A resonator includes a support frame, a rectangular vibrating plate that performs contour vibration in a predetermined direction, and two pairs of support arms. The vibrating plate includes four vibration regions arranged in a row in the lengthwise direction and electrodes disposed in the vibration regions. Each of the vibration regions vibrate with a phase opposite to phases with which the adjacent vibration regions vibrate upon excitation. A center line of a pair of the electrodes in the lengthwise direction is offset from a center line, in the lengthwise direction, of a corresponding vibration region that includes the electrode disposed thereon.

The present disclosure provides an aerosol sensing method. The aerosol sensing method includes steps of providing an entering process, providing a particle collecting process and providing a measuring process. The entering process is to allow an aerosol to enter a chamber of a thermal-piezoresistive oscillator-based aerosol sensor, and a thermal-piezoresistive resonator is disposed in the chamber. The particle collecting process is to allow particulate matters in the aerosol to land on at least one proof-mass of the thermal-piezoresistive resonator when the thermal-piezoresistive resonator is not driven. The measuring process is to use an electrical signal to drive the thermal-piezoresistive resonator and measure a resonant frequency of the thermal-piezoresistive resonator. The particle collecting process and the measuring process are operated in a repetitive cycle for measuring changes of the resonant frequency of the thermal-piezoresistive resonator to measure the particulate matters of the aerosol.

A resonator is provided that includes a vibration portion having a first and second electrodes, a piezoelectric film disposed therebetween and having a first face opposing the first electrode, and at least two temperature characteristic adjustment films formed to oppose the first face of the piezoelectric film with the first electrode interposed therebetween. Moreover, the resonator includes a frame that surrounds at least part of the vibration portion; and a holding arm connecting the vibration portion to the holding portion. The vibration portion includes a surface opposing the first face of the piezoelectric film and having first and second regions in which an average amount of displacement is larger than an average amount of displacement in the first region when the vibration portion vibrates.

Multiple degenerately-doped silicon layers are implemented within resonant structures to control multiple orders of temperature coefficients of frequency.

A microelectromechanical system (MEMS) resonator includes a degenerately-doped single-crystal silicon layer and a piezoelectric material layer disposed on the degenerately-doped single-crystal silicon layer. An electrically-conductive material layer is disposed on the piezoelectric material layer opposite the degenerately-doped single-crystal silicon layer, and patterned to form first and second electrodes.

A micromechanical vibrasolator isolates vibration of a micromechanical resonator and includes: phononic bandgap mirrors, monophones connected serially; phonophore arms in an alternating sequence of phonophore arm-monophone-phonophore arm; abutments in acoustic communication with the phononic bandgap mirrors; wherein the micromechanical resonator is interposed between the phononic bandgap mirrors with phononic bandgap mirror arranged in parallel on opposing sides of the micromechanical resonator arranged perpendicular to a direction of vibration of an in-plane vibrational mode of the micromechanical resonator.

Multiple degenerately-doped silicon layers are implemented within resonant structures to control multiple orders of temperature coefficients of frequency.

A micromechanical resonator is provided that enables a smaller total package size with an acceptable quality factor for timing applications. The MEMS resonator includes a vibration portion with a base and three or more vibrating beams extending therefrom. Moreover, the MEMS resonator includes a frame that surrounds a periphery of the vibration portion and a pair of anchor between the vibrating beams for stabilizing the vibration portion within the frame. Furthermore, support beams couple the base of the vibration portion to the pair of anchors.

MEMS based sensors, particularly capacitive sensors, potentially can address critical considerations for users including accuracy, repeatability, long-term stability, ease of calibration, resistance to chemical and physical contaminants, size, packaging, and cost effectiveness. Accordingly, it would be beneficial to exploit MEMS processes that allow for manufacturability and integration of resonator elements into cavities within the MEMS sensor that are at low pressure allowing high quality factor resonators and absolute pressure sensors to be implemented. Embodiments of the invention provide capacitive sensors and MEMS elements that can be implemented directly above silicon CMOS electronics.

The present disclosure provides an aerosol sensing method. The aerosol sensing method includes steps of providing an entering process, providing a particle collecting process and providing a measuring process. The entering process is to allow an aerosol to enter a chamber of a thermal-piezoresistive oscillator-based aerosol sensor, and a thermal-piezoresistive resonator is disposed in the chamber. The particle collecting process is to allow particulate matters in the aerosol to land on at least one proof-mass of the thermal-piezoresistive resonator when the thermal-piezoresistive resonator is not driven. The measuring process is to use an electrical signal to drive the thermal-piezoresistive resonator and measure a resonant frequency of the thermal-piezoresistive resonator. The particle collecting process and the measuring process are operated in a repetitive cycle for measuring changes of the resonant frequency of the thermal-piezoresistive resonator to measure the particulate matters of the aerosol.