Tactile sensors
First Claim
1. A tactile sensor capable of determining a direction from which a force is applied, comprising:
- (a) an electroactive polymer comprising;
(i) an ion-exchange membrane formed into a convex dome having an outer surface and an inner surface;
(ii) a plurality of flexible electrodes disposed on the outer surface of the ion-exchange membrane, so that each of the plurality of flexible electrodes covers a different circumferential segment of the outer surface of the convex dome; and
(iii) a base flexible electrode disposed on the inner surface of the ion-exchange membrane;
(b) a plurality of electrical conductors that are electrically connected to the plurality of flexible electrodes and to the base flexible electrode to convey output signals from the plurality of flexible electrodes and the base flexible electrode, wherein distortion of a segment of the ion-exchange membrane caused by a force applied to the flexible electrode covering the segment causes the segment of the ion-exchange membrane to produce an output signal indicative of a magnitude of the force, wherein relative differences in the output signals conveyed from the flexible electrodes covering the different segments of the convex dome are further indicative of a direction of the force acting on the tactile sensor; and
(c) an elastomeric support disposed within a concave cavity formed under the convex dome, the elastomeric support preventing a force applied against one or more of the plurality of flexible electrodes from inverting the ion-exchange membrane.
3 Assignments
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Accused Products
Abstract
An electroactive polymer is used to produce a tactile sensor. The electroactive polymer (EAP) includes a sheet of an ion-exchange membrane having opposite surfaces on which are plated gold electrodes. The EAP is formed to have a dome-shape with a plurality of sensing electrodes circumferentially disposed around an outer surface of the dome. A flexible polymer underlying the EAP supports it and prevents a force applied to the tactile sensor from inverting the dome. The sensor electrodes produce separate output signals indicative of different vector components of an applied force acting on the tactile sensor, so that a direction of the force can be determined. Vias provided in the electrodes are electrically coupled to a flexible circuit that conveys the output signals externally from the sensing electrodes for use and further processing. A plurality of the tactile sensors can be formed as an array on an ion-exchange membrane.
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Citations
33 Claims
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1. A tactile sensor capable of determining a direction from which a force is applied, comprising:
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(a) an electroactive polymer comprising; (i) an ion-exchange membrane formed into a convex dome having an outer surface and an inner surface; (ii) a plurality of flexible electrodes disposed on the outer surface of the ion-exchange membrane, so that each of the plurality of flexible electrodes covers a different circumferential segment of the outer surface of the convex dome; and (iii) a base flexible electrode disposed on the inner surface of the ion-exchange membrane; (b) a plurality of electrical conductors that are electrically connected to the plurality of flexible electrodes and to the base flexible electrode to convey output signals from the plurality of flexible electrodes and the base flexible electrode, wherein distortion of a segment of the ion-exchange membrane caused by a force applied to the flexible electrode covering the segment causes the segment of the ion-exchange membrane to produce an output signal indicative of a magnitude of the force, wherein relative differences in the output signals conveyed from the flexible electrodes covering the different segments of the convex dome are further indicative of a direction of the force acting on the tactile sensor; and (c) an elastomeric support disposed within a concave cavity formed under the convex dome, the elastomeric support preventing a force applied against one or more of the plurality of flexible electrodes from inverting the ion-exchange membrane. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12)
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13. A method for producing a tactile sensor that enables a direction in which a force is applied to the tactile sensor to be determined, comprising the steps of:
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(a) applying flexible electrodes on opposite first and second surfaces of an ion-exchange membrane and configuring each flexible electrode defined on the first surface of the ion-exchange membrane to cover each of a plurality of different regions, forming an electroactive polymer; (b) molding the electroactive polymer to form a convex dome in which the plurality of different regions covered by the plurality of flexible electrodes comprise different circumferential segments arranged radially around the convex dome; (c) connecting electrical conductors to the plurality of the flexible electrodes on the first surface of the ion-exchange membrane and to a flexible electrode on the second surface of the ion-exchange membrane, the electrical conductors being operative to convey output signals from the different circumferential segments in response to a deformation of a circumferential segment by a force applied against the convex dome; and (d) providing a generally dome-shaped elastomeric support underlying the convex dome and the flexible electrode covering the second surface of the ion-exchange membrane, the elastomeric support preventing the ion-exchange membrane from inverting when a force is applied to the convex dome. - View Dependent Claims (14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24)
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25. A method for sensing a direction in which a force is applied to a tactile sensor, comprising the steps of:
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(a) providing a generally dome-shaped tactile sensor having a plurality of sensing regions disposed around the surface of the dome-shaped tactile sensor, each sensing region producing an output signal indicative of a deformation of the sensing region caused by a vector component of an applied force; (b) automatically processing the output signals to determine the direction in which the force was applied to the dome-shaped tactile sensor; and (c) providing an elastomeric material disposed under the dome-shaped tactile sensor for preventing the generally dome-shaped tactile sensor from inverting when it is deformed by an applied force. - View Dependent Claims (26, 27, 28)
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29. A tactile sensor array that is able to determine a direction in which a force is applied to stimulate the tactile sensor, comprising:
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(a) an electroactive polymer comprising a plurality of generally hemispherical shaped elements, each hemispherical element being divided into a plurality of different sensing regions that each produce a separate output signal when deformed by a force acting on the sensing region; (b) electrical conductors coupled to each of the sensing regions of the hemispherical shaped elements, for conveying the output signal produced by each to a processor that can determine a direction of the force applied to the tactile sensor array as a function of one or more vector components of the force applied to one or more of the regions comprising the hemispherical-shaped elements; and (c) an elastomeric substrate supporting the plurality of generally hemispherically-shaped elements, preventing them from being inverted by an applied force. - View Dependent Claims (30)
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31. A biocompatible tactile sensor that is able to remain continuously in contact with biological tissue without adversely affecting the biological tissue, comprising:
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(a) a sheet of an electroactive polymer formed to include a protuberance that extends outwardly from a surface of the sheet, the electroactive polymer including a plurality of electrodes covering different sensing regions around the protuberance, each sensing region producing an output signal indicating a magnitude of a force acting to displace the sensing region by deforming the protuberance; (b) electrical conductors that are coupled to the electrodes of the sensing regions and which convey the output signals from each sensing region; (c) a protective coating applied to the sheet of electroactive polymer, the protective coating being biocompatible to enable the electroactive polymer to contact biological tissue without adversely affecting the biological tissue; and (d) an elastomeric flexible support for the protuberance that prevents the protuberance from being inverted by a force that is applied to one or more sensing regions. - View Dependent Claims (32, 33)
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Specification