US4980646A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Impedance tomographic tactile sensor
Assignee: TRUSTEES OF UNIVERSITY OF PENNSYLVANIA A CORP OF
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Filing: 1988-03-30
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Granted: 1990-12-25
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Expires: 2008-03-30
Abstract
Abstract Disclosed is a container holding a partially conductive ionic fluid with a flexible tactile surface covering the fluid and sealing the container. Along the bottom of the container a series of parallel conductors are located with the farthest spaced apart conductors being connected to a voltage source. Measurements of changes in voltages between individual pairs of conductors will provide an indication of any localized deformation of the flexible tactile surface. Such a tactile sensor can be utilized in any device where an electrical output is desired which is indicative of the surface or surface characteristics of the object to be contacted.
Inventors
- 👤 Jay N. Zemel
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 18:34
CPC Classifications
G; G01; G01D; G01D5/00; G01D5/12; G01D5/25; G01D5/252
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
96 words
An impedance tactile sensor for providing an electrical indication of contact with the sensor, said tactile sensor comprising: a volume of an at least partially conducting fluid; means for containing said partially conducting fluid, said means including a flexible tactile surface; means for applying a voltage across a measurement length of said fluid causing local voltage drops in said fluid; and means for measuring any changes in local voltage drop, said changes defined as the difference between any local voltage drop without contact with said surface and any local voltage drop during contact with said surface.
Claim 2
Dependent Claim
96 words
An impedance tactile sensor for providing an electrical indication of contact with the sensor, said tactile sensor comprising: a volume of an at least partially conducting fluid; means for containing said partially conducting fluid, said means including a flexible tactile surface; means for applying a voltage across a measurement length of said fluid causing local voltage drops in said fluid; and means for measuring any changes in local voltage drop, said changes defined as the difference between any local voltage drop without contact with said surface and any local voltage drop during contact with said surface.
Claim 3
Dependent Claim
172 words
An impedance tactile sensor for providing an electrical indication of contact with the sensor, said tactile sensor comprising: a volume of an at least partially conducting fluid; means for containing said fluid, said means having a flexible tactile surface to be contacted, said fluid having a constant volume; means for supporting an array of at least three conductors spaced apart in a direction substantially parallel to said tactile surface, two of said at least three conductors being spaced furthest apart; means for applying a voltage across said two spaced furthest apart conductors, and means for measuring any change in voltage drop across local pairs of conductors, with and without contact with said sensor, said change being the result of indentation of said tactile surface, where the magnitude of a change associated with each local pair of conductors is indicative of an average change in local fluid thickness associated with each local pair of conductors and therefore a change in the position of said flexible tactile surface at said local pair of conductors.
Claim 4
Dependent Claim
172 words
An impedance tactile sensor for providing an electrical indication of contact with the sensor, said tactile sensor comprising: a volume of an at least partially conducting fluid; means for containing said fluid, said means having a flexible tactile surface to be contacted, said fluid having a constant volume; means for supporting an array of at least three conductors spaced apart in a direction substantially parallel to said tactile surface, two of said at least three conductors being spaced furthest apart; means for applying a voltage across said two spaced furthest apart conductors, and means for measuring any change in voltage drop across local pairs of conductors, with and without contact with said sensor, said change being the result of indentation of said tactile surface, where the magnitude of a change associated with each local pair of conductors is indicative of an average change in local fluid thickness associated with each local pair of conductors and therefore a change in the position of said flexible tactile surface at said local pair of conductors.
Claim 5
Dependent Claim
45 words
An impedance tactile sensor according to claim 2, wherein said means for containing comprises: a two-dimensional surface; a boundary means on said two-dimensional surface defining the periphery of said two-dimensional surface; and an elastic film means, attached to said boundary means, comprising said tactile surface.
Claim 6
Dependent Claim
21 words
An impedance tactile sensor in accordance with claim 3, wherein said boundary means comprises a rectangular boundary on said two-dimensional surface.
Claim 7
Dependent Claim
26 words
An impedance tactile sensor in accordance with claim 4, wherein said two-dimensional surface and said boundary means are comprised of densified Al 2 O 3 .
Claim 8
Dependent Claim
22 words
An impedance tactile sensor in accordance with claim 2, wherein said conductors are parallel to each other and are adjacent one another.
Claim 9
Dependent Claim
19 words
An impedance tactile sensor in accordance with claim 6, wherein said conductors comprise photolithographically defined strips of conductive material.
Claim 10
Dependent Claim
15 words
An impedance tactile sensor in accordance with claim 7, wherein said conductive material is gold.
Claim 11
Dependent Claim
24 words
An impedance tactile sensor in accordance with claim 2, wherein said measuring means measures the change in voltage drop across adjacent pairs of conductors.
Claim 12
Dependent Claim
19 words
An impedance tactile sensor in accordance with claim 2, wherein said at least partially conducting fluid comprises ethylene glycol.
Claim 13
Dependent Claim
145 words
An impedance tactile sensor for providing an electrical indication of contact with the sensor, said tactile sensor comprising: a volume of ethylene glycol; a means for containing said ethylene glycol comprising a substrate and rectangular boundary of densified Al