1. The Drawing Surface:
* The drawing surface is a thin sheet of aluminum powder suspended in a clear plastic film.
* This powder is charged with static electricity by a small metal plate located behind the surface.
2. The Knobs:
* The knobs on the side of the Etch A Sketch are connected to two gears that rotate in opposite directions.
* These gears are linked to two styli, one for each knob.
3. Creating Lines:
* When you turn a knob, the corresponding stylus scrapes across the aluminum powder surface.
* The pressure from the stylus disrupts the static charge on the powder, leaving a trail of ungrounded powder.
* The ungrounded powder appears darker against the background of the charged powder, creating the illusion of a line.
4. Erasing:
* Shaking the Etch A Sketch causes the aluminum powder to settle and redistribute itself.
* The static charge is redistributed, and the ungrounded powder becomes charged again, making the lines disappear.
In essence, you are not actually drawing on the Etch A Sketch; you are altering the distribution of static charge on the aluminum powder to reveal lines. This unique mechanism makes the Etch A Sketch a truly fascinating and enduring toy.