3D printing

The umbrella term additive manufacturing (AM) gained popularity in the 2000s, 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. In industrial and technical settings, additive manufacturing is often the preferred term, and 3D printing is used more by the general public. == 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 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" 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: 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. 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 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 February 1984) to develop Pixelmaster, a color inkjet 2D printer using Thermoplastic (hot-melt) plastic ink, which was commercialized in 1986. A team was put together, 6 members Royden Sanders licensed the Helinksi patent prior to manufacturing the Modelmaker 6 Pro at Sanders prototype, Inc (SPI) in 1993. The first customer of the Modelmaker 6Pro was Hitchner Corporations, Metal Casting Technology, Inc in Milford, New Hampshire, 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 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. 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 and sprayed materials. 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 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). 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. 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. 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 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, reducing parts from 20 to 1, a 25% weight reduction, and reduced assembly times. A fuel nozzle is the perfect inroad 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 technology matured, several authors began 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 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. 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% ) 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. In April 2024, the world's largest 3D printer, the Factory of the Future 1.0 was revealed at the University of Maine. It is able to make objects 96 feet long, or 29 meters. In 2024, researchers used machine learning to improve the construction of synthetic bone and set a record for shock absorption. In July 2024, researchers published a paper in Advanced Materials Technologies describing the development of artificial blood vessels using 3D-printing technology, which are as strong and durable as natural blood vessels. The process involved using a rotating spindle integrated into a 3D printer to create grafts from a water-based gel, which were then coated in biodegradable polyester molecules. == Benefits of 3D printing ==

Additive manufacturing or 3D printing has rapidly gained importance in the field of engineering due to its many benefits. The vision of 3D printing is design freedom, individualization, decentralization and executing processes that were previously impossible through alternative methods. 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, like lightweight construction, or repair and maintenance with applications in prosthetics, bioprinting, food industry, rocket building, design and art and 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. Additive Manufacturing processes generate minimal waste by adding material only where needed, unlike traditional methods that cut away excess material. This reduces both material costs and environmental impact. This reduction in waste also lowers energy consumption for material production and disposal, contributing to a smaller carbon footprint. == General principles ==

Modeling model used for 3D printing 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: • holes • faces normals • self-intersections • noise shells • manifold errors • 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). For that printer resolution, specifying a mesh resolution of and a chord length generates an optimal STL output file for a given model input file. Specifying higher resolution results in larger files without increase in print quality. 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 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. based on acetone or similar solvents. Some additive manufacturing techniques can benefit from annealing as a post-processing step. Annealing a 3D-printed part allows for better internal layer bonding due to recrystallization of the part. It allows for an increase in mechanical properties, some of which are fracture toughness, flexural strength, impact resistance, and heat resistance. Some additively manufactured parts—especially parts that are mission critical—are post-processed with hot isostatic pressing to improve the density and to configure the microstructure to get the required mechanical performance of the printed parts. Additive or 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 decrease 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 ensuring 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 after completing a print. Some commercial metal 3D printers involve cutting the metal component off the metal substrate after deposition. A new process for the GMAW 3D printing allows for substrate surface modifications to remove aluminium or steel. Materials 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 but also metals, chocolates, and ceramics, 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. Before solid modeling was introduced in the late 1980s, three-dimensional models were created with wire frames and surfaces." but in all cases the layers of materials are controlled by the printer and the material properties. The three-dimensional material layer is controlled by the deposition rate as set by the printer operator and stored in a computer file. The earliest printed patented material was a hot melt type ink for printing patterns using a heated metal alloy. Charles Hull filed the first patent on August 8, 1984, to use a UV-cured acrylic resin using a UV-masked light source at UVP Corp to build a simple model. The SLA-1 was the first SL product announced by 3D Systems at Autofact Exposition, Detroit, November 1978. The SLA-1 Beta shipped in Jan 1988 to Baxter Healthcare, Pratt and Whitney, General Motors and AMP. The first production SLA-1 shipped to Precision Castparts in April 1988. The UV resin material changed over quickly to an epoxy-based material resin. In both cases, SLA-1 models needed UV oven curing after being rinsed in a solvent cleaner to remove uncured boundary resin. A post cure apparatus (PCA) was sold with all systems. The early resin printers required a blade to move fresh resin over the model on each layer. The layer thickness was 0.006 inches and the HeCd laser model of the SLA-1 was 12 watts and swept across the surface at 30 inch per second. UVP was acquired by 3D Systems in January 1990. A review of the history shows that a number of materials (resins, plastic powder, plastic filament and hot-melt plastic ink) were used in the 1980s for patents in the rapid prototyping field. Masked lamp UV-cured resin was also introduced by Cubital's Itzchak Pomerantz in the Soldier 5600, Carl Deckard's (DTM) laser sintered thermoplastic powders, and adhesive-laser cut paper (LOM) stacked to form objects by Michael Feygin before 3D Systems made its first announcement. Scott Crump was also working with extruded "melted" plastic filament modeling (FDM) and drop deposition had been patented by William E Masters a week after Hull's patent in 1984, but he had to discover thermoplastic inkjets, introduced by Visual Impact Corporation 3D printer in 1992, using inkjets from Howtek, Inc., before he formed BPM to bring out his own 3D printer product in 1994. 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 that 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, a concept of 3D-printed pills and vaccines has been presented. With this new concept, multiple medications can be combined, which is expected to 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 is 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 has the potential to 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 medical fields. 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 few 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. == Processes ==

