This paper presents a new, cheap and accurate experimental method based on electrical harmonic distortion analysis to determine mechanical characteristics (resonant frequency) of MEMS devices used in widespread applications as in energy scavenging, cantilever-based microsystems for gas sensing and atomic force microscopy or in any kind of MEMS resonators. Resonant frequencies ranging from 0.8 kHz to 5 kHz of electrostatic actuated MEMS-based harvesters have been measured by this technique with an uncertainty as low as a few parts in 104 constituting an outstanding result compared to the other methods (optical, capacitive or piezoelectric techniques ). This method uses the mechanical-electrical analogy of MEMS variable capacitor acting as a low-pass filter to give access to both resonant frequency and damping factor of the mechanical system through the determination of the filter parameters by sampling techniques. This method differs from existing ones since it can be applied to MEMS embedded systems where only electrical measurements are allowed, to high Q factor devices where classical methods lack accuracy and even to very damped MEMS that do not display any resonance behavior.
Journal: TechConnect Briefs
Volume: 2, Nanotechnology 2013: Electronics, Devices, Fabrication, MEMS, Fluidics and Computational (Volume 2)
Published: May 12, 2013
Pages: 213 - 215
Industry sector: Sensors, MEMS, Electronics
Topics: MEMS & NEMS Devices, Modeling & Applications