Which rapid prototyping process fabricates a part layer-wise by hardening a resin with a guided laser beam?

• A. SLS
• B. Stereolithography (SLA)
• C. Direct metal laser sintering (DMLS)
• D. Fusion deposition modelling (FDM)

Answer: (B)

This question is about how rapid prototyping builds parts layer by layer by transforming a liquid resin with a directed light source. The described method uses a resin that is hardened when the laser beam touches it, layer after layer, to form the 3D geometry. That precisely matches stereolithography, which uses a UV (or visible) laser to selectively cure a vat of photosensitive resin according to each cross-section from the CAD model. The other processes operate differently: they either fuse or sinter powders (not a liquid resin) or extrude melted plastic, rather than curing a resin with a laser. So the best match is stereolithography.