Clearly this 3D printing pen is innovative, but that does not necessarily imply that it includes patentable inventions. The technology used looks like FDM (fused deposition modeling) 3D printing extended to free hand, without support material.
The key technology here that makes this 3D/air printing possible is the gooey material that the pen releases. If this material has properties that other existing materials do not have, then it may be patentable. Also if the pen releases material in a manner that is new and novel, then it too may be patentable.
I more or less did this 2 weeks ago while testing the extruder for my 3d printer (and I'm no pioneer here). I used Kliment's (parent of thread) software to cause filament to extrude from my 3d printer's nozzle (the hot end) while I tried to write letters to test it was working ok.
Now someone is trying to claim this "new technology" is patentable.
The key technology here that makes this 3D/air printing possible is the gooey material that the pen releases. If this material has properties that other existing materials do not have, then it may be patentable. Also if the pen releases material in a manner that is new and novel, then it too may be patentable.