A resonant member of a MEMS resonator oscillates in a mechanical resonance mode that produces non-uniform regional stresses such that a first level of mechanical stress in a first region of the resonant member is higher than a second level of mechanical stress in a second region of the resonant member. A plurality of openings within a surface of the resonant member are disposed more densely within the first region than the second region and at least partly filled with a compensating material that reduces temperature dependence of the resonant frequency corresponding to the mechanical resonance mode.

Semiconductor strain gages fabricated on Silicon-on-insulator (SOI) material, and the method of making them. Force sensing elements are uniformly batch-fabricated at wafer level and singulated individually by a wire bonding method. In another method, they are singulated by plucking them off the wafer from their attachment site.

A process for producing a piezoelectric sensor includes the following steps: a step of providing a housing made of stainless steel; a step of producing a solution of a compound comprising a metal or metalloid element; a step of depositing a layer of the solution over at least one inner surface of the housing; a step of oxidizing the deposited layer of solution; a step of placing a piezoelectric element inside the housing; a step of closing the housing. A piezoelectric sensor obtained by means of such a process and comprising a closed steel housing, a piezoelectric element arranged inside the housing and a layer of a solution of a compound comprising a metal or metalloid element that is arranged over at least one inner surface of the housing.

A method for manufacturing a PMUT device including a piezoelectric element located at a membrane element is provided. The method includes receiving a silicon on insulator substrate having a first silicon layer, an oxide layer, and a second silicon layer. Portions of a first surface of the second silicon layer are exposed by removing exposed side portions of the first silicon layer and corresponding portions of the oxide layer, and a central portion including the remaining portions of the first silicon layer and of the oxide layer is defined. Anchor portions for the membrane element are formed at the exposed portions of the first surface of the second silicon layer. The piezoelectric element is formed above the central portion, and the membrane element is defined by selectively removing the second layer and removing the remaining portion of the oxide from under the remaining portion of the first silicon layer.

A method for providing a piezoelectric device is described. The method includes providing a first electrode layer on a substrate and coating at least one layer of piezoelectric material. The coating using at least one of clot-die coating, dip coating, aerosol coating and R2R coating such that a layer of the at least one layer of piezoelectric material has a variation in thickness of not more than ten percent. The layer(s) of piezoelectric materials are also heat treated. Multiple layers of piezoelectric material may be slot-die coated and heat treated to provide a multilayer having the desired thickness. A second electrode layer is provided on the layer(s) of piezoelectric material.

A MEMS device includes a membrane portion, a piezoelectric layer made of a piezoelectric single crystal, a first electrode on a first surface of the piezoelectric layer, a second electrode on a second surface of the piezoelectric layer opposite to the first direction, and a first layer covering the first surface of the piezoelectric layer. At least a portion of the piezoelectric layer is included in the membrane portion. Each of the first electrode and the second electrode has a tapered cross-sectional shape with a width which decreases with increasing distance from the piezoelectric layer on a cross section along a plane vertical to the surface in the first direction.

A mechanical microsystem including a pair of elastically deformable elements, a mechanical hinge joining the deformable elements together, and at least two electroactive layers. The microsystem is configured such that, from a rest position wherein the deformable elements fall into a plane, a deformation of one of the deformable elements displacing it outside of the plane induces an electric current circulation in one of the two electroactive layers, and/or conversely. Each deformable element has a front face and a rear face opposite one another and substantially parallel to the plane. A first electroactive layer is arranged together with a first deformable element on its rear face, and a second electroactive layer, different from the first layer, is arranged with a second deformable element, different from the first element, on its front face.

A transducer includes a supporting body and a suspended structure mechanically coupled to the supporting body. The suspended structure has a first and a second surface opposite to one another along an axis, and is configured to oscillate in an oscillation direction having at least one component parallel to the axis. A first piezoelectric transducer is disposed on the first surface of the suspended structure, and a second piezoelectric transducer is disposed on the second surface of the suspended structure.

A piezoelectric device includes a substrate, a thermal oxide layer on the substrate, a metal or metal oxide adhesion layer on the thermal oxide layer, a lower electrode on the metal oxide adhesion layer, a seed layer on the lower electrode, a lead magnesium niobate-lead titanate (PMNPT) piezoelectric layer on the seed layer, and an upper electrode on the PMNPT piezoelectric layer.

A design process is used for designing a device comprising a plurality of micro-machined elements, each comprising a flexible membrane, the elements being arranged in a plane in a determined topology. The design process comprises a step of defining the determined topology so that it has a character compatible with a generic substrate having cavities, the characteristics of which are pre-established. Each flexible membrane of the micro-machined elements is associated with one cavity of the generic substrate. The present disclosure also relates to a fabrication process for fabricating a device comprising a plurality of micro-machined elements, and to this device itself, wherein only some of the pairs of cavities and flexible membranes are configured to form a set of functional micro-machined elements.