An Investigation into the Mechanical Behavior of Multi- Input and Multi-Output MEMS Resonators

We investigate theoretically and experimentally the mechanical behavior of Micro electromechanical systems MEMS resonators with multiple input (actuation) and output (detection) methods. The devices are based on a compound resonator consisting of an in-plane clamped-guided arch beam that is mechanically coupled from its guided side to another T-shaped resonant beam. Tensile and compressive bi-directional electrostatic axial forces are induced on the T-shaped resonator, which modulate the stiffness of both the arch and the T-shaped beams resonators, thereby changing their resonance frequencies to lower or higher values. At the coupling point of the two resonators, additional two flexure beams are attached, which provide another electrothermal tuning capability. The electrothermal actuators can be configured in various ways to adjust, as desired, the mechanical stiffness of the resonators; thereby controlling their resonance frequency. Therefore, this structure offers various electrothermal and electrostatic actuation and read-out possibilities, which can lead to complex device functionalities based on multiple inputs and outputs. As an example, we experimentally demonstrate an electromechanical resonant 1:2 DEMUX logic element. The logic operation is based on the linear frequency modulation. This study demonstrates that with such compound MEMS resonators, it is possible to build more complex logic functionalities.