Enhanced Second-Order Resonance Actuation and Frequency Response Modulation of Microcantilever by Dual Coplanar Counter Electrodes

We achieve enhanced actuation of the 2^nd-order resonance of a microcantilever in a capacitive microcantilever structure featured by a dual coplanar counter electrodes configuration. A torque about the static point of the 2^nd eigenmode is generated in this configuration and therefore enables effective actuation of the 2^nd-order resonance. It is further confirmed that the torque has the effect of suppressing the 1^st-order resonance. As a result, the frequency response curve of the microcantilever beam can be modulated. Our results suggest that electric actuation of any higher-order resonances of the microcantilever can be realized through a rational design of counter electrodes.