkjet printing techniques. In this process,
layers of living cells are deposited onto a gel medium or sugar matrix and slowly
built up to form three-dimensional structures including vascular systems. 3D printing
has been considered as a method of implanting stem cells capable of generating new
tissues and organs in living humans. In 2018, 3D printing technology was used for
the first time to create a matrix for cell immobilization in fermentation. Propionic
acid production by Propionibacterium acidipropionici immobilized on 3D-printed
nylon beads was chosen as a model study. It was shown that those 3D-printed beads
were capable of promoting high-density cell attachment and propionic acid production,
which could be adapted to other fermentation bioprocesses.
3D printing has also been employed by researchers
in the pharmaceutical field. During the last few
Medical equipment
During the COVID-19 pandemic, 3d printers
were used to supplement the strained supply of PPE through volunteers using their
personally owned printers to produce various pieces of personal protective equipment
(i.e. frames for face shields).
Soft actuators
3D printed soft actuators are a growing application
of 3D printing technology that has found its place in the 3D printing applications.
These soft actuators are being developed to deal with soft structures and organs, especially in biomedical sectors and where the interaction between humans and robots
is inevitable. The majority of the existing soft actuators are fabricated by conventional
methods that require manual fabrication of devices, post-processing/assembly, and
lengthy iterations until the maturity of the fabrication is achieved. Instead of the
tedious and time-consuming aspects of the current fabrication processes, researchers
are exploring an appropriate manufacturing approach for the effective fabrication of
soft actuators. Thus, 3D-printed soft actuators are introduced to revolutionize
the design and fabrication of soft actuators with custom geometrical, functional,
and control properties in a faster and inexpensive approach. They also enable the incorporation
of all actuator components into a single structure eliminating the need to use external
joints, adhesives, and fasteners.
Circuit boards
Circuit board manufacturing involves multiple
steps which include imaging, drilling, plating, solder mask coating, nomenclature
printing, and surface finishes. These steps include many chemicals such as harsh
solvents and acids. 3D printing circuit boards remove the need for many of these
steps while still producing complex designs. Polymer ink is used to create the layers
of the build while silver polymer is used for creating the traces and holes used
to allow electricity to flow. Current circuit board manufacturing can be a tedious
process depending on the design. Specified materials are gathered and sent into
inner layer processing where images are printed, developed, and etched. The etch
cores are typically punched to add lamination tooling. The cores are then prepared
for lamination. The stack-up, the buildup of a circuit board, is built and sent
into lamination where the layers are bonded. The boards are then measured and drilled.
Many steps may differ from this stage however for simple designs, the material goes
through a plating process to plate the holes and surface. The outer image is then
printed, developed, and etched. After the image is defined, the material must get
coated with a solder mask for later soldering. Nomenclature is then added so components
can be identified later. Then the surface finish is added. The boards are routed
out of panel form into their singular or array form and then electrically tested.
Aside from the paperwork which must be completed which proves the boards meet specifications,
the boards are then packed and shipped. The benefits of 3D printing would be that
the final outline is defined from the beginning, no imaging, punching, or lamination
is required, and electrical connections are made with the silver polymer which eliminates
drilling and plating. The final paperwork would also be greatly reduced due to the
lack of materials required to build the circuit board. Complex designs which may
take weeks to complete through normal processing can be 3D printed, greatly reducing
manufacturing time.
A 3D selfie in 1:20
scale printed using gypsum-based printing
Hobbyists
In 2005, academic journals had begun to
report on the possible artistic applications of 3D printing technology. Off-the-shelf machines were increasingly capable of producing practical household applications,
for example, ornamental objects. Some practical examples include a working clock
and gears printed for home woodworking machines among other purposes. Web sites
associated with home 3D printing tended to include backscratchers, coat hooks, door
knobs, etc. As of 2017, domestic 3D printing was reaching a consumer audience beyond
hobbyists and enthusiasts. Several projects and companies are making efforts to
develop affordable 3D printers for home desktop use. Much of this work has been
driven by and targeted at DIY/maker/enthusiast/early adopter communities, with additional
ties to the academic and hacker communities.
Sped on by decreases in price and increases
in quality, As of 2019 an estimated 2 million people worldwide have purchased a
3D printer for hobby use.
