For more, watch [Josh] describe his method in person after the break, or try flashing his code to an Arduino and make a waving cat of your own.

It is also grade school science to show that neither an electromagnet nor a permanent magnet will pick up nonferrous items like copper or aluminum. While technically not an electromagnet ...

Electromagnets have some advantages over permanent magnets. For example: they can be turned on and off the strength of the magnetic field can be varied These properties make electromagnets useful ...