Micromechanical/microelectromechanical identification devices and methods of fabrication and encoding thereof

摘要

Encoded devices, for marking various products to which the devices are attached, comprise a comb-like structure comprising a plurality of cantilevered "teeth" or "tines" of different lengths extending from a common support. Each tine has a resonant frequency of vibration dependent upon the length of the tine, and the pattern of tines present on the device comprises the encoded data. Reading of the encoded data is done by setting the tines into vibration and determining the pattern of tines by detecting the presence of the resonant frequency vibrations of the respective tines. Excitation of and read-out of the tines can utilize acoustic, magnetic or electrostatic energy. Fabrication of the devices is preferably done using materials and processes utilized in semiconductor device manufacture. The comb-like structure can be a harp-like structure including beams extending between and secured to opposite sides of the structure, and selected beams are partially severed to provide tines. Alternately, only tines are initially provided and selected times are severed from the structure. Severing of beams or tines is done electrically or mechanically. Also, various materials can be added to the tines for facilitating both the severing and reading out processes.