was made with rapid prototyping industrial KUKA robots.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. 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. 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. Fashion 3D printing has entered the world of clothing, with fashion designers experimenting with 3D-printed bikinis, shoes, and dresses. • 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 great potential impact on reducing the complexity of supply chains. 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". 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. 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. 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. 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 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. 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. 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. 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. Higher education has proven to be a major buyer of desktop and professional 3D printers which industry experts generally view as a positive indicator. Some authors have claimed that 3D printers offer an unprecedented "revolution" in STEM education. 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. Future applications for 3D printing might include creating open-source scientific equipment. Many Europeans and North American Museums have purchased 3D printers and actively recreate missing pieces of their relics and archaeological monuments such as Tiwanaku in Bolivia. 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. 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. Morehshin Allahyari, an Iranian-born U.S. artist, considers her use of 3D sculpting processes of re-constructing Iranian cultural treasures as feminist activism. Allahyari uses a 3D modeling software to reconstruct a series of cultural artifacts that were demolished by ISIS militants in 2014. Replicating historic buildings and architectural structures 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. 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 that 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. in 1:20 scale printed using gypsum-based printing Hobbyists In 2005, academic journals began to report on the possible artistic applications of 3D printing technology. 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, 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 licence, 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. 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". In 2023, the ISO/ASTM 52920:2023 defined the requirements for industrial additive manufacturing processes and production sites using additive manufacturing to ensure required quality level. Aforetime in Germany there was a draft of DIN norm issued, DIN SPEC 17071:2019. == Health and safety ==

Polymer feedstock materials can release ultrafine particles and volatile organic compounds (VOCs) if sufficiently heated, which in combination have been associated with adverse respiratory and cardiovascular health effects. In addition, temperatures of 190 °C to 260 °C are typically reached by an FFF extrusion nozzle, which can cause skin burns. Vat photopolymerization stereolithography printers use high-powered lasers that present a skin and eye hazard, although they are considered nonhazardous during printing because the laser is enclosed within the printing chamber. Research on the health and safety concerns of 3D printing is new and in development due to the recent proliferation of 3D printing devices. In 2017, the European Agency for Safety and Health at Work published a discussion paper on the processes and materials involved in 3D printing, the potential implications of this technology for occupational safety and health and avenues for controlling potential hazards. Noise level is measured in decibels (dB), and can vary greatly in home printers from 15 dB to 75 dB. Some main sources of noise in filament printers are fans, motors and bearings, while in resin printers the fans usually are responsible for most of the noise. Some methods for dampening the noise from a printer may be to install vibration isolation, use larger diameter fans, perform regular maintenance and lubrication, or use a soundproofing enclosure. == 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. 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 , Namibia, advertising 3D printing, July 2018 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. A printer was donated to the Juan Fernandez Women's Group in 2024, to support women in the remote community to be able to create parts to fix broken equipment, without having to wait for a ship to import the needed components. Environmental change The growth of additive manufacturing could have a large impact on the environment. Traditional subtractive manufacturing methods such as CNC milling create products by cutting away material from a larger block. In contrast, additive manufacturing creates products layer-by layer, using the minimum required materials to create the product. This has the benefit of reducing material waste, which further contributes to energy savings by avoiding raw material production. Life-cycle assessment of additive manufacturing has estimated that adopting the technology could further lower carbon dioxide emissions since 3D printing creates localized production, thus reducing the need to transport products and the emissions associated. AM could also allow consumers to create their own replacement parts to fix purchased products to extend the lifespan of purchased products. By making only the bare structural necessities of products, additive manufacturing also has the potential to make profound contributions to lightweighting. A case study on an airplane component made using additive manufacturing, for example, found that the use of the component saves 63% of relevant energy and carbon dioxide emissions over the course of the product's lifetime. However, the adoption of additive manufacturing also has environmental disadvantages. Firstly, AM has a high energy consumption compared to traditional processes. This is due to its use of processes such as lasers and high temperatures for product creation. Secondly, despite additive manufacturing reducing up to 90% of waste compared to subtractive manufacturing, AM can generate waste that is non-recyclable. For example, there are issues with the recyclability of materials in metal AM as some highly regulated industries such as aerospace often insist on using virgin powder in the creation of safety critical components. Despite the drawbacks, research and industry are making further strides to support AM's sustainability. 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 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. There are also industrial efforts to produce metal powder from recycled metals. == See also ==