We study the use of vibration localization in large arrays of mechanically coupled, nearly identical microcantilevers for ultrasensitive mass detection and identification. We demonstrate that eigenmode changes in such an array can be two to three orders of magnitude greater than relative changes in resonance frequencies when an analyte mass is added. Moreover, the changes in eigenmodes are unique to the cantilever to which mass is added, thereby providing a characteristic “fingerprint” that identifies the particular cantilever where mass has been added. This opens the door to ultrasensitive detection and identification of multiple analytes with a single coupled array.
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The cantilevers are nominally long, wide, thick, are separated by a distance of , and are made of polysilicon (, ). They are a component of the Cantilever Array Discovery Platform™ chip that is available to CINT Users (see cint. lanl. gov/useṟcall/discovery̱platform. shtml). The lumped parameter mass and stiffness of each individual cantilever, calculated using beam theory, was taken to be and , respectively. The coupling stiffness was chosen to be in order to match theoretical and experimental frequencies.
