Abstract: An electrospray emitter (10) for emitting a liquid comprising a sheet (40) having a channel (65) opening to an aperture (55) on a flat emitter surface extending across the sheet (40). A charging electrode (80) coupleable to an electrical supply and arranged to apply an electrical charge to liquid passing into the channel (65). A control electrode (50) proximal to the channel (65) for controlling electrospray emission, that may be embedded in the sheet. A non-wetting or insulating layer (30) may be applied to the sheet.

Abstract: An electrospray emitter (10) for emitting a liquid comprising a sheet (40) having a channel (65) opening to an aperture (55) on a flat emitter surface extending across the sheet (40). A charging electrode (80) coupleable to an electrical supply and arranged to apply an electrical charge to liquid passing into the channel (65). A control electrode (50) proximal to the channel (65) for controlling electrospray emission, that may be embedded in the sheet. A non-wetting or insulating layer (30) may be applied to the sheet.

Abstract: A piezoelectric device comprising a continuous piezoelectric element (10) extending alternately back and forth to form a plurality of parallel, straight portions (14) arranged in a stack with intermediate linkage portions (15) at alternate ends of the straight portions (14). Each straight portion (14) is constructed and arranged with electrodes (12, 13) to bend, on activation, in the stacking direction in which the straight portions (14) are stacked with opposite curvature in two halves (16, 17) of the straight portion (14) to create displacement between the ends of the straight portion (14) in the stacking direction adding in series through the stack. The continuous nature of the piezoelectric element (10) eases manufacture. Devices with two types of construction are disclosed. Firstly, the continuous piezoelectric element (10) may have a bender construction such as a bimorph bender construction.

Abstract: A variable focal length lens, comprises a chamber arrangement containing two transparent liquids adjacent one another with an interface therebetween, the chamber arrangement allowing light to pass along an optical axis through the transparent liquids and across the interface, the lens focusing the passing light. A piezoelectric actuator is arranged, on activation, to change the pressure of one of the liquids so that the interface moves, for example by changing shape, to change the focal length of the lens.

Abstract: A loudspeaker for audible sound is described having a sound emitting element mounted onto a support structure and at least one actuator adapted to rotate said sound emitting element around a hinge section, wherein the actuator is made of piezoelectric material. In variants the actuator forms part of the hinge section and the loudspeaker is capable of generating vibrations through its support structure.

Abstract: An example housing that protects a ceramic actuator from excessive and damaging displacement comprises a protective structure arranged to limit the motion of the actuator by contacting at least one section of the actuator between fixed and moving terminals of said actuator. A suspension system for a lens holder of a miniature camera actuated by a ceramic actuator comprises four pivotally connected link elements in form of a parallelogram connected between a housing and the lens holder.

Abstract: A loudspeaker comprising: a support, a sound-generating element mounted to the support for vibration to generate sound; and an electro-active device coupled between the support and the sound-generating element for vibrating the sound-generating element in response to an electrical signal. The electro-active device comprises a structure extending along a minor axis which extends in a curve around a major axis parallel to the vibration direction of the sound-generating element, the structure comprising successive electro-active portions arranged with electrodes to bend around the minor axis on activation in response to application of the electrical signal to the electrodes, and coupled together such that bending of successive portions causes concomitant rotation of adjacent portions around the minor axis adding incrementally along the minor axis, which rotation causes concomitant change of the axial length of the structure along the major axis.

Abstract: An equivalent to the spatial separation either side of a nominal median plane that is inherent in a bimorph (with one piezoelectric layer on one side, and the second on the other side of the plane) is attained by structurally shaping the cross-section of a simple, single piezoelectric layer (11) such that it has a multiplicity of piezoelectric portions arranged in two generally-planar groups one either side of a median plane, so that any dimension change undergone by a portion on one side of that plane will tend to bend the whole device in the opposite direction to the same sense dimension change undergone by a portion on the other side of that plane. The simple, single layer acts as though it were a bimorph if elongate and beam-like, bending along its length, one end moving up/down, or back/forth, relative to the other but with any need for an internal, electrode.

Abstract: Electro-active actuators (310) and methods of manufacturing such actuators are described with such actuators (310) having a plurality of electro-active segments (311) arranged along a curved line with each segment (311) being essentially planar and coupled to adjacent segments (311) through joint sections (312) placed at opposite corners of the segment (311). The actuators (310) exhibit a displacement in a different direction than the direction of displacement of a segment when seen in isolation. They can be made from a continuous tape of material, preferably by die punching.

