As additive manufacturing or 3D printing continues to mature and becomes a viable method, it is important to examine the social implications of decentralized and easily customized manufacturing. Much like an office printer injects ink line by line to make a whole image, 3D printing creates objects by extruding or fusing material layer by layer. Media for manufacturing include thermoplastics and various metals and alloys. 3D printing is an instrumental tool for small-scale customization applications and opens the doors for independent users, but it has raised concerns for its future impact on the economy and its potential to construct weapons.
Additive manufacturing appeared with Hideo Kodoma’s 1981 patent for plastic modeling via built up layers and Chuck Hull’s 1984 patent for a similar method.  More importantly, Hull co-developed the ubiquitous stereolithrography (STL) file format that converts a computer generated model into standard surface geometrical information. STL creates additive layers by depositing small amounts of resin that is quickly dried by a UV light. This process makes strong and nicely finished objects but takes a substantial amount of time to complete.
Since the advent of 3D printing, more methods of building objects layer-by-layer have fallen under the umbrella term “additive manufacturing.” Important milestones include Carl Deckard’s 1997 patent for selective laser sintering (SLS), which fuses powdered media and S. Scott Card’s patent for fused deposition modeling (FDM), which deposits layers of molten thermoplastic much like a hot glue gun does.  The latter method is prevalent among small 3D printers used by hobbyists today due to the simplicity of the machines and relative the low cost of media.
It has been argued that additive manufacturing will transform the economic system, creating a third industrial revolution. The ability for an individual to fabricate objects that would otherwise be manufactured has the potential to change the production and distribution of goods and economy in drastic ways. Many argue that these changes will affect various aspects of the economy, including employment, automation, productivity, and decentralization of production. However, there are conflicting viewpoints about the extent of these transformations.
Rise of Automation
Some commentators predict that increasingly automated production methods will reduce employment opportunities. While factory automation has been a continuing trend, 3D printing offers the possibility of replacing workers who produce more intricate or less-numerous parts and prototypes.  In addition to outright replacement by machines, workers may be forced to compete for lower wages 
Others predict that additive manufacturing will enable workers and firms to stay competitive and technologically advanced. While these advocates do not predict a resurgence of employment opportunities, they cite decreasing production costs as a key benefit of additive manufacturing 
Additive manufacturing has become critical for rapid prototyping and has become useful for building small-scale production runs or custom components. 3D printed prosthetics, art, unique components, and even surgical implants are paraded in social media as a testament to this technology’s potential. Industry is also taking up 3D printing to experiment and to prototype. Surveys show that roughly two-thirds of manufacturers use 3D printing for rapid prototyping or for custom parts.  This is extremely useful for innovating and for experimenting with novel or custom designs that don’t neccesariy need to be mass produced. Small components for unique applications can simply be designed and printed out saving time and resources for producers. Applications are not just limited to manufacturers; orthopedic surgeons are already 3D printing customized joint implants, and even using 3D printed models to understand and visualize complex fractures.  Hobbyist and “do it yourself” enthusiasts are also utilizing additive manufacturing to build components for things they design themselves like art pieces, RC car parts, and drones. While the use of 3D printing has been on the rise within industries and among manufacturers, there has been very limited use among private individuals as most people lack CAD software and skills, let alone a desire to use 3D printing.
In addition to the rapidity and customization offered by 3D printing, the technology allows for intricate designs that could not be produced with traditional methods. Complex internal geometries that cannot be machined may be built up layer by layer using metal sintering. For example, GE’s new LEAP engine features a fuel nozzle with less parts required, higher intricacy resulting in increased efficiency and durability, and less material wastage. 
3D bioprinting, which uses living cells to create structures, is also opening up many new possibilities. By actively constructing structures instead of attempting to grow them from the ground up, this approach holds the possibility of functional tissue grafts and organ replacements. Bioprinting may also be employed to create tissues specifically for research into drugs and toxicology. 
It has been speculated that additive manufacturing will cause a decentralization of manufacturing as the use of 3D printers becomes widespread by individuals. Traditionally, individuals have not possessed the means or desire to create what they need and relied on industry and the free market to supply goods. 3D printing allows anybody to fabricate goods or create a customized component for their own use. The gateway this convenience opens to the average person has raised concerns for the future of manufacturing. Some have speculated that consumers will evolve into “prosumers” or consumers who will simultaneously produce and create products that fit their specific needs or preferences and use fewer products produced by industry. Technologists have argued that people will be able to 3D print their own clothes for a little as a few cents by as early as 2024 which could have negative impacts for the clothing and fashion industry.. Others believe that much of the environmental and ethical costs associated with traditional means of producing meat can be avoided by bio-printing meat. To elaborate, it is estimated that producing 2.2 lbs of beef creates the same amount of pollution produced by a European car that drives 155 miles. Bio-printed meat also appeals to vegetarians that have ethical qualms with eating traditional meat. Much effort has also been made to 3D print biological organs and tissues. 
