A synthetic jet pump and a method of pumping fluid using such a synthetic jet pump are disclosed. The synthetic jet pump includes a plurality of first stacks disposed in a series arrangement relative to each other, and a plurality of first valves. A first stack of the plurality of first stacks includes a plurality of first connector pairs coupled to a first support structure and a plurality of first bimorph pairs. The first connector pairs and the first bimorph pairs are disposed in a parallel arrangement relative to each other respectively. A bimorph of one of the first bimorph pairs is coupled to a corresponding first connector pair. The plurality of first valves is disposed at an upstream end of the plurality of first stacks. A valve of the plurality of first valves is movably coupled to a corresponding connector of the plurality of the first connector pairs.

A transducer (140) having a mechanical impedance over an operative frequency range and having a desired power coupling (145) to a load over the operative frequency range comprises a piezoelectric device (141) having a frequency distribution of modes in the operative frequency range; and an overmould (143). The overmould (143) is arranged to surround at least part of the piezoelectric device (141); and the parameters of the overmould (143) are selected to provide a required impedance matching between the mechanical impedance of the transducer (140) and the mechanical impedance of the load. An alternative transducer comprises a mounting means for holding a discrete portion of at least a part of the periphery of the piezoelectric device wherein the parameters of the mounting means are selected to provide a required boundary condition for the periphery of the piezoelectric device whereby the desired power coupling between the transducer and the load is provided.

A resonator is provided that suppresses frequency variations with etching without decreasing the strength of vibration arms. The resonator includes a base portion, a first vibration portion extending from the base portion in a first direction and having a first width, and a second vibration portion extending from the base portion in the first direction with a first gap between the first and second vibration portions and having the first width. The first and second vibration portions perform out-of-plane bending vibration with opposite phases at a predetermined frequency. The predetermined frequency varies in accordance with the first width and the first gap. The ratio of the first gap to the first width is within a range that causes an absolute value of rates of variations in the predetermined frequency with respect to variations in the first width and in the first gap to be not more than about 100 ppm.

Examples of portable electronic devices including a piezo actuated vibrator for providing tactile feedback to the user are described. Portable electronic devices according to the present disclosure may include tactile feedback devices, which may be driven by a piezoelectric actuator/vibrator that is operatively coupled to or embedded into the housing of a portable electronic device. In some examples, the housing of the electronic device itself can be made of piezoelectric ceramic material. The piezoelectric element may be coupled to the housing of the product to cause the housing to deflect and/or vibrate. In some examples, the housing of the portable electronic device, which may be a portable media player device, may be configured for placement directly or indirectly in contact with the user's skin such that vibrations of the housing may be felt directly (without audible feedback) by the user.

A vibrator device that includes a support member, first and second displacement plates, first and second piezoelectric vibrator elements, and an added mass member. The support member has first and second side portions opposing each other. The first displacement plate is supported by the first side portion and extends toward the second side portion so as to have a free end. The second displacement plate is supported by the second side portion and extends toward the first side portion so as to have a free end. The first and second piezoelectric vibrator elements are respectively disposed on the first and second displacement plates. The added mass member is connected to a portion of the first displacement plate at or around the free end thereof and to a portion of the second displacement plate at or around the free end thereof.

A fixed frame (2) is fixed to an external member. An ultrasonic oscillator (3) is disposed inside the fixed frame (2) and includes a flexible first substrate and a first piezoelectric element deposited on the first substrate in the form of a thin film. The ultrasonic oscillator (3) is warped in response to expansion or contraction of the first piezoelectric element and generates ultrasonic waves. Actuator units (4) include a flexible second substrate coupling the first substrate to the fixed frame (2) and a second piezoelectric element deposited on the second substrate in the form of a thin film. The actuator units (4) are warped in response to expansion or contraction of the second piezoelectric element and cause the ultrasonic oscillator (3) to swing relative to the fixed frame (2). The fixed frame (2), the first substrate, and the second substrate are composed of the same substrate.

A resonance device is provided with a reduced size and also suppresses the occurrence of deformation and breakage during operation. The resonance device includes a lower substrate, an upper substrate that defines a vibration space between the lower substrate and the upper substrate, a protruding portion that is formed on an inner surface of the lower or upper substrates. Moreover, a resonator is disposed in the vibration space and includes a base portion and vibration arms that extend in parallel to one another from the base portion along the inner surface of the lower substrate or the inner surface of the upper substrate and that vibrate in a vertical direction toward the inner surface of the lower substrate or the inner surface of the upper substrate.

An array of micromachined ultrasonic transducers (MUTs). The array has first and second rows, the MUTs in the first row being equally spaced by a horizontal pitch in a horizontal direction, the MUTs in the second row being equally spaced by the horizontal pitch in the horizontal direction. The MUTs in the second row are shifted along the horizontal direction by a first horizontal distance relative to the MUTs in the first row and shifted along a vertical direction by a first vertical distance relative to the MUTs in the first row. The first horizontal distance is greater than zero and less than the horizontal pitch. The first vertical distance ranges from one tenth of a horizontal width of a MUT to a half of a vertical height of a MUT.

An ultrasonic water jet apparatus includes a water accumulation part in which the water supplied from a water supply source is temporarily accumulated, a jet port that jets the water accumulated in the water accumulation part, and a piezoelectric vibration plate including a dome part that is disposed opposed to the jet port in the water accumulation part and propagates the ultrasonic vibration to the water accumulated in the water accumulation part, a flange part that projects outward in the radial direction from a peripheral edge of the dome part, and an annular plate that projects outward in the radial direction from a peripheral edge of the flange part.

According to various embodiments, a PMUT device may include a wafer, an active layer including a piezoelectric stack, an intermediate layer having a cavity therein where the intermediate layer is disposed between the wafer and the active layer such that the cavity is adjoining the piezoelectric stack. A via may be formed through the active layer and the intermediate layer to the wafer. A metallic layer may be disposed over the active layer and over surfaces of the via. The intermediate layer may include an interposing material surrounding the cavity, and may further include a sacrificial material surrounding the via. The sacrificial material may be different from the interposing material. The metallic layer may include a first member at least substantially overlapping the piezoelectric stack, a second member extending from the first member to the cavity, and a third member extending into the active layer to contact an electrode therein.