3D Printer

3D printing or additive manufacturing is the construction of a three-dimensional object from a CAD model or a digital 3D model.^[1][2] It can be done in a variety of processes in which material is deposited, joined or solidified under computer control,^[3] 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.^[4] As of 2019, the precision, repeatability, and material range of 3D printing have 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.^[5]

One of the key advantages of 3D printing^[6] 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 while creating less material waste. 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.^[7]

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History

1940s and 1950s Science Fiction

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 magnetronic 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 photo-cells. But plastic comes out of the end of the drawing arm and hardens as it comes ... following drawings only" ^[11]

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 in 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 are 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 use to 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 for 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.^[12][13]

1980s

Early additive manufacturing equipment and materials were developed in the 1980s.^[14]

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.^[15] He filed a patent for this XYZ plotter, which was published on 10 November 1981. (JP S56-144478).^[16] His research results as journal papers were published in April and November of 1981.^[17][18] 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).^[19] 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.^[20][21]

On 16 July 1984, Alain Le Méhauté, Olivier de Witte, and Jean Claude André filed their patent for the stereolithography process.^[22] The application of the French inventors was abandoned by the French General Electric Company (now Alcatel-Alsthom) and CILAS (The Laser Consortium).^[23] The claimed reason was "for lack of business perspective".^[24]

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.^[25] A team was put together, 6 members^[25] from Exxon Office Systems, Danbury Systems Division, an inkjet printer startup and some members of Howtek, Inc group who became popular figures in the 3D printing industry. ...

On 8 August 1984 a patent, US4575330, assigned to UVP, Inc., later assigned to Chuck Hull of 3D Systems Corporation^[27] 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".^[28][29] 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,^[30] 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.^[26]

Owning a 3D printer in the 1980s cost upwards of $300,000 ($650,000 in 2016 dollars).^[31]

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.

However, 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 microcasting^[32] and sprayed materials.^[33] Sacrificial and support materials had also become more common, enabling new object geometries.^[34]

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).^[26]

In 1995 the Fraunhofer Society developed the selective laser melting process.

2000s

In the early 2000s 3D printers were still largely being used just in the manufacturing and research industries, as the technology was still relatively young and was too expensive for most consumers to be able to get their hands on. The 2000s was when larger scale use of the technology began being seen in industry, most often in the architecture and medical industries, though it was typically used for low accuracy modeling and testing, rather than the production of common manufactured goods or heavy prototyping.^[35]

In the 2005 users began to design and distribute plans for 3D printers that could print around 70% of their own parts, the original plans of which were designed by Adrian Bowyer at the University of Bath in 2004, with the name of the project being RepRap (Replicating Rapid-prototyper).^[36]

Similarly, in 2006 the Fab@Home project was started by Evan Malone and Hod Lipson, another project whose purpose was to design a low-cost and open source fabrication system that users could develop on their own and post feedback on, making the project very collaborative.^[37]

Much of the software for 3D printing available to the public at the time was open source, and as such was quickly distributed and improved upon by many individual users. In 2009 the Fused Deposition Modeling (FDM) printing process patents expired. This opened the door to a new wave of startup companies, many of which were established by major contributors of these open source initiatives, with the goal of many of them being to start developing commercial FDM 3D printers that were more accessible to the general public.^[38]

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^[39] and large nuts^[40] 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 a significant inroad is in the aviation industry. With nearly 3.8 billion air travelers in 2016,^[41] 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....

As technology matured, several authors began to speculate that 3D printing could aid in sustainable development in the developing world.^[45]

In 2012, Filabot developed a system for closing the loop^[46] 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 demonstrated the first multi-material, vertically integrated printed electronics additive manufacturing platform (VIPRE) which enabled 3D printing of functional electronics operating up to 40 GHz.^[47]

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.^[48]

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.^[7] 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,^[citation ^needed] 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.^[49]

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.^[50][51]

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.^[52]

Furthermore, the capabilities of 3D printing have extended beyond traditional manufacturing, with applications in renewable energy systems.^[53] 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.^[54] 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

Main article: 3D modeling

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Materials

Detail of the Stoofbrug [nl] in Amsterdam, the world's first 3D-printed metal bridge^[82]

Traditionally, 3D printing focused on polymers for printing, due to the ease of manufacturing and handling polymeric materials. However, the method has rapidly evolved to not only print various polymers^[83] but also metals^[84][85] and ceramics,^[86] making 3D printing a versatile option for manufacturing. Layer-by-layer fabrication of three-dimensional physical models is a modern concept that "stems from the ever-growing CAD industry, more specifically the solid modeling side of CAD

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Applications

Main article: Applications of 3D printing

The Audi RSQ was made with rapid prototyping industrial KUKA robot

3D printing or additive manufacturing has been used in manufacturing, medical, industry and sociocultural sectors (e.g. cultural heritage) to create successful commercial technology.^[141] 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.^[142]

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.^[143] In the 2010s, additive manufacturing entered production to a much greater extent.