Legal aspects
Intellectual property
3D printing has existed for decades within
certain manufacturing industries where many legal regimes, including patents, industrial
design rights, copyrights, and trademarks may apply. However, there is not much
jurisprudence to say how these laws will apply if 3D printers become mainstream
and individuals or hobbyist communities begin manufacturing items for personal use,
for non-profit distribution, or for sale.
Any of the mentioned legal regimes may prohibit
the distribution of the designs used in 3D printing or the distribution or sale
of the printed item. To be allowed to do these things, where active intellectual
property was involved, a person would have to contact the owner and ask for a license,
which may come with conditions and a price. However, many patent, design, and copyright
laws contain a standard limitation or exception for "private", or "non-commercial"
use of inventions, designs, or works of art protected under intellectual property
(IP). That standard limitation or exception may leave such private, non-commercial
uses outside the scope of IP rights.
Patents cover inventions including processes,
machines, manufacturing, and compositions of matter and have a finite duration which
varies between countries, but generally 20 years from the date of application. Therefore,
if a type of wheel is patented, printing, using, or selling such a wheel could be
an infringement of the patent.
Copyright covers an expression in a tangible,
fixed medium and often lasts for the life of the author plus 70 years thereafter.
For example, a sculptor retains copyright over a statue, such that other people
cannot then legally distribute designs to print an identical or similar statue without
paying royalties, waiting for the copyright to expire, or working within a fair
use exception.
When a feature has both artistic (copyrightable)
and functional (patentable) merits when the question has appeared in US court,
the courts have often held the feature is not copyrightable unless it can be separated
from the functional aspects of the item. In other countries, the law and the courts
may apply a different approach allowing, for example, the design of a useful device
to be registered (as a whole) as an industrial design on the understanding that,
in case of unauthorized copying, only the non-functional features may be claimed
under design law whereas any technical features could only be claimed if covered
by a valid patent.
Gun legislation
and administration
The US Department of Homeland Security and
the Joint Regional Intelligence Center released a memo stating that "significant
advances in three-dimensional (3D) printing capabilities, availability of free digital
3D printable files for firearms components, and difficulty regulating file sharing
may present public safety risks from unqualified gun seekers who obtain or manufacture
3D printed guns" and that "proposed legislation to ban 3D printing of
weapons may deter, but cannot completely prevent their production. Even if the
practice is prohibited by new legislation, online distribution of these 3D printable
files will be as difficult to control as any other illegally traded music, movie, or software files."
Attempting to restrict the distribution
of gun plans via the Internet has been likened to the futility of preventing the
widespread distribution of DeCSS, which enabled DVD ripping. After the US government
had Defense Distributed take down the plans, they were still widely available via
the Pirate Bay and other file-sharing sites. Downloads of the plans from the UK,
Germany, Spain, and Brazil were heavy. Some US legislators have proposed regulations
on 3D printers to prevent them from being used for printing guns. 3D printing advocates
have suggested that such regulations would be futile, could cripple the 3D printing
industry, and could infringe on free speech rights, with early pioneer of 3D printing
professor Hod Lipson suggesting that gunpowder could be controlled instead.
Internationally, where gun controls are
generally stricter than in the United States, some commentators have said the impact
may be more strongly felt since alternative firearms are not as easily obtainable.
Officials in the United Kingdom have noted that producing a 3D-printed gun would
be illegal under their gun control laws. Europol stated that criminals have access
to other sources of weapons but noted that as technology improves, the risks of
an effect would increase.
Aerospace regulation
In the United States, the FAA has anticipated
a desire to use additive manufacturing techniques and has been considering how best
to regulate this process. The FAA has jurisdiction over such fabrication because
all aircraft parts must be made under FAA production approval or under other FAA
regulatory categories. In December 2016, the FAA approved the production of a 3D-printed fuel nozzle for the GE LEAP engine. Aviation attorney Jason Dickstein has
suggested that additive manufacturing is merely a production method, and should
be regulated like any other production method. He has suggested that the FAA's focus
should be on guidance to explain compliance, rather than on changing the existing
rules and that existing regulations and guidance permit a company "to develop
a robust quality system that adequately reflects regulatory needs for quality assurance".
