Packaged strain actuator
First Claim
1. An electro-active device comprising a plurality of flex circuits, each having a sheet of film and an electrode on at least one surface of the film, said plurality including at least first and second flex circuits, means forming a recess between said first and second flex circuits, and an electro-active element in said recess bonded to the flex circuits being mechanically and electrically coupled thereto.
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Accused Products
Abstract
A modular actuator assembly includes one or more plates or elements of electro-active material bonded to an electroded sheet, preferably by a structural polymer to form a card. The card is sealed, and may itself constitute a practical device, such as a vane, shaker, stirrer, lever, pusher or sonicator for direct contact with a solid or immersion in a fluid, or may be bonded by a stiff adhesive to make a surface-to-surface mechanical coupling with a solid workpiece, device, substrate, machine or sample. The structural polymer provides a bending stiffness such that the thin plate does not deform to its breaking point, and a mechanical stiffness such that shear forces are efficiently coupled from the plate to the workpiece. In further embodiments, the card may include active circuit elements for switching, powering or processing signals, and/or passive circuit elements for filtering, matching or damping signals, so that few or no connections to outside circuitry are required. The actuator assembly can be manufactured in quantity, to provide a versatile actuator with uniform mechanical and actuation characteristics, that introduces negligible mass loading to the workpiece. The cards themselves may be arranged as independent mechanical actuators, rather than strain-transfer actuators, in which the induced strain changes the position of the card. Various arrangements of pinned or cantilevered cards may act as a pusher, bender or other motive actuator, and structures such as powered bellows may be formed directly by folding one or more suitably patterned cards.
5 Citations
31 Claims
- 1. An electro-active device comprising a plurality of flex circuits, each having a sheet of film and an electrode on at least one surface of the film, said plurality including at least first and second flex circuits, means forming a recess between said first and second flex circuits, and an electro-active element in said recess bonded to the flex circuits being mechanically and electrically coupled thereto.
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19. An actuator comprising
a flex circuit having conductors, and a sheet strain element wherein the flex circuit is assembled with at least some of its conductors in electrical contact with the sheet strain element and is bonded together therewith by a structural polymer into a flat card having an output face with a substantially shear-free mechanical coupling to the flat strain element.
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20. A method of perturbing a device, such method comprising the steps of
(i) cementing a card in contact with a region of the device, the card enclosing a sheet of electro-active ceramic material with actuation electrodes, and (ii) applying an electrical signal to the actuation electrodes to create strain energy in the electro-active ceramic material, whereby the strain energy from the electro-active ceramic material is coupled across a face of the card into said region to perturb the device.
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21. A method of forming an actuator, such method comprising the steps of
forming a flex circuit having conductors arranged in a pattern bonding an electro-active ceramic sheet in contact with at least some of said conductors, and assembling the flex circuit and the electro-active ceramic sheet with a stiff structural polymer so as to constitute a card such that the sheet has a non-shear coupling to an outer face of the card and is electrically coupled over a region to electrodes of said flex circuit.
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23. A method of forming an electro-active device, such method comprising the step of:
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preparing first and second flex circuits with first and second electrodes and a recess therebetween, and bonding at least one electro-active element in the recess in mechanical and electrical contact with said flex circuits over its surface area to form a unitary electro-active structure.
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Specification