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Assignee1...Limited
InventorsGareth McKevitt, Anthony Hooley, David Henry Pearce, Ursula Ruth Lenel, Mark Richard Shepherd
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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.
A sensor comprising an electro-active device electrically connected to a detector circuit, the electro-active device comprising an electro-active structure which extends along a curved minor axis and arranged, on activation by relative displacement of the ends of the structure, for the structure concomitantly to twist around the minor axis, the electro-active structure comprising electro-active portions disposed successively along the minor axis and arranged to be mechanically activated by being bent around the minor axis concomitantly with said twisting of the electro-active structure around the minor axis to generate an electrical signal, the detector circuit being arranged to detect the generated electrical signal.
Dependencies are inferred from the claim text.