Food

Additive manufacturing of food is being developed by squeezing out food, layer by layer, into three-dimensional objects. A large variety of foods are appropriate candidates, such as chocolate and candy, and flat foods such as crackers, pasta,^[144] and pizza.^[145][146] **NASA is looking into the technology in order to create 3D printed food to limit food waste and to make food that is designed to fit an astronaut's dietary needs.^[147] In 2018, Italian bioengineer Giuseppe Scionti developed a technology allowing the production of fibrous plant-based meat analogues using a custom 3D bioprinter, mimicking meat texture and nutritional values.^[148][149]

Fashion

3D printed necklace.

3D printing has entered the world of clothing, with fashion designers experimenting with 3D-printed bikinis, shoes, and dresses.^[150] In commercial production, Nike used 3D printing to prototype and manufacture the 2012 Vapor Laser Talon football shoe for players of American football, and New Balance has 3D manufactured custom-fit shoes for athletes.^[150][151] 3D printing has come to the point where companies are printing consumer-grade eyewear with on-demand custom fit and styling (although they cannot print the lenses). On-demand customization of glasses is possible with rapid prototyping.^[152]

Transportation

A 3D printed jet engine model.

In cars, trucks, and aircraft, additive manufacturing is beginning to transform both unibody and fuselage design and production, and powertrain design and production. For example, General Electric uses high-end 3D printers to build parts for turbines.^[153] 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.^[154] Urbee is the first car produced using 3D printing (the bodywork and car windows were "printed").^{[155][156][157]}
In 2014, Local Motors debuted Strati, a functioning vehicle that was entirely 3D printed using ABS plastic and carbon fiber, except the powertrain.^[158]
In May 2015 Airbus announced that its new Airbus A350 XWB included over 1000 components manufactured by 3D printing.^[159]
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.^[160]
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 great potential impact on reducing the complexity of supply chains.^[161]

Firearms

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".^[162][163] After Defense Distributed released their plans, questions were raised regarding the effects that 3D printing and widespread consumer-level CNC machining^[164][165] may have on gun control effectiveness.^{[166][167][168][169]} Moreover, armor-design strategies can be enhanced by taking inspiration from nature and prototyping those designs easily, using AM.^[170]

Health

Surgical uses of 3D printing-centric therapies began 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.^[171] 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.^[172][173]

One example of this is the bioresorbable trachial splint to treat newborns with tracheobronchomalacia^[174] 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 areas of future development using custom 3D printing technology.^[175]

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.^[176] 3D printing has been considered as a method of implanting stem cells capable of generating new tissues and organs in living humans.^[177]

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.^[178]

By 3D printing

In 2009, the regeneration of hollow organs and tissues with a long diffusion distance, was a little more challenging. Therefore, to regenerate hollow organs and tissues with a long diffusion distance, the tissue had to be regenerated inside the lab, via the use of a 3D printer.^[2]

Various tissues that have been regenerated by in vitro 3D printing include:

The first organ ever induced and made in the lab was the bladder, which was created in 1999.^[15]

By 2014, there had been various tissues regenerated by the 3D printer and these tissues included: muscle, vagina, penis and the thymus.

In 2014, a conceptual human lung was first bioengineered in the lab.^[16][17] In 2015, the lab robustly tested its technique and regenerated a pig lung.^[16][17] The pig lung was then successfully transplanted into a pig without the use of immunosuppressive drugs.^[16][17]

In 2015, researchers developed a proof of principle biolimb inside a laboratory; they also estimated that it would be at least a decade for any testing of limbs in humans. The limb demonstrated fully functioning skin, muscles, blood vessels and bones.^[18]

In April 2019, researchers 3D printed a human heart.^[19] The prototype heart was made by human stem cells but only to the size of a rabbit's heart.^[19] In 2019, the researchers hoped to one day place a scaled up version of the heart inside humans.^[19]

Gradations of complexity

Level 1	Level 2	Level 3	Level 4
Skin	Blood vessel	Bladder	Heart
Muscle			Liver
Nails			Pancreas
			Penis

With printing tissues, by 2012, there were four accepted standard levels of regenerative complexity that were acknowledged in various academic institutions:

Level one, flat tissue like skin was the simplest to recreate;^[3]
Level two was tubular structures such as blood vessels;^[3]
Level three was hollow non-tubular structures;^[3]
Level four was solid organs, which were by far the most complex to recreate due to the vascularity.^[3]

In 2012, within 60 days it was possible, inside the lab, to grow tissue the size of half a postage stamp to the size of a football field. Most cell types could be grown and expanded outside of the body, with the exception of the liver, nerve and pancreas, as these tissue types need stem cell populations.^[3]

3D printing has also been employed by researchers in the pharmaceutical field. During the last few years, there has been a surge in academic interest regarding drug delivery with the aid of AM techniques. This technology offers a unique way for materials to be utilized in novel formulations.^[179] AM manufacturing allows for the usage of materials and compounds in the development of formulations, in ways that are not possible with conventional/traditional techniques in the pharmaceutical field, e.g. tableting, cast-molding, etc.

