Field Emission displacement gauge for microelectomechanical resonators

In this paper we present the design, fabrication and test of a MEMS resonator including a field emission gauge for the measurement of the resonator movements. The device is made of an in plane vibrating structure containing electrostatic actuation electrodes as well as a dual tip field emission structure. One tip is fixed where the other, standing about one micron in front of it, is attached to the vibrating structure. When biased with a high voltage in vacuum, a field emission current appears between the tips, this current is modulated by the variation of the tip-to-tip distance, thus allowing monitoring the vibration of the structure. This paper will show microfabrication process, finite element modeling and measurement results of the system.