Question

4. Explain with schematics the two-photon polymerization technique. What is its advantage over stereo lithography?

Answer 1

Stereolithography (SLA or SL; also known as stereolithography apparatus, optical fabrication, photo-solidification, or resin printing) is a form of 3D printing technology used for creating models, prototypes, patterns, and production of parts in a layer by layer fashion using photopolymerization, a process by which light causes chains of molecules to link, forming 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 things such as prototypes for products still in early design, medical models and computer hardware as well as many other applications. While stereolithography is fast and can produce almost any design, it can be expensive.

Advantages-

One of the advantages of stereolithography is its speed; functional parts can be manufactured within a day. The length of time it takes to produce a single part depends upon the complexity of the design and the size. Printing time can last anywhere from hours to more than a day. Many 3D printers can produce parts with a maximum size of approximately 50×50×60 cm.

Disadvantages-

Although stereolithography can be used to produce virtually any synthetic design, it is often costly; common photopolymers can cost about $800 per gallon and SLA machines can cost $250,000. Recently public interest in 3D printing has inspired the design of several consumer SLA machines which can cost $3,500 or less, such as the Ilios Photon 2 by Ilios 3D, Form 2 by Formlabs or the Nobel 1.0 by XYZPrinting. There has also been a reduction of the cost of photopolymer resins.