Resonant accelerometer based on double-ended tuning fork and a force amplification mechanism

Resonant accelerometers are an alternative to amplitude modulated devices due to their higher integration capabilities, since they are encapsulated in vacuum and are stable at low pressures. Vacuum is required for some sensors (i.e., gyroscopes) but amplitude modulated accelerometers tend to be unstable under such conditions and therefore cannot be integrated in the same package. Herewith, a device composed by double-ended tuning fork resonators (DETF) and a force amplification mechanism for sensitivity enhancement is presented. Characterization of the fabricated devices was performed, and the design was successfully validated. A sensitivity close to 80 Hz/g was experimentally measured and the DETF characterization for different driving (AC) and bias voltages (DC) is also presented.The first author is supported by FCT– Fundação para a Ciência e Tecnologia through the grant PDE/BDE/114564/2016. This work is supported by FCT with the reference project UID/EEA/04436/2013, COMPETE 2020 with the code POCI-01-0145-FEDER-006941.