This Magic Pen Can Draw Working Electronic Circuits On Paper With Conducting Ink
AgiC is a Japanese startup that has designed an amazing pen that conducts electricity even as the lines are drawn by the artist. The AgiC electricity conductive pen is available on amazon. You can get it here
The conductive pen ugiC uses silver ink which connects the circuits via drawn lines.
Watch the electric conductive pen in action as a small 3D paper town is brought to life: