We've heard of 3D-printing pens before, but this LIX Pen really takes the tech up a notch. The aluminum 3D-printing pen really is pen-sized; measuring in at 6.45 inches long, 0.55 inch in diameter and weighs in at just 1.23 ounces.  Once you plug in the jack to your computer, the the plant-based PLA filament inside gets heated up which is then fed in through a hole in the base and emerges as a super-heated liquid on the tip. All that's left from there is for you to start doodling in the air.