Virtually silent, runs off 4 x AA batteries.
And the best bit?
It's only $99 for the printer (build volume: 76 mm x 128 mm x 52 mm; vertical build rate of about 10 mm/hour or so), and $15 for a 100 mL bottle of resin (a range of hard and flexible resins available); prints with virtually no waste.
http://www.olo3d.net/
https://www.kickstarter.com/projects/olo3d/olo-the-first-ever-smartphone-3d-printer
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I want one!
It sounds too good to be true - I'll believe this is a real thing when I see one actually working.
(But to quote “The X-Files”: I want to believe!)