Measurement and Characterization of Nano-Electro-Mechanical Systems Using Laser Interferometry

In this work, we describe a method to measure and characterize the mechanical properties of nano-electro-mechanical systems (NEMS) based on laser interferometry. The resonant mechanical modes of doubly-clamped nanomechanical beam resonators were first characterized using their thermal fluctuations in air. Afterwards, the NEMS devices were electro-thermally actuated, and their frequency responses were measured, also in air. The main novelty in this work is the simultaneous use of two electro-thermal actuators integrated on opposite ends of the NEMS, which could selectively actuate higher order modes based on the relative phase difference (of 0°, 45° or 90°) applied between the two actuators. All the measurements were carried out in a homodyne Michelson interferometer, allowing for ultrasensitive non-contact, non-invasive, remote, and non-destructive analysis.