Abstract Scope |
Electrets in the form of electrical nonconductors (ceramics and polymers) have long been addressed, but this work addresses electrets in the form of conductors (metals such as steel, and carbons such as graphite). The electret behavior of conductors stems from the carrier-atom interaction. In contrast to nonconductive electrets, conductive electrets do not require poling (since the charged state is thermodynamically stable) and allow continuous DC current to pass through. Upon short circuiting, a conductive electret discharges, with its voltage decreasing to zero. Upon subsequent open circuiting, the electret charges back (i.e., self-charge). The discharge/charge is due to capacitor discharge/charge, with the capacitance being the electret-based capacitance (electret charge divided by electret voltage), which is higher than the permittivity-based capacitance by as much as 16 orders of magnitude. This capacitor discharge notion is experimentally supported by the RC time constant for the discharge time and the CVV/2 for the discharge energy. |