Hand battery
Are you charged? Place one hand on the aluminium plate and the other hand on the copper plate and see what happens.
When you place your hands on the plates an exchange of electrons between the plates starts. This is an electrical current that can be registered on the current meter. A lie detector (polygraph) works on a similar principle, but in this case what is measured is stress, as expressed in, for example, hand sweat. Damp, sweaty hands are better conductors of electricity.