Applications of the digital holography to the dynamic characterization of MEMS : a micromechanical shunt switch and a micro-gas-sensor

Digital holography is a valid instrument for characterization of micro-electro-mechanical systems (MEMS) with an high resolution and accuracy. In the this paper a brief introduction on the digital holographic microscope will be given, reporting the numerical approach utilized to reduce aberrations, unwrapping phase errors and defocusing of the reconstructed images. Moreover, we present the experimental results on the dynamic characterization of two macrostructured devices. In particular, a dynamic characterization of a micromechanical shunt switch in coplanar waveguide configuration, for microwave application, and a MEMS gas sensor, based on a Pt heater resistor on a Si₃N₄ membrane, has been analyzed.