Impact
Additive manufacturing, starting with today's
infancy period, requires manufacturing firms to be flexible, ever-improving users
of all available technologies to remain competitive. Advocates of additive manufacturing
also predict that this arc of technological development will counter globalization,
as end users will do much of their own manufacturing rather than engage in trade
to buy products from other people and corporations. The real integration of the
newer additive technologies into commercial production, however, is more a matter
of complementing traditional subtractive methods rather than displacing them entirely.
The futurologist Jeremy Rifkin claimed that
3D printing signals the beginning of a third industrial revolution, succeeding the
production line assembly that dominated manufacturing starting in the late 19th
century.
Social change
Since the 1950s, a number of writers and
social commentators have speculated in some depth about the social and cultural
changes that might result from the advent of commercially affordable additive manufacturing
technology. In recent years, 3D printing is creating a significant impact in the humanitarian
and development sector. Its potential to facilitate distributed manufacturing is
resulting in supply chain and logistics benefits, by reducing the need for transportation,
warehousing, and wastage. Furthermore, social and economic development is being advanced
through the creation of local production economies.
Others have suggested that as more and more
3D printers start to enter people's homes, the conventional relationship between
the home and the workplace might get further eroded. Likewise, it has also been
suggested that, as it becomes easier for businesses to transmit designs for new
objects around the globe, so the need for high-speed freight services might also
become less. Finally, given the ease with which certain objects can now be replicated,
it remains to be seen whether changes will be made to current copyright legislation
so as to protect intellectual property rights with the new technology widely available.
As 3D printers became more accessible to
consumers, online social platforms have developed to support the community. This
includes websites that allow users to access information such as how to build a
3D printer, as well as social forums that discuss how to improve 3D print quality
and discuss 3D printing news, as well as social media websites that are dedicated
to sharing 3D models. RepRap is a wiki-based website that was created to hold all
information on 3D printing and has developed into a community that aims to bring
3D printing to everyone. Furthermore, there are other sites such as Pinshape, Thingiverse, and MyMiniFactory, which were created initially to allow users to post 3D files
for anyone to print, allowing for decreased transaction costs of sharing 3D files.
These websites have allowed greater social interaction between users, creating communities
dedicated to 3D printing.
Larry Summers wrote about the "devastating
consequences" of 3D printing and other technologies (robots, artificial intelligence,
etc.) for those who perform routine tasks. In his view, "already there are
more American men on disability insurance than doing production work in manufacturing.
And the trends are all in the wrong direction, particularly for the less skilled,
as the capacity of capital embodying artificial intelligence to replace white-collar
as well as blue-collar work will increase rapidly in the years ahead." Summers
recommends more vigorous cooperative efforts to address the "myriad devices"
(e.g., tax havens, bank secrecy, money laundering, and regulatory arbitrage) enabling
the holders of great wealth to "a paying" income and estate taxes, and
to make it more difficult to accumulate great fortunes without requiring "great
social contributions" in return, including: more vigorous enforcement of anti-monopoly
laws, reductions in "excessive" protection for intellectual property,
greater encouragement of profit-sharing schemes that may benefit workers and give
them a stake in wealth accumulation, strengthening of collective bargaining arrangements,
improvements in corporate governance, strengthening of financial regulation to eliminate
subsidies to financial activity, easing of land-use restrictions that may cause
the real estate of the rich to keep rising in value, better training for young people
and retraining for displaced workers, and increased public and private investment
in infrastructure development -e.g., in energy production and transportation.
Michael Spence wrote that "Now comes
a ... powerful, wave of digital technology that is replacing labor in increasingly
complex tasks. This process of labor substitution and disintermediation has been
underway for some time in service sectors -think of ATMs, online banking, enterprise
resource planning, customer relationship management, mobile payment systems, and
much more. This revolution is spreading to the production of goods, where robots
and 3D printing are displacing labor." In his view, the vast majority of the
cost of digital technologies comes at the start, in the design of hardware (e.g.
3D printers) and, more important, in creating the software that enables machines
to carry out various tasks. "Once this is achieved, the marginal cost of the
hardware is relatively low (and declines as scale rises), and the marginal cost
of replicating the software is essentially zero. With a huge potential global market
to amortize the upfront fixed costs of design and testing, the incentives to invest
[in digital technologies] are compelling."
Naomi Wu regards the usage of 3D printing
in the Chinese classroom (where rote memorization is standard) to teach design principles
and creativity as the most exciting recent development of the technology, and more
generally regards 3D printing as being the next desktop publishing revolution.
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