Desing of a voltage Shaker

We want to understand better the main laws of electromagnetism and experience the potential of the electric and magnetic fields in order to generate electric current; -These concepts are very abstract and for some people they are difficult to understand, because it is something you cannot see or touch, so we try to make a device that shows the immediate effects of these fields -Compare the theoretical results with the practical by the basic laws of electromagnetism. -Manufacture a functional tool, handy and easy to use, which can be used by everyone, including children and elderly. Therefore, it must be lightweight weighing, less than 500 grams, and small size. It must also generate enough electric current to be used for different purposes. Around 3 or 5 volt.