Example implementations of a bulk acoustic wave resonator with an optimized outer perimeter are disclosed. In an example aspect, a resonator includes a truncated-ellipsoid-shaped active region. The active region includes an outer electrode disposed as a first layer of the active region. The active layer also includes a piezoelectric layer disposed as a second layer of the active region with the piezoelectric layer disposed interior to the outer electrode. The active layer further includes an inner electrode disposed as a third layer of the active region with the inner electrode disposed interior to the piezoelectric layer.

A MEMS device is provided that includes a semiconductor substrate including a main surface extending perpendicular to a first direction and a side surface extending on a plane parallel to the first direction and to a second direction that is perpendicular to the first direction. At least one cantilevered member protrudes from the side surface of the semiconductor substrate along a third direction that is perpendicular to the first and second directions. The at least one cantilevered member includes a body portion that includes a piezoelectric material. The body portion has a length along the third direction, a height along the first direction and a width along the second direction, and the height is greater than the width. The at least one cantilevered member is configured to vibrate by lateral bending along a direction perpendicular to the first direction.

A MEMS device is provided that includes a semiconductor substrate including a main surface extending perpendicular to a first direction and a side surface extending on a plane parallel to the first direction and to a second direction that is perpendicular to the first direction. At least one cantilevered member protrudes from the side surface of the semiconductor substrate along a third direction that is perpendicular to the first and second directions. The at least one cantilevered member includes a body portion that includes a piezoelectric material. The body portion has a length along the third direction, a height along the first direction and a width along the second direction, and the height is greater than the width. The at least one cantilevered member is configured to vibrate by lateral bending along a direction perpendicular to the first direction.

The present invention relates to a method to fabricate a tamper respondent assembly. The tamper respondent assembly includes an electronic component and an enclosure fully enclosing the electronic component. The method includes printing, by a 3-dimensional printer, a printed circuit board that forms a bottom part of the enclosure and includes a first set of embedded detection lines for detecting tampering events and signal lines for transferring signals between the electronic component and an external device. The electronic component is assembled on the printed circuit board, and a cover part of the enclosure is printed on the printed circuit board. The cover part includes a second set of embedded detection lines. Sensing circuitry can be provided for sensing the conductance of the first set of embedded detection lines and the second set of embedded detection lines to detect tampering events.

In some embodiments, the present disclosure relates to a method in which a first set of one or more voltage pulses is applied to a piezoelectric device over a first time period. During the first time period, the method determines whether a performance parameter of the piezoelectric device has a first value that deviates from a reference value by more than a predetermined value. Based on whether the first value deviates from the reference value by more than the predetermined value, the method selectively applies a second set of one or more voltage pulses to the piezoelectric device over a second time period. The second time period is after the first time period and the second set of one or more voltage pulses differs in magnitude and/or polarity from the first set of one or more voltage pulses.

In some embodiments, the present disclosure relates to a method in which a first set of one or more voltage pulses is applied to a piezoelectric device over a first time period. During the first time period, the method determines whether a performance parameter of the piezoelectric device has a first value that deviates from a reference value by more than a predetermined value. Based on whether the first value deviates from the reference value by more than the predetermined value, the method selectively applies a second set of one or more voltage pulses to the piezoelectric device over a second time period. The second time period is after the first time period and the second set of one or more voltage pulses differs in magnitude and/or polarity from the first set of one or more voltage pulses.

A piezoelectric microelectromechanical system microphone has a piezoelectric sensor layer with at least two sensing electrodes and at least one piezoelectric layer. Each piezoelectric layer can deform and generate an electrical potential responsive to impingement of sound waves on the piezoelectric layer. The sensing electrodes and the at least one piezoelectric layer form a stacked electrode structure. Each sensing electrode is disposed on or below a corresponding piezoelectric layer and senses the generated electrical potential. At least one of the sensing electrodes can include first corrugations which are configured such to release residual stress and to improve sensitivity of the microelectromechanical system microphone.

A piezoelectric microelectromechanical system microphone has a piezoelectric sensor layer with at least two sensing electrodes and at least one piezoelectric layer. Each piezoelectric layer can deform and generate an electrical potential responsive to impingement of sound waves on the piezoelectric layer. The sensing electrodes and the at least one piezoelectric layer form a stacked electrode structure. Each sensing electrode is disposed on or below a corresponding piezoelectric layer and senses the generated electrical potential. At least one of the sensing electrodes can include first corrugations which are configured such to release residual stress and to improve sensitivity of the microelectromechanical system microphone.

A product includes an array of cold spray-formed structures. Each of the structures is characterized by having a defined feature size in at least one dimension of less than 100 microns as measured in a plane of deposition of the structure, at least 90% of a theoretical density of a raw material from which the structure is formed, and essentially the same functional properties as the raw material. A product includes a cold spray-formed structure characterized by having a defined feature size in at least one dimension of less than 100 microns as measured in a plane of deposition of the structure, at least 90% of a theoretical density of a raw material from which the structure is formed, and essentially the same functional properties as the raw material.

A product includes an array of cold spray-formed structures. Each of the structures is characterized by having a defined feature size in at least one dimension of less than 100 microns as measured in a plane of deposition of the structure, at least 90% of a theoretical density of a raw material from which the structure is formed, and essentially the same functional properties as the raw material. A product includes a cold spray-formed structure characterized by having a defined feature size in at least one dimension of less than 100 microns as measured in a plane of deposition of the structure, at least 90% of a theoretical density of a raw material from which the structure is formed, and essentially the same functional properties as the raw material.