Home Chapter 3 Insulators and dielectrics
Insulators and dielectrics
Book - Chapter 3

Well, we have fully discussed and measured voltages and now we need to consider insulators. Insulators do not readily conduct electricity.

Some common examples of these are plastic, wax, and air. They do not conduct because they do not have valence electrons to support current flow. However, if given enough electrical pressure, like a high voltage, the insulator will conduct and will pass current. This is called the breakdown voltage, which is when the material can not longer hold back the pressure of voltage.

Insulators are also called dielectrics because they resist the passage of current. Dielectrics literally hold back the pressure of current, as they do not have any charge carriers (electrons) to contribute to current movement though compounds.


A Dielectric is a non-conductor.


Air is a perfect example of an insulator conducting as it allows the high pressure of lightning to pass through the air with the assistance of the moisture of water as we are aware  the Walter De Maria work the Lightening Field would permit.

Kapton and Mylar are examples of materials that have dielectric strengths of 7000 volts per mil (a mil is .001 of an inch), but even things like air and glass have dielectric strengths of a lot less--in the 80 to 200 per mil range. Almost any material will conduct if given enough voltage pressure.

Lighting is a great example of this.

While metal is a good conductor and plastic is not a good conductor, we now have a new class of conductive polymers made of plastic. Yes, PLASTIC! From research done at the end of 1979, the researchers Heeger, MacDiarmid, and Shirakawa2 were awarded Nobel Laureates in Chemistry for their discovery that plastics could be manipulated to make them electrically conductive. They discovered that they could “dope” plastics with iodine vapor which enhances the conductivity of polyacetylene, so that electrons could move along the plastic, while conducting. One product that has come out of this is electroluminescent film.


Dope is where you add some material to another to alter the optical/electrical properties of a semiconductor.


The main lesson here is that charge carriers affect the ability of material to conduct electron flow.