Modeling, Design and Experimental Characterization of Bending Resonant Circular Nano Cantilevers

This work reports on a new type of nano cantilever, the symmetric circular one, and provides results of its out- of-plane bending natural frequency by means of analytical modeling and experimental testing. The cantilever, with a 225 nm thickness and planar dimensions smaller than 10 � m, can be implemented in dynamic nano electromechanical applica- tions such as atomic force microscopy, surface topology characterization or resonance-shift mass detection. An analytic model is proposed that considers the distributed stiffness and inertia properties through an accurate distribution function. The model also captures the short-beam character of this structure and the related shear effects. Several silicon nitride nano cantilevers have been surface-micromachined and tested by using in-vacuum laser excitation and interferometric measurement of the bending resonant response. The model predictions and the experimental results indicated minimal er- rors. Based on this agreement, the analytical model was utilized to further analyze the influence of the basic geometric pa- rameters on the cantilever's natural frequency.