Introduction to Additive Manufacturing: History, Classification, and Industrial Relevance

If you have ever held a custom phone case printed to match your favorite artwork, worn a set of nearly invisible dental aligners straightening your teeth, or seen a prototype of a new car model tested on a track in a matter of days, you have encountered the output of additive manufacturing (AM) – a family of technologies more commonly known as 3D printing. Unlike traditional manufacturing methods that rely on cutting, milling, or molding to shape materials by removing excess or reforming raw stock, AM builds physical objects directly from digital models by depositing, fusing, or solidizing material layer by layer, a process that closely mirrors the way a traditional inkjet printer builds a two-dimensional image, but extended into the third dimension. This seemingly simple shift in manufacturing logic has triggered a revolution in how products are designed, prototyped, and produced across industries as diverse as aerospace, healthcare, and consumer goods, and it forms the foundation of the technical content covered in this book.

Historical Development of Additive Manufacturing: From Laboratory Prototype to Industrial Mainstream

The origins of additive manufacturing trace back to the early 1980s, when Charles Hull, a California-based engineer working on ultraviolet (UV) light-curable coatings for furniture, conceptualized the first practical 3D printing process. Hull realized that if a focused UV laser could be used to selectively cure liquid photopolymer resin, curing one cross-section of a part at a time, a full three-dimensional object could be built by stacking these cured layers sequentially. In 1984, he filed the first patent for stereolithography (SLA), the foundational technology for all modern vat photopolymerization AM processes, and in 1986 founded 3D Systems Corporation to commercialize the technology. The first commercial SLA printer, the SLA-1, launched in 1988 with a build volume of 10 cm × 10 cm × 10 cm, a maximum resolution of 0

If you have ever held a custom phone case printed to match your favorite artwork, worn a set of nearly invisible dental aligners straightening your teeth, or seen a prototype of a new car model tested on a track in a matter of days, you have encountered the output of additive manufacturing (AM) – a family of technologies more commonly known as 3D printing. Unlike traditional manufacturing methods that rely on cutting, milling, or molding to shape materials by removing excess or reforming raw stock, AM builds physical objects directly from digital models by depositing, fusing, or solidizing material layer by layer, a process that closely mirrors the way a traditional inkjet printer builds a two-dimensional image, but extended into the third dimension. This seemingly simple shift in manufacturing logic has triggered a revolution in how products are designed, prototyped, and produced across industries as diverse as aerospace, healthcare, and consumer goods, and it forms the foundation of the technical content covered in this book.

Historical Development of Additive Manufacturing: From Laboratory Prototype to Industrial Mainstream

The origins of additive manufacturing trace back to the early 1980s, when Charles Hull, a California-based engineer working on ultraviolet (UV) light-curable coatings for furniture, conceptualized the first practical 3D printing process. Hull realized that if a focused UV laser could be used to selectively cure liquid photopolymer resin, curing one cross-section of a part at a time, a full three-dimensional object could be built by stacking these cured layers sequentially. In 1984, he filed the first patent for stereolithography (SLA), the foundational technology for all modern vat photopolymerization AM processes, and in 1986 founded 3D Systems Corporation to commercialize the technology. The first commercial SLA printer, the SLA-1, launched in 1988 with a build volume of 10 cm × 10 cm × 10 cm, a maximum resolution of 0.1 mm layer thickness and ±0.15 mm dimensional accuracy, and was sold for $125,000 per unit when it launched in 1988. The first commercial customer for the SLA-1 was General Motors, which used the system to produce functional prototypes of automotive interior components, reducing its prototype development cycle from 12 weeks to 2 weeks and eliminating the need for expensive hand-carved clay models. This early success demonstrated the commercial value of AM for rapid prototyping, and by 1992, 3D Systems had sold more than 500 SLA systems worldwide, primarily to aerospace, automotive, and consumer electronics companies for product development.

While SLA dominated the industrial AM market in the late 1980s and early 1990s, the development of material extrusion technology, the foundation of modern fused deposition modeling (FDM) printing, began in 1988. Scott Crump, an American inventor and entrepreneur, developed the first FDM process to create a plastic toy frog for his young daughter. Frustrated by the lack of affordable custom toy parts, Crump conceptualized a process that would melt a thermoplastic filament, extrude it through a heated nozzle, and deposit it layer by layer to build a 3D object. He filed a patent for the technology in 1989, and in 1992 co-founded Stratasys, Ltd. to commercialize FDM systems. The first commercial FDM printer, the Stratasys FDM 1650, launched in 1993 with a build volume of 254 mm × 254 mm × 254 mm, a layer thickness of 0.25 mm, and a price tag of $180,000 per unit. Like early SLA systems, the FDM 1650 was targeted exclusively at industrial users for functional prototyping and low-volume part production.

The landscape of AM changed dramatically in 2009, when Dr. Adrian Bowyer, a senior lecturer at the University of Bath in the UK, launched the RepRap (Replicating Rapid-prototyper) open-source project, which released free, open-source designs for a self-replicating FDM printer capable of printing most of its own components. The open-source nature of the RepRap project spurred a global community of hobbyists and entrepreneurs to develop low-cost FDM printers, with the first consumer-grade FDM printers selling for less than $500 by 2012. This democratization of FDM technology expanded the user base of AM from industrial engineers to hobbyists, educators, and small business owners, and laid the foundation for the widespread adoption of 3D printing in the 2010s. For SLA technology, the consumer market took off in 2012 when Formlabs launched the Form 1, the first desktop SLA printer priced at $2,799, a fraction of the cost of industrial SLA systems at the time, making high-resolution resin printing accessible to small businesses, designers, and individual users.

The 2010s also saw the diversification of AM technologies beyond FDM and SLA, with the commercialization of powder bed fusion processes such as selective laser sintering (SLS) for nylon parts and selective laser melting (SLM) for metal parts, as well as material jetting technologies such as PolyJet for multi-material, multi-color printing. By 2020, AM had moved beyond rapid prototyping