Flame-sprayed ceramic dielectric for transducers

A high speed electro-mechanical transducer system based on the Johnsen-Rahbek effect is described, in which a flame-sprayed ceramic of high permittivity replaces the conventional semi-conduétor. Among advantages of the system are its operation at high pulse repetition freqiencies, relatively large mechanical thrusts obtainable at low signal voltages, good wear characteristics, as well as ease and economy of producing large ceramic rotors.