Abstract: Various sensors use an electro-active device (11) electrically connected to a detector circuit. The electro-active device (11) comprises an electro-active structure in the form of a continuous electro-active member (12) curving in a helix around a minor axis (13) which is in itself curved for example in a helix around a major axis (14). On activation by relative displacement of the ends (16) of the device (11), the electro-active structure twists around the minor axis due to the fact that the minor axis (13) is curved. The continuous member (12) has a bender construction of a plurality of layers (21) and (22) including at least one layer of electro-active material so that concomitantly with the twisting the continuous member (12) bends generating an electrical signal detected by the detector circuit. The electro-active device (11) is advantageous as a sensing element in a sensor because it has a large displacement, high sensitivity and low compliance.

Abstract: A multi-channel array droplet deposition apparatus has a base sheet comprising a layer of piezo-electric material poled normal thereto, an array of parallel, open-topped droplet liquid channels provided by upstanding channel separating walls formed in the layer, electrodes on channel facing surfaces of the walls, a channel closure sheet bonded to the walls, nozzles respectively communicating with the channels and a droplet liquid supply connecting with the channels, the closure sheet having an array of parallel conductive tracks thereon paced at intervals corresponding with the channel spacing and located parallel to and opposite the channels and bonds, which preferably are solder bonds, mechanically and electrically connect each track to the electrodes of the channel facing walls of the channels opposite thereto and seal the closure sheet to the channels.

Abstract: The present invention relates to an electro-active device having an electro-active structure extending along a minor axis (36) which is curved, for example in a helix around a major axis (37). The electro-active structure comprises successive electro-active portions (35) extending around said minor axis and arranged with electrodes to bend, when activated, around the minor axis (36) such that bending of the successive portions (35) is concomitant with rotation of the electro-active structure about the minor axis (36) adding incrementally along the minor axis (36). The electro-active structure generates displacement out of the local plane in which the minor axis is curved. The electra-active structure may be continuous electro-active member (35) extending along and curving around the minor axis (35), for example helically to form a helical helix. Alternatively, the electro-active structure may be a plurality of discrete elements (211) connected together.

Abstract: Various sensors use an electro-active device (11) electrically connected to a detector circuit. The electro-active device (11) comprises an electro-active structure in the form of a continuous electro-active member (12) curving in a helix around a minor axis (13) which is in itself curved for example in a helix around a major axis (14). On activation by relative displacement of the ends (16) of the device (11), the electro-active structure twists around the minor axis due to the fact that the minor axis (13) is curved. The continuous member (12) has a bender construction of a plurality of layers (21) and (22) including at least one layer of electro-active material so that concomitantly with the twisting the continuous member (12) bends generating an electrical signal detected by the detector circuit. The electro-active device (11) is advantageous as a sensing element in a sensor because it has a large displacement, high sensitivity and low compliance.

Abstract: A loudspeaker for audible sound is described having a sound emitting element mounted onto a support structure and at least one actuator adapted to rotate said sound emitting element around a hinge section, wherein the actuator is made of piezoelectric material. In variants the actuator forms part of the hinge section and the loudspeaker is capable of generating vibrations through its support structure.

Abstract: The present invention relates to an electro-active device having an electro-active structure extending along a minor axis (36) which is curved, for example in a helix around a major axis (37). The electro-active structure comprises successive electro-active portions (35) extending around said minor axis and arranged with electrodes to bend, when activated, around the minor axis (36) such that bending of the successive portions (35) is concomitant with rotation of the electro-active structure about the minor axis (36) adding incrementally along the minor axis (36). The electro-active structure generates displacement out of the local plane in which the minor axis is curved. The electro-active structure may be continuous electro-active member (35) extending along and curving around the minor axis (35), for example helically to form a helical helix. Alternatively, the electro-active structure may be a plurality of discrete elements (211) connected together.

Abstract: The present invention relates to a loudspeaker (480), comprising: a support (483); a sound-generating element (481) mounted to the support for vibration to generate sound; and an electro-active device (485) coupled between the support and the sound-generating element for vibrating the sound-generating element (481) in response to an electrical signal.

Abstract: The invention describes a method of forming a drop-on-demand printing apparatus having a body formed with a high density array of parallel channels (13) extending normal to the array direction, nozzles (27) connected respectively with the channels, printing liquid supply means with which said channels each communicate and pressure pulse applying means provided with each channel to apply pressure pulses to the channel liquid to effect droplet ejection, in which the body is formed by a plurality of like modules (2) serially butted together at facing end surfaces (49, 51) which are normal to the array direction, the arrangement enabling ejection of droplets from the channels so that said droplets are deposited on a printing surface at a predetermined spacing transversely to the direction of relative movement between the apparatus and said surface.