Design of a decoupling controller for electrostatically coupled microcantilevers based on current measurement

In this paper we tackle the problem of decoupling the dynamics of closely spaced microcantilevers by using feedback control. In particular, the device we consider consists of two electrostatically actuated cantilevers, that are coupled both mechanically and electrostatically. For this pair, which is described by a time-varying periodic system of equations, we design an optimal /spl Hscr//sub /spl infin// observer, based on the measurement of the current induced on the cantilevers by the voltage applied. The estimate of the cantilevers displacement is then used to generate the control signal that effectively decouples their dynamics. Simulation results are provided that demonstrate the efficacy of the control scheme proposed.