The essence of 3D printing is a concept called additive manufacturing that builds up the item one layer at a time.
Regardless of whether it happens in a printer that costs $1,000 or $150,000, the process starts with a digital file that defines the item’s shape and divdes it into tiny slices.
The most prevalent types of 3D printers are:
- Fused deposition. Easily the most popular on campus, these printers force polylactic acid or other polymers through a tiny nozzle that moves back and forth over the model, building up material layer by layer.
- Stereolithography. This specialty printer uses UV lasers to activate a hardening chemical in the raw material as the model is created a slice at a time. A variant of this uses digital light processing elements similar to those used in classroom projectors to form the image.
- Selective laser sintering. Similar to stereolithography, these printers start with a powered raw material that’s built one layer at a time as a laser scans over the item consolidating the material.
- Binder jetting. Invented at MIT and commercialized by HP, this technique builds up the input powder layer by layer as it is sprayed with a hardening chemical.
Brian Nadel is a Pelham, New York-based technology writer.
