Additive Device Inc., based in Durham, has raised $650,000 in equity, according to a filing with the US Securities and Exchange Commission.

The filing lists Andrew Miller as promoter, CEO and treasurer, Kurt Jacobus as a director, and Kenneth Gall as an executive officer and director.

Eleven investors participated.

While the company does not have a web site and little other information is available online, the use of “additive manufacturing techniques” to make medical devices is growing rapidly.

While the terms “additive manufacturing” and “rapid prototyping” are often used interchangeably, additive manufacturing specifically refers to production methods that build up a part by adding layers of material. It lowers costs and speeds up development.

Some methods include:

Methods include stereolithography, in which an ultraviolet laser cures or hardens liquid plastic, creating a part layer by layer.

Selective laser sintering heats a powdered material, usually plastic, ceramic or glass, to just under its melting point. It is then hardened and bonded to a 3D structure.

Electron beam melting makes parts by melting powdered metal in a vaccum to eliminate impurities.