An electroacoustic transducer includes a diaphragm, a tubular first sliding component which surrounds an outer peripheral portion of the diaphragm, a ring-shaped second sliding component which is attached to an outer rim of the diaphragm and slides against an inner peripheral surface of the first sliding component, and a first low-friction membrane interposed between the inner peripheral surface of the first sliding component and an outer peripheral surface of the second sliding component. The first low-friction membrane includes: a swollen body which includes a first polymer chain and a plurality of second polymer chains which branch from the first polymer chain as side chains; and a grease which permeates the second polymer chains.

An electroacoustic transducer includes a diaphragm, a tubular first sliding component which surrounds an outer peripheral portion of the diaphragm, a ring-shaped second sliding component which is attached to an outer rim of the diaphragm and slides against an inner peripheral surface of the first sliding component, and a first low-friction membrane interposed between the inner peripheral surface of the first sliding component and an outer peripheral surface of the second sliding component. The first low-friction membrane includes: a swollen body which includes a first polymer chain and a plurality of second polymer chains which branch from the first polymer chain as side chains; and a grease which permeates the second polymer chains.

A vibrator is provided that includes a substrate having a major surface defined in width and length directions and one or more electrodes formed at least in a substantial entire region of the major surface of the substrate in the length direction, and that performs, as main vibration, expansion-contraction vibration along the width direction in accordance with a voltage applied to the electrodes. Moreover, a holder surrounds at least a portion of the vibrator; and a holding arm connects the vibrator to the holder. Moreover, the vibrator has a width Wo in the width direction positioned at an end in the length direction and includes, to have a width Wm differing from the width Wo and positioned between a pair of ends opposing in the length direction, a variant portion at least one or more locations that is in a shape recessed or projecting in the width direction.

An electromechanical conversion device includes a resonant electrical circuit comprising an inductance and a capacitor, the capacitor including at least a first electrode and a second electrode; and a mechanical oscillator including at least one microbeam formed in a membrane, the first and second electrodes being located side by side and the first electrode of the capacitor being located on a face of the microbeam so that the electrical capacitance of the capacitor varies when the mechanical oscillator oscillates; device wherein the inductance includes an electric track of very low thickness made on the membrane and made of a superconductive material chosen so as to obtain an electric track with a high kinetic inductance.

An electromechanical conversion device includes a resonant electrical circuit comprising an inductance and a capacitor, the capacitor including at least a first electrode and a second electrode; and a mechanical oscillator including at least one microbeam formed in a membrane, the first and second electrodes being located side by side and the first electrode of the capacitor being located on a face of the microbeam so that the electrical capacitance of the capacitor varies when the mechanical oscillator oscillates; device wherein the inductance includes an electric track of very low thickness made on the membrane and made of a superconductive material chosen so as to obtain an electric track with a high kinetic inductance.

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.

A piezoelectric MEMS resonator is provided. The resonator comprises a single crystal silicon microstructure suspended over a buried cavity created in a silicon substrate and a piezoelectric resonance structure located on the microstructure. The resonator is designed and fabricated based on porous silicon related technologies including selective formation and etching of porous silicon in silicon substrate, porous silicon as scarified material for surface micromachining and porous silicon as substrate for single crystal silicon epitaxial growth. All these porous silicon related technologies are compatible with CMOS technologies and can be conducted in a standard CMOS technologies platform.

A piezoelectric MEMS resonator is provided. The resonator comprises a single crystal silicon microstructure suspended over a buried cavity created in a silicon substrate and a piezoelectric resonance structure located on the microstructure. The resonator is designed and fabricated based on porous silicon related technologies including selective formation and etching of porous silicon in silicon substrate, porous silicon as scarified material for surface micromachining and porous silicon as substrate for single crystal silicon epitaxial growth. All these porous silicon related technologies are compatible with CMOS technologies and can be conducted in a standard CMOS technologies platform.

A resonance device that includes a MEMS substrate including a resonator having a vibrating portion, a holding portion configured to hold the vibrating portion, and an isolation groove that surrounds the vibrating portion in a plan view of the resonance device; and an upper lid facing the MEMS substrate with the resonator interposed therebetween and that includes a connection wiring electrically connected to the vibrating portion.

A resonance device that includes a MEMS substrate including a resonator having a vibrating portion, a holding portion configured to hold the vibrating portion, and an isolation groove that surrounds the vibrating portion in a plan view of the resonance device; and an upper lid facing the MEMS substrate with the resonator interposed therebetween and that includes a connection wiring electrically connected to the vibrating portion.