Alternatively, it is maintained that 3D printing will not see widespread use and will not replace traditional methods of manufacturing. The expectations of 3D printing are easily over hyped and many don’t understand the multitude of constraints with printing including ease of use, strength/quality of product, costs and time involved. Common goods already in mass production cannot possibly be produced as efficiently with 3D printing simply because of the severe time constraint involved with additive manufacturing.
The ease of replicating functional objects or copying artistic features with 3D printing has caused concerns for how patent and copyright laws will protect intellectual property. An instructive parallel is the disruptive effect of electronic transmission and pirating of music during the 1990s. One estimate places the monetary losses due to intellectual property infringement as high as $100 billion annually. 
In a recent case, the U.S. Court of Appeals for the Federal Circuit ruled that the U.S. International Trade Commission had no authority to regulate digital blueprint transmission, even if the information may be used to create an otherwise patented product.  In coming years, courts and regulatory agencies will be called upon to reassess the applicability of patent law to a new technology.
While designs may now be easily distributed and reproduced, quality control due to printer capabilities and operator skill raise new issues with liability law. Some have argued that traditional product liability law cannot be smoothly applied to “micro-sellers” who do not function as traditional firms producing a product do.  Unlike individual sellers, traditional companies may be able to afford extensive product testing and redesigns to meet safety criteria. As 3D printing becomes more widespread, regulators and legislators will be forced to strike a balance between innovation and consumer safety.
Public Safety and Gun Control Advocates
Advocates and enforcers of gun control worry that 3D printed firearms will be impossible to control due to easy dissemination of plans and production technology available to consumers.  The Liberator pistol designed by Defense Distributed an organization that publishes open source firearms-related designs, is made entirely of 3D printed parts and a nail and is capable of firing a single .380ACP cartridge. The Liberator has sparked a widespread discussion about concerns for 3D printed guns.
Government enforcement by the Department of State has attempted to limit distribution of firearms plans by invoking the International Traffic in Arms Regulations (ITAR) legislation which was also used to pursue developers of cryptographic techniques in the 1990s. 
In addition to accessibility, gun control advocates believe that 3D printed guns, currently mostly built from low-cost plastic, will be not be detected by metal detectors. 
Civil Rights Supporters and Defense Distributed
Defense Distributed, the company responsible for the first 3-D printed handgun, has teamed with civil rights supporters to defend their work. These advocates reject regulation on the basis of First (free speech), Second (bearing arms), and Fifth (due process) Amendment-based arguments. 
Some observers note that modern detectors, such as radar-imagers and X-rays, can detect plastic firearms with ease.  These firearms, which have been the subject of public debate, are often dangerous to the user as well. Australian and American enforcement agencies have tested basic, single-shot 3D printed firearms with sometimes-catastrophic results. Depending on the type of plastic used, some test articles exploded during the first shot. 
3D printed plastic weapons are currently limited by durability and longevity concerns due to material limitations. Additionally, 3D printed firearms lack much of the functionality of traditional firearms and commonly available hardware may be used to create functional firearms as well. Solid Concepts, the only company to print a complete firearm using metal, used highly trained engineers and expensive equipment to create a durable firearm equal to those made with traditional methods.
Additive manufacturing holds great promise to both change and introduce production techniques. Decentralization of manufacturing may prove legally and economically disruptive.
Future work should examine the social effects of 3D printing as the technology matures and becomes more widely adopted. Many of the techniques capable of producing usable parts may decline in cost, opening up additional opportunities for users.
Additional research should help legal and regulatory standards adapt to a new technology. Specifically, researchers should strive to understand the economic impacts of intellectual property rights and liability. Public safety must also strike a balance with rights and practicality.
- The Asahi Shimbun. (2014) 
- 3DSystems (2014) 
- U.S. Patent US5597589 
- U.S. Patent US5121329 
- Summer, Lawrence H. (2014) 
- Frey, Carl B. & Osborne, Michael A. (2013) 
- WSJ (2014) 
- Mearian, Lucas (2014) 
- DiPaola, Matthew & Franko, Orrin I. (2013) 
- Allen, Nick (2013) 
- General Electric (2015) 
- Murphy, Sean & Alta, Anthony (2014) Nature Biotechnology(32) 
- Ratto, Matt & Ree, Robert (2012) First Monday17(7) 
- Churney, Max (2014) 
- Wagstaff, Kieth (2012) 
- Murphy, Sean & Alta, Anthony (2014) Nature Biotechnology(32) 
- Allen, Nick (2013) 
- WSJ (2014) 
- Hornick, John. (2015) 
- Gartner, Inc. (2014) 
- Hornick, John & Rosario, Carlos. (2015) 
- U.S. Court of Appeals. (2015) 
- Berkowitz, Nicole. (2014-2015). Washington University Law Review 92(4) 
- Winter, Jana. (2014) 
- Greenberg, Andy. (2015) 
- Israel, Steve. (2013) 
- Greenberg, Andy. (2015) 
- Reynolds, Glenn. (2014) 
- Greenberg, Andy. (2013) 
- Louie, Gilman. (2013) 
- Hadhazy, Adam. (2013) 
- Farago, Robert. (2013)