The present invention relates to a vacuum capacitor (1, 30) comprising an enclosure (9) to contain a vacuum dielectric medium, a first electrode (12) and a second electrode (13) separated by said vacuum dielectric medium, the enclosure (9) comprising a first conductive collar (2) in electrical contact with the first electrode (12) and a second conductive collar (3) in electrical contact with the second electrode (13), the first conductive collar (2) and the second conductive collar (3) being separated by an insulating element (4) of the enclosure (9), wherein the enclosure (9) exhibits at least one protruding edge (6), said protruding edge (6) being in electrical contact with the closest of the first conductive collar (2) or the second conductive collar (3), wherein the vacuum capacitor (1, 30) comprises at least one protection means (7, 37) covering on the outside of the vacuum enclosure the protruding edge (6), wherein the protection means (7, 37) is made at least partially of an elastomer, wherein at least the outer surface (7b, 37b) of the protection means (7, 37) is electrically conductive and is at the same electrical potential as the closest conductive collar to the protruding edge (6), and wherein the outer surface (7b, 37b) of the protection means (7, 37) has a radius of curvature greater than the radius of curvature of the protruding edge (6).

A manufacturing method for a magnetic head forms a leading shield having a top surface. The top surface of the leading shield includes first and second portions. The second portion is located farther from a medium facing surface than is the first portion, and recessed from the first portion. A first gap layer is then formed on the first portion. Then, a magnetic layer including an initial first side shield, an initial second side shield and a coupling section connecting them is formed using a mold. The mold is then removed. The coupling section is then removed by etching the magnetic layer. A second gap layer and a main pole are then formed in this order.

A vacuum variable capacitor includes a pre-vacuum enclosure for reducing a pressure differential across the bellows, wherein a drive is disposed outside the enclosures of the vacuum variable capacitor. The vacuum force load on the drive system can thereby be reduced, allowing faster movement of the movable electrode, faster capacitance adjustment of the vacuum variable capacitor and longer lifetimes of the device.

The present invention relates to a vacuum capacitor (1, 30) comprising an enclosure (9) to contain a vacuum dielectric medium, a first electrode (12) and a second electrode (13) separated by said vacuum dielectric medium, the enclosure (9) comprising a first conductive collar (2) in electrical contact with the first electrode (12) and a second conductive collar (3) in electrical contact with the second electrode (13), the first conductive collar (2) and the second conductive collar (3) being separated by an insulating element (4) of the enclosure (9), wherein the enclosure (9) exhibits at least one protruding edge (6), said protruding edge (6) being in electrical contact with the closest of the first conductive collar (2) or the second conductive collar (3), wherein the vacuum capacitor (1, 30) comprises at least one protection means (7, 37) covering on the outside of the vacuum enclosure the protruding edge (6), wherein the protection means (7, 37) is made at least partially of an elastomer, wherein at least the outer surface (7b, 37b) of the protection means (7, 37) is electrically conductive and is at the same electrical potential as the closest conductive collar to the protruding edge (6), and wherein the outer surface (7b, 37b) of the protection means (7, 37) has a radius of curvature greater than the radius of curvature of the protruding edge (6).

A micromachined ultrasonic transducer (MUT). The MUT includes: a substrate; a membrane suspending from the substrate; a bottom electrode disposed on the membrane; a piezoelectric layer disposed on the bottom electrode and an asymmetric top electrode is disposed on the piezoelectric layer. The areal density distribution of the asymmetric electrode along an axis has a plurality of local maxima, wherein locations of the plurality of local maxima coincide with locations where a plurality of anti-nodal points at a vibrational resonance frequency is located.

A micromachined ultrasonic transducer (MUT). The MUT includes: a substrate; a membrane suspending from the substrate; a bottom electrode disposed on the membrane; a piezoelectric layer disposed on the bottom electrode and an asymmetric top electrode is disposed on the piezoelectric layer. The areal density distribution of the asymmetric electrode along an axis has a plurality of local maxima, wherein locations of the plurality of local maxima coincide with locations where a plurality of anti-nodal points at a vibrational resonance frequency is located.

A micromachined ultrasonic transducer (MUT). The MUT includes: a substrate; a membrane suspending from the substrate; a bottom electrode disposed on the membrane; a piezoelectric layer disposed on the bottom electrode and an asymmetric top electrode is disposed on the piezoelectric layer. The areal density distribution of the asymmetric electrode along an axis has a plurality of local maxima, wherein locations of the plurality of local maxima coincide with locations where a plurality of anti-nodal points at a vibrational resonance frequency is located.

A micromachined ultrasonic transducer (MUT). The MUT includes: a substrate; a membrane suspending from the substrate; a bottom electrode disposed on the membrane; a piezoelectric layer disposed on the bottom electrode and an asymmetric top electrode is disposed on the piezoelectric layer. The areal density distribution of the asymmetric electrode along an axis has a plurality of local maxima, wherein locations of the plurality of local maxima coincide with locations where a plurality of anti-nodal points at a vibrational resonance frequency is located.

A micromachined ultrasonic transducer (MUT). The MUT includes: a substrate; a membrane suspending from the substrate; a bottom electrode disposed on the membrane; a piezoelectric layer disposed on the bottom electrode and an asymmetric top electrode is disposed on the piezoelectric layer. The areal density distribution of the asymmetric electrode along an axis has a plurality of local maxima, wherein locations of the plurality of local maxima coincide with locations where a plurality of anti-nodal points at a vibrational resonance frequency is located.

A micromachined ultrasonic transducer (MUT). The MUT includes: a substrate; a membrane suspending from the substrate; a bottom electrode disposed on the membrane; a piezoelectric layer disposed on the bottom electrode and an asymmetric top electrode is disposed on the piezoelectric layer. The areal density distribution of the asymmetric electrode along an axis has a plurality of local maxima, wherein locations of the plurality of local maxima coincide with locations where a plurality of anti-nodal points at a vibrational resonance frequency is located.