title: A resonant sensor composed of quartz double ended tuning fork and silicon substrate for digital acceleration measurement.
abstract: Presented in this paper is a micro-resonant acceleration sensor based on the frequency shift of quartz double ended tuning fork (DETF). The structure is silicon substrate having a proof mass supported by two parallel flexure hinges as doubly sustained cantilever, with a resonating DETF located between the hinges. The acceleration normal to the chip plane induces an axial stress in the DETF beam and, in turn, a proportional shift in the beam resonant frequency. Substrate is manufactured by single-crystal silicon for stable mechanical properties and batch-fabrication processes. Electrodes on the four surfaces of DETF beam excite anti-phase vibration model, to balance inner stress and torque and imply a high quality factor. The sensor is simply packaged and operates unsealed in atmosphere for measurements. The tested natural frequency is 36.9 kHz and the sensitivity is 21 Hz/g on a nominally ±100 g device, which is in good agreement with analytical calculation and finite element simulation. The output frequency drifting is less than 0.5 Hz (0.0014% of steady output) within 1 h. The nonlinearity is 0.0019%FS and hysteresis is 0.0026%FS. The testing results confirm the feasibility of combining quartz DETF and silicon substrate to achieve a micro-resonant sensor based on simple processing for digital acceleration measurements.
authors.affiliation: State Key Laboratory for Manufacturing System Engineering, Xi'an Jiaotong University, Xi'an, Shannxi 710049, China.
authors.forename: Cun
authors.initials: C
authors.lastname: Li
authors.affiliation: State Key Laboratory for Manufacturing System Engineering, Xi'an Jiaotong University, Xi'an, Shannxi 710049, China.
authors.forename: Yulong
authors.initials: Y
authors.lastname: Zhao
authors.affiliation: State Key Laboratory for Manufacturing System Engineering, Xi'an Jiaotong University, Xi'an, Shannxi 710049, China.
authors.forename: Rongjun
authors.initials: R
authors.lastname: Cheng
authors.affiliation: State Key Laboratory for Manufacturing System Engineering, Xi'an Jiaotong University, Xi'an, Shannxi 710049, China.
authors.forename: Zhongliang
authors.initials: Z
authors.lastname: Yu
authors.affiliation: State Key Laboratory for Manufacturing System Engineering, Xi'an Jiaotong University, Xi'an, Shannxi 710049, China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Liu