Synchronous detection of multiple micro-substances with a single output channel using a weakly coupled resonator array

Abstract In this paper, a multiple micro-substances sensing scheme with a single output channel using a weakly coupled resonator array is proposed. An analytical model of the resonator using the Euler–Bernoulli beam theory has been developed, as well as the dynamic behavior has been further explored using the Galerkin method. We have discovered numerically that, in the weakly coupled cantilever array, the A-f (amplitude-frequency) curve of any cantilever physically reflects the vibration features of other cantilevers. Hence, by measuring the output signal of a single cantilever, multiple substances applied on each cantilever respectively can be identified and detected synchronously. A single output channel via a weakly coupled micro-resonator array is constructed and validated numerically for picogram level mass detection. Equivalent experiments with a macro coupled five-cantilever array have been further conducted for verification. Under a common sweep-driven signal, the five analytes applied on each cantilever with masses at microgram level can be detected synchronously and independently by measuring the frequency shifts of the five resonant peaks of the center cantilever. Multiple substances sensing with a single output channel and a single driving signal is thus realized with low relative errors and high linearities. By enhancing the driving voltage, the mass resolution can also be improved via Duffing bifurcation. This work not only reveals a new coupled vibration behavior but also provides a new avenue for multiple analytes detection.