Magnetic arrays and their resonant frequencies for the production of binary codes

An array of cantilevers of varying lengths containing at least a layer of magnetic material has been fabricated to produce oscillations at the resonant frequencies of the cantilevers via magneto-mechanical coupling. The acoustic or magnetic fields resulting from the oscillations were detected using microphones or detection coils. The presence or absence of an oscillation at a given frequency of a preselected set of frequencies was used to represent a "1" or a "0", respectively, to create a binary code. The array can be designed and assembled to serve as a multibit magnetic tag.