A composition includes a polyrotaxane (A) which includes cyclodextrin as a ring molecule and polyethylene glycol as a linear molecule, and in which a blocking group is arranged at both ends of the linear molecule; a block copolymer (B) including polysiloxane; and a polymer (C) including no polysiloxane.

In some embodiments, the present invention is directed to an exemplary inventive method having steps of: providing at least one housing having a pre-determined physical structure; fixing a first edge of at least one electro-active polymer (EAP) film within the at least one housing; connecting a first edge of at least one pulling mechanism to a second edge of the at least one EAP film; where a second edge of the at least one pulling mechanism extends outside of the at least one housing; sufficiently pulling at the second edge of the at least one pulling mechanism to form at least one pre-stretched EAP film that has been stretched in a first axial direction within the at least one housing by a first pre-determined, pre-stretched amount; and where the pre-determined, pre-stretched amount is limited by the pre-determined physical structure of the housing.

A dielectric elastomer including a crosslinked network comprising a polypropylene oxide) unit on a network chain or a pendant group. In another example, the dielectric elastomer is stacked in a multi-layer dielectric elastomer structure comprising two adjacent dielectric elastomer layers, a layer of a. conductive network sandwiched between the two adjacent dielectric elastomer layers, and. a polymer layer binding the conductive network and the two adjacent dielectric elastomer layers. The dielectric elastomer can be used as an actuator or artificial muscle in a variety of robotic, haptic, or wearable devices. In one or more examples, the dielectric elastomer has a strain, including an area strain, greater than least 100% in response to the electric field less than 150 Volts per micron and converts at least 10% of inputted electrical energy to mechanical work.

To reduce the driving loss in the diaphragm, and to ensure a good sound output in the wide bandwidth. It includes a circular coil bobbin at least partly disposed between a yoke and a magnet, a coil wound around the coil bobbin, the coil being configured to be moved with the coil bobbin where a driving current is supplied to the coil, a piezoelectric element having one end coupled to one end of the coil bobbin in a movement direction, the piezoelectric element being configured to be expanded and contracted and moved in a direction same as the movement direction where an electric current is supplied to the piezoelectric element, and a diaphragm having an inner circumference part coupled to another end of the piezoelectric element, and a coupled part of the diaphragm to the piezoelectric element and a coupled part of the piezoelectric element to the coil bobbin are positioned on a straight line in the movement direction.

A piezoelectric transformer is disclosed In an embodiment a piezoelectric transformer includes a cylindrical base body with an input region and an output region, wherein a cylinder axis of the base body extends in a longitudinal direction, wherein the input region is configured to convert an AC voltage into a mechanical vibration, wherein the output region is configured to convert a mechanical vibration into an electrical voltage, wherein the output region includes a single piezoelectric layer polarized in the longitudinal direction, wherein, in the input region, a first piezoelectric layer, on which a first internal electrode is arranged, and a second piezoelectric layer, on which a second internal electrode is arranged, are wound onto one another, and wherein the first piezoelectric layer and the second piezoelectric layer are polarized in a radial direction which is perpendicular to the longitudinal direction.

The invention relates to actuators based on electroactive polymeric materials for use in pumping fluids or in other applications where a contractile actuation is required, in particular, although not necessarily exclusively, for use in vascular pulsation devices such as a variable aortic tension device. Embodiments disclosed include an actuator comprising: an inner tubular structure; an outer tubular structure surrounding the inner tubular structure and comprising a plurality of layers of a dielectric elastomeric material and a tubular elastic support structure, the elastic support structure configured to maintain a pre-stress in the layers of the dielectric elastomeric material, wherein the outer tubular structure is configured to contract in a radial direction around the inner tubular structure upon application of an actuation voltage signal across the dielectric elastomeric material layers.

The present application relates to stacked piezoelectric composites comprising piezoelectric structures. Suitably, the composites are useful as tissue-stimulating implants, including spinal fusion implants. The present application also relates to methods of making stacked piezoelectric composites.

A helical dielectric elastomer actuator (HDEA) can include a first dielectric region comprising an elastomer defining a helix. In an example, a dielectric material can be deposited and a compliant conductive material can be deposited, such as using an additive manufacturing approach, to provide an HDEA. In an example where the HDEA has multiple mechanical degrees of freedom, at least two compliant conductive regions can be located on a first surface of the first dielectric region and at least one compliant conductive region can be located on an opposite second surface of the first dielectric region. For such an example, the at least two compliant conductive regions can be arranged to be energized with respect to the at least one compliant conductive region in a manner providing at least two mechanical degrees of freedom for operation of the HDEA.

An actuator device comprises an electroactive or photoactive polymer arrangement having an effective length over which expansion or contraction is induced by actuation. The effective length is greater than the maximum linear physical dimension of the space occupied by the polymer arrangement. In this way, a compact design is provided which can support a large actuation displacement.

Embodiments of the present disclosure provide techniques and configurations for a robotic apparatus with an actuator formed by multiple fibers, in accordance with some embodiments. In some instances, the robotic apparatus may include an actuator to cause a motion of a component of a robot. The actuator may include at least one fiber that may comprise a conductive pattern. The conductive pattern may be embedded in a sheet of elastic material formed into a layered structure. The fiber may expand or contract in response to an application of a voltage signal to the conductive pattern, to cause the motion of the component of the robot. The fiber may comprise multiple fibers combined in a bundle, to form the actuator. The layered structure may comprise a roll-like shape that may be free of hollow spaces. In embodiments, the robot may comprise the robotic apparatus. Other embodiments may be described and/or claimed.