Moreover, one of the major advantages of 3D printing, especially in the case of fused deposition modelling (FDM), is the personalization of the dosage form that can be achieved, thus, targeting the patient's specific needs.^[180] In the not-so-distant future, 3D printers are expected to reach hospitals and pharmacies in order to provide on-demand production of personalized formulations according to the patients' needs.^[181]

3D printing has also been used for 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).

Education

3D printing, and open source 3D printers, in particular, are the latest technologies making inroads into the classroom.^{[182][183][184]} Higher education has proven to be a major buyer of desktop and professional 3D printers which industry experts generally view as a positive indicator.^[185] Some authors have claimed that 3D printers offer an unprecedented "revolution" in STEM education.^[186][187]

The evidence for such claims comes from both the low-cost ability for rapid prototyping in the classroom by students, but also the fabrication of low-cost high-quality scientific equipment from open hardware designs forming open-source labs.^[188] Additionally, Libraries around the world have also become locations to house smaller 3D printers for educational and community access.^[189] Future applications for 3D printing might include creating open-source scientific equipment.^[188][190]

3D printed sculpture of an Egyptian pharaoh shown at Threeding

Replicating archeological artifacts

In the 2010s, 3D printing became intensively used in the cultural heritage field for preservation, restoration and dissemination purposes.^[191] Many Europeans and North American Museums have purchased 3D printers and actively recreate missing pieces of their relics^[192] and archaeological monuments such as Tiwanaku in Bolivia.^[193] The Metropolitan Museum of Art and the British Museum have started using their 3D printers to create museum souvenirs that are available in the museum shops.^[194] Other museums, like the National Museum of Military History and Varna Historical Museum, have gone further and sell through the online platform Threeding digital models of their artifacts, created using Artec 3D scanners, in 3D printing friendly file format, which everyone can 3D print at home.^[195]

Replicating historic buildings

The Stoofbrug [nl] in Amsterdam, the world's first 3D-printed metal bridge^[82]

The application of 3D printing for the representation of architectural assets has many challenges. In 2018, the structure of Iran National Bank was traditionally surveyed and modeled in computer graphics software (specifically, Cinema4D) and was optimized for 3D printing. The team tested the technique for the construction of the part and it was successful. After testing the procedure, the modellers reconstructed the structure in Cinema4D and exported the front part of the model to Netfabb.

The entrance of the building was chosen due to the 3D printing limitations and the budget of the project for producing the maquette. 3D printing was only one of the capabilities enabled by the produced 3D model of the bank, but due to the project's limited scope, the team did not continue modelling for the virtual representation or other applications.^[196] In 2021, Parsinejad et al. comprehensively compared the hand surveying method for 3D reconstruction ready for 3D printing with digital recording (adoption of photogrammetry method).^[196]

Soft actuators

3D printed soft actuators is 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 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.^[197] 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.^[198]

Current circuit board manufacturing can be a tedious process depending on the design. .... 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.

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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.^[14] 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.^[234]

The futurologist Jeremy Rifkin^[235] claimed that 3D printing signals the beginning of a third industrial revolution,^[236] 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.^[237] In recent years, 3D printing has created 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.^[142]

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.^[238] 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.^[239] 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.^[240] 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...

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.^[250]

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 importantly, 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."^[251]

...

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.^[252]

Environmental change

The growth of additive manufacturing could have a large impact on the environment. As opposed to traditional manufacturing, for instance, in which pieces are cut from larger blocks of material, additive manufacturing creates products layer-by-layer and prints only relevant parts, wasting much less material and thus wasting less energy in producing the raw materials needed.^[253] By making only the bare structural necessities of products, additive manufacturing also could make a profound contribution to lightweighting, reducing the energy consumption and greenhouse gas emissions of vehicles and other forms of transportation.^[254]

A case study on an airplane component made using additive manufacturing, for example, found that the component's use saves 63% of relevant energy and carbon dioxide emissions over the course of the product's lifetime.^[255] In addition, previous life-cycle assessment of additive manufacturing has estimated that adopting the technology could further lower carbon dioxide emissions since 3D printing creates localized production, and products would not need to be transported long distances to reach their final destination.^[256]

Continuing to adopt additive manufacturing does pose some environmental downsides, however. Despite additive manufacturing reducing waste from the subtractive manufacturing process by up to 90%, the additive manufacturing process creates other forms of waste such as non-recyclable material (metal) powders. Additive manufacturing has not yet reached its theoretical material efficiency potential of 97%, but it may get closer as the technology continues to increase productivity.^[257]

Some large FDM printers that melt high-density polyethylene (HDPE) pellets may also accept sufficiently clean recycled material such as chipped milk bottles. In addition, these printers can use shredded material coming from faulty builds or unsuccessful prototype versions thus reducing overall project wastage and materials handling and storage. The concept has been explored in the RecycleBot.