A method is provided for manufacturing a dielectric elastomer transducer including a dielectric elastomer layer and electrode layers sandwiching the elastomer layer. The elastomer layer when stretched exhibits a stress-strain curve having: a low strain and high elasticity region; a low elasticity region; and a high strain region. The method includes: a pre-stretching process to reduce hysteresis in elastic behavior of the elastomer layer by stretching the elastomer layer one or more times under a load as heavy as a first load before the electrodes are provided, each stretching causing the elastomer layer to undergo a tension falling in the low elasticity region; and a dielectric elastomer layer fixing process including applying a second load smaller than the first load to the elastomer layer so as to fix the elastomer layer to a support member under a second tension smaller than the first tension.

An example device includes a nanovoided polymer element, a first electrode, and a second electrode. The nanovoided polymer element may be located at least in part between the first electrode and the second electrode. In some examples, the nanovoided polymer element may include anisotropic voids. In some examples, anisotropic voids may be elongated along one or more directions. In some examples, the anisotropic voids are configured so that a polymer wall thickness between neighboring voids is generally uniform. Example devices may include a spatially addressable electroactive device, such as an actuator or a sensor, and/or may include an optical element. A nanovoided polymer layer may include one or more polymer components, such as an electroactive polymer.

Provided are an electroacoustic conversion film and an electroacoustic converter which are capable of suppressing a decrease in piezoelectric conversion efficiency in a case of use in a high-temperature environment. The electroacoustic conversion film is an electroacoustic conversion film including a polymer-based piezoelectric composite material which contains piezoelectric particles in a matrix containing a polymer material, and electrode layers which are formed on both surfaces of the polymer-based piezoelectric composite material, in which the electroacoustic conversion film has a thermal expansion coefficient of 12 ppm/° C. to 100 ppm/° C.

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.

Methods of manufacturing high frequency ultrasound transducers configured for use with high frequency ultrasound diagnostic imaging systems are disclosed herein. In one embodiment, methods of manufacturing an ultrasound transducer includes providing a concave lens having an average thickness in a center portion that that is substantially equal to an odd multiple of a ¼-wavelength of the center frequency of the ultrasound transducer.

A system for passive damping of mechanical vibrations generated by a vibrating structure supported by a support, including a transducer interposed between the vibrating structure and the support to transform mechanical energy of vibrations into electrical energy. The transducer includes a flextensional structure having a first axis perpendicular to a second axis, a stack of piezoelectric elements adapted to produce electrical energy when stressed, the stack stressed in compression by the flextensional structure along the first axis so that deformation of the structure modifies the compressive stress applied to the stack, two peripheral fasteners are secured to the flextensional structure, each fastener disposed along the second axis, a first fastener for securing the flextensional structure to the vibrating structure, a second fastener for securing the flextensional structure to the support, at least one fastener integrates an elastic suspension, a shunt connected to the piezoelectric stack to dissipate electrical energy.

Embodiments of the disclosure are generally directed to systems and methods for switchable electroactive devices for head-mounted displays (HMDs). In particular, a method may include (1) applying an electric field to an electroactive element of an electroactive device via electrodes of the electroactive device that are electrically coupled to the electroactive element to compress the electroactive element, which comprises a polymer material defining nanovoids, such that an average size of the nanovoids is decreased and a density of the nanovoids is increased in the electroactive element, wherein the electroactive device is positioned at a distance from a user's eye, and (2) emitting image light from an emissive device positioned such that at least a portion of the image light is incident on a surface of the electroactive device facing the user's eye.

A device and method for producing said device comprising an improved ultrasonic biometric sensor is disclosed. The ultrasonic biometric sensor is composed of a pixel array and multiple copolymer layers which are polarized in such a fashion as to increase the transmitting pressure and receiving sensitivity of the sensor. The copolymer layers may be polarized in the same direction, or in opposite directions, depending on the desired functionality.

An optical element includes a primary electrode, a secondary electrode overlapping at least a portion of the primary electrode, and a structurally-modified and transparent electroactive polymer disposed between and abutting the primary electrode and the secondary electrode. An optical device may include a tunable lens and an optical element disposed over at least one surface of the tunable lens.

An example device includes a nanovoided polymer element, which may be located at least in part between the electrodes. In some examples, the nanovoided polymer element may include anisotropic voids, including a gas, and separated from each other by polymer walls. The device may be an electroactive device, such as an actuator having a response time for a transition between actuation states. The gas may have a characteristic diffusion time (e.g., to diffuse half the mean wall thickness through the polymer walls) that is less than the response time. The nanovoids may be sufficiently small (e.g., below 1 micron in diameter or an analogous dimension), and/or the polymer walls may be sufficiently thin, such that the gas interchange between gas in the voids and gas absorbed by the polymer walls may occur faster than the response time, and in some examples, effectively instantaneously.