Which AM method builds part layers by exposing build material to radiation emitted by light?

The correct answer is vat photopolymerization. This additive manufacturing method specifically uses light radiation, typically from UV light sources, to cure and solidify liquid resin layer by layer to create a three-dimensional object. In vat photopolymerization, a vat filled with photosensitive resin is utilized, and as the light selectively exposes certain areas of the resin, it hardens those sections into solid layers. The process continues as the build platform lowers into the resin, allowing for further layers to be built on top of the already cured material.

In contrast, binder jetting employs a liquid binding agent to selectively bond powder particles together, without using light radiation. Fused filament fabrication involves extruding thermoplastic filament through a heated nozzle, which doesn’t involve curing a liquid material with radiation. Selective laser sintering utilizes a laser to sinter powdered material together, but again, it does not rely on light exposure in the same way that vat photopolymerization does. Each of these methods utilizes different materials and mechanisms, emphasizing the unique characteristics of vat photopolymerization as the process that specifically involves the use of light radiation to solidify liquid resin.