A microelectromechanical device having a mobile structure including mobile arms formed from a composite material and having a fixed structure including fixed arms capacitively coupled to the mobile arms. The composite material includes core regions of insulating material and a silicon coating.

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.

There is disclosed acoustic resonators and filter devices. An acoustic resonator includes a substrate having a surface and a single-crystal piezoelectric plate having front and back surfaces, the back surface attached to the surface of the substrate except for a portion of the piezoelectric plate forming a diaphragm that spans a cavity in the substrate. An interdigital transducer (IDT) is formed on the front surface of the single-crystal piezoelectric plate such that interleaved fingers of the IDT are disposed on the diaphragm. The interleaved fingers of the IDT are substantially molybdenum. The piezoelectric plate and the IDT are configured such that a radio frequency signal applied to the IDT excites a primary shear acoustic mode in the diaphragm. A thickness of the interleaved fingers of the IDT is between 0.25 times and 2.5 times a thickness of the piezoelectric plate.

A resonance device is provided having a resonator with opposing upper and lower lids. The resonator includes a base, and multiple vibration arms that are connected to a front end of the base so as to extend away from the base. Moreover, a frame surrounds a periphery of the base portion and the vibration arms and one or more holding arms connect the base to the frame. The base, the vibration arms, and the holding arm include a substrate and a temperature characteristics correction layer laminated on the substrate and having a material with a coefficient of thermal expansion different from that of the substrate. The base, the vibration arms, and the holding arm are formed integrally with the substrate and the temperature characteristics correction layer.

A resonator is provided that includes a base, and three or more vibrating arms each including a first and second electrodes and a piezoelectric film disposed therebetween and having a top surface facing the first electrode. The piezoelectric film vibrates in a predetermined vibration mode when a voltage is applied between the first and second electrodes. Moreover, the three or more vibrating arms include two first arms each located on an outermost side in a direction in which the three or more vibrating arms are arranged and that vibrate in a same phase, and one or more second arms disposed between the two first arms. Each first arm is greater in mass than each second arm.

The accelerometers disclosed herein provide excellent sensitivity, long-term stability, and low SWaP-C through a combination of photonic integrated circuit technology with standard micro-electromechanical systems (MEMS) technology. Examples of these accelerometers use optical transduction to improve the scale factor of traditional MEMS resonant accelerometers by accurately measuring the resonant frequencies of very small (e.g., about 1 m) tethers attached to a large (e.g., about 1 mm) proof mass. Some examples use ring resonators to measure the tether frequencies and some other examples use linear resonators to measure the tether frequencies. Potential commercial applications span a wide range from seismic measurement systems to automotive stability controls to inertial guidance to any other application where chip-scale accelerometers are currently deployed.

A resonator element of the monocrystalline 4H or 6H polytype of silicon carbide. A MEMS device including the resonator element and a substrate, wherein the resonator element and the substrate are not coplanar, and acoustic decoupling of the resonator element and the substrate is at least partially dependent upon a degree to which the resonator element and the substrate are not coplanar. A MEMS gyroscope including the resonator element, a substrate, one or more electrodes disposed proximate the resonator element, and a capacitive gap disposed between each electrode and the resonator element. A MEMS device including the resonator element having has a Q greater than 1,000,000, a phononic crystal substrate, and a gap disposed between a perimeter edge of the resonator element and the phononic crystal substrate, wherein acoustic decoupling of the resonator element and the phononic crystal substrate is at least partially dependent upon a size of the gap.

According to one embodiment, a resonator is disclosed. The resonator includes a vibrator and an attenuation mechanism. The attenuation mechanism selectively attenuates vibration of a spurious mode that is mechanically coupled to a first mode when the vibrator vibrates in the first mode.

Micro-Electro-Mechanical System (MEMS) devices for harvesting sound energy and methods for fabricating MEMS devices for harvesting sound energy are provided. In an embodiment, a method for fabricating a MEMS device for harvesting sound energy includes forming a pressure sensitive MEMS structure disposed over a semiconductor substrate and including a suspended structure in a cavity. Further, the method includes etching the semiconductor substrate to form an acoustic port through the semiconductor substrate configured to allow acoustic pressure to deflect the suspended structure.

A micro-electrical-mechanical system (MEMS) guided wave device includes a plurality of electrodes arranged below a piezoelectric layer (e.g., either embedded in a slow wave propagation layer or supported by a suspended portion of the piezoelectric layer) and configured for transduction of a lateral acoustic wave in the piezoelectric layer. The piezoelectric layer permits one or more additions or modifications to be made thereto, such as trimming (thinning) of selective areas, addition of loading materials, sandwiching of piezoelectric layer regions between electrodes to yield capacitive elements or non-linear elastic convolvers, addition of sensing materials, and addition of functional layers providing mixed domain signal processing utility.