History and Technology of Stereolithography
- SLA printing invented by Hideo Kodama in the early 1980s
- French inventors filed a patent for stereolithography process
- Chuck Hull coined the term 'stereolithography' and patented the process
- Chuck Hull co-founded the first 3D printing company, 3D Systems
- Stereolithography achieved industry status in the automotive industry
- Stereolithography is an additive manufacturing process
- UV laser is used to draw a pre-programmed design on the photopolymer vat
- Photopolymer resin is solidified to form each layer of the 3D object
- Build platform lowers one layer at a time, and a blade recoats the top of the tank
- Completed parts need to be washed with a solvent to remove wet resin

Materials Used in Stereolithography
- Resins are commonly used in SLA printing
- Resins can have various properties, such as softness or hardness
- Resins can be filled with secondary materials like glass or ceramic
- Different resins are available for general prototyping, engineering, dental and medical applications, and casting
- Biomaterial resins can be formulated with synthetic or biological polymers

Medical Applications of Stereolithography
- Stereolithographic models used in medicine since the 1990s
- Accurate 3D models created based on data from computer scans
- CT, MRI, or other scans used to acquire data for modeling
- Segmentation process used to isolate specific tissues or organs
- Stereolithographic models used for diagnosis, pre-operative planning, and education in medicine

Advantages and Disadvantages of Stereolithography
Advantages:
- Fast manufacturing process, with functional parts produced within a day
- Printing time depends on complexity and size of design, ranging from hours to more than a day
- SLA printed parts have superior surface quality and no visible layering pattern
- Prototypes and designs made with stereolithography are strong enough to be machined
- Can be used to create master patterns for injection molding and metal casting processes

Disadvantages:
- Often costly, although prices have been decreasing since 2012
- Introduction of consumer SLA machines has made it more affordable
- Photopolymers used in SLA are sticky, messy, and require careful handling
- Newly made parts need to be washed, further cured, and dried
- Limited choice of materials compared to FFF/FDM

Other 3D Printing Methods
- Fused filament fabrication (FFF or FDM)
- Selective laser sintering (SLS)
- Thermoforming
- Laminated object manufacturing (LOM)

Stereolithography (Wikipedia)

Stereolithography (SLA or SL; also known as vat photopolymerisation, optical fabrication, photo-solidification, or resin printing) is a form of 3D printing technology used for creating models, prototypes, patterns, and production parts in a layer by layer fashion using photochemical processes by which light causes chemical monomers and oligomers to cross-link together to form polymers. Those polymers then make up the body of a three-dimensional solid. Research in the area had been conducted during the 1970s, but the term was coined by Chuck Hull in 1984 when he applied for a patent on the process, which was granted in 1986. Stereolithography can be used to create prototypes for products in development, medical models, and computer hardware, as well as in many other applications. While stereolithography is fast and can produce almost any design, it can be expensive.^{[citation needed]}