MBE builds molecular scale structures to form objects - just like a MakerBot uses plastic, but on a far smaller scale. If you want an MBE machine at home, take a look at this image:
Oxford Science Park in the UK. Oxford’s scientists can grow a small platter of LEDs in half a day. On a commercial scale, they’ll grow four times each day, generating thousands of LEDs per platter, to produce anything from tens of thousands to millions of finished components with each 24 hour cycle.
This small MBE is actually a baby compared to those found in factories, but serves as an incubator for inventions yet to make it to high street shelves. The idea is that in the future MBE machines may be able to extend beyond LEDs and laser components, to a wider array of everyday electronic gadgets.