The Lix 3D printing pen is not the first pen that lets you create 3D plastic doodles -- the 3Doodler pen does that quite well -- but the Lix pen is lighter and easier to grip.
This 3D pen uses straight plastic rods that are fed into it from the top. The plastic goes through a heated nozzle at the pen's tip and is heated to temperatures up to 190 degrees Centigrade, and emerges as a flexible, soft material that you can draw with. Once the plastic leaves the pen, it hardens and maintains its shape, allowing you to create sturdy 3D structures. Each plastic rod is good for about two minutes of drawing. With some practice, you can create intricate artwork, jewelry and sculptures.
The Lix 3D printing pen will be available for around $140. A ballpoint version is also in the works and will cost about $60.