There are two types of electrets:
• Real-charge electrets which contain excess free charges such as
• Oriented … See more

Electrets, like magnets, are dipoles. Another similarity is the fields: they produce an electrostatic field (as opposed to a magnetic field) outside the material. When a magnet and an electret are near one another, a r… See more

There is a similarity between an electret and the dielectric layer used in capacitors; the difference is that dielectrics in capacitors have an induced polarisation that is only transient, dependent on the potential ap… See more

Electret materials are quite common in nature. Quartz and other forms of silicon dioxide, for example, are naturally occurring electrets. Today, most electrets are made from synthetic polymers, e.g. fluoropolymers, polypropyle… See more

Bulk electrets can be prepared by heating or melting the material, then cooling it in the presence of a strong electric field. The electric field repositions the charge carriers or aligns the dipoles within the material. When the … See more

• Oliver Heaviside
• Corona wire
• Telephone
• Electret microphone
• Electromotive force… See more

• Jefimenko, Oleg D. (2011). Electrostatic Motors: Their History, Types, and Principles of Operation (1st New Revised ed.). Integrity Research Institute. ISBN 978-1935023470.
• Jefimenko, Oleg D.; Walker, David K. (1… See more