In a reservoir element that has a plurality of vibrators, at least one of the plurality of vibrators has a vibration state that is different from the vibration states of the other vibrators. The vibrations of the plurality of vibrators are configured to affect each other.

Various embodiments may provide an electromechanical responsive film. The electromechanical responsive film may include a composition including sodium (Na), potassium (K), niobium (Nb) and oxygen (O). The composition may have a formula (Na.sub.xK.sub.y)NbO.sub.3-δ, wherein 0≤x<1, wherein 0≤y<1, and wherein 0<x+y<1. The composition may satisfy at least one condition selected from a group consisting of a first condition of (x+y+4)/2≤(3−δ)≤(x+y+5)/2 and a second condition of 0<δ<1.

Provided is an apparatus for generating direct current using continuous polarization change of piezoelectric materials. For example, a piezoelectric direct current generator includes a first electrode, a polarized piezoelectric material layer disposed on a first surface of the first electrode, and a second electrode disposed on a surface opposite to the first electrode and coupled to move along the piezoelectric material layer while pressing the piezoelectric material layer.

A piezoelectric drive element disposed on a placement surface of a metal substrate includes a piezoelectric drive body having a first main surface opposite the placement surface, a second main surface on a placement surface side, and a side surface, and a first electrode disposed on the first main surface. The piezoelectric drive element is disposed on the placement surface such that a part of the placement surface is located outside the side surface. A second bonding member having conductivity includes a first portion disposed between the placement surface and the piezoelectric drive element, and a second portion being continuous from the first portion and disposed in a corner formed by the part of the placement surface and the side surface. The second portion does not reach the first electrode.

An actuator device includes a wiring substrate; a metal substrate; a first electrode unit provided to the metal substrate; a piezoelectric drive body disposed on the first electrode unit; a second electrode unit disposed on a first main surface of the piezoelectric drive body; a piezoelectric detection body disposed on the second electrode unit; a third electrode unit disposed on a third main surface of the piezoelectric detection body; a connection unit; an input unit; and an output unit. The connection unit is configured to be electrically connected to a reference potential on an outside such that a potential of the second electrode unit becomes the reference potential. The input unit is configured to input a drive signal to the first electrode unit from the outside. The output unit is configured to output an output signal generated in the piezoelectric detection body, to the outside from the third electrode unit.

A force-measuring device (FMD) assembly for a portable electronic apparatus includes a mid-frame including a base portion, a sidewall portion, and a transition region between the base portion and the sidewall portion, and force-measuring devices coupled to the inner surface of the sidewall portion. The sidewall portion and the transition region are elongate along a longitudinal axis. FMDs are coupled to the inner surface at respective contact regions of the sidewall portion and are separated from each other along the longitudinal axis. Each of the FMDs includes strain-sensing element(s). Each of the FMDs corresponds to a respective sense region of the sidewall portion. The transition region includes a respective elongate slit or trough for each of the sense regions. The respective elongate slit or trough is elongate along the longitudinal axis. Adjacent elongate slits or troughs are separated by a respective rib.

An electronic component includes a support member, a piezoelectric film, and an interdigital transducer. The support member includes silicon as a primary component. The piezoelectric film is provided directly or indirectly on the support member. The interdigital transducer includes a plurality of electrode fingers. The plurality of electrode fingers are provided side by side separately from each other. The interdigital transducer is provided on the principal surface of the piezoelectric film. The film thickness of the piezoelectric film is about 3.5 λ or less, where λ denotes the wavelength of an acoustic wave determined by the electrode finger pitch of the interdigital transducer. In the support member, the high-impurity-concentration region is further from the piezoelectric film than the low-impurity-concentration region.

A flexible vibration module is disclosed. The flexible vibration module includes a piezoelectric composite layer, including: a plurality of piezoelectric portions each having a piezoelectric characteristic, where at least two of the plurality of piezoelectric portions have different sizes; and a flexible portion between the plurality of piezoelectric portions.

Bulk acoustic wave (BAW) resonators, and particularly top electrodes with step arrangements for BAW resonators are disclosed. Top electrodes on piezoelectric layers are disclosed that include a border (BO) region with a dual-step arrangement where an inner step and an outer step are formed with increasing heights toward peripheral edges of the top electrode. Dielectric spacer layers may be provided between the outer steps and the piezoelectric layer. Passivation layers are disclosed that extend over the top electrode either to peripheral edges of the piezoelectric layer or that are inset from peripheral edges of the piezoelectric layer. Piezoelectric layers may be arranged with reduced thickness portions in areas that are uncovered by top electrodes. BAW resonators as disclosed herein are provided with high quality factors and suppression of spurious modes while also providing weakened BO modes that are shifted farther away from passbands of such BAW resonators.

An actuator assembly includes a primary electrode, a secondary electrode overlapping at least a portion of the primary electrode, and an electroactive polymer layer disposed between the primary electrode and the secondary electrode, where the electroactive polymer layer includes a non-vertical (e.g., sloped) sidewall with respect to a major surface of at least one of the electrodes. The electroactive polymer layer may be characterized by a non-axisymmetric shape with respect to an axis that is oriented orthogonal to an electrode major surface.