Printing Hollow Structures

 New to me, creates new options for manufacturing.

3D-printing hollow structures with "xolography"

New technique uses criss-crossing light beams in a vat of resin to create simple machines with moving parts

By Charles Q. Choi in Spectrum IEEE

By shining light beams in liquid resin, a new 3-D printing technique dubbed "xolography" can generate complex hollow structures, including simple machines with moving parts, a new study finds.

"I like to imagine that it's like the replicator from Star Trek," says study co-author Martin Regehly, an experimental physicist at the Brandenburg University of Applied Science in Germany. "As you see the light sheet moving, you can see something created from nothing."

onal 3-D printing creates items layer by layer. However, this approach runs into problems when generating hollow objects, since overhanging features will naturally collapse without anything supporting them from underneath.

A number of methods seek to 3-D print hollow structures by shining light at vats of liquid resin. In these so-called volumetric techniques, the light solidifies any liquid it shines on, while the rest of the resin provides support that keeps the hardened material from collapsing.

Now scientists in Germany have invented a new technique called "xolography" capable of significantly greater speeds and higher resolutions than previous volumetric approaches, research detailed in the journal Nature earlier this month. They’ve developed a startup dubbed xolo to commercialize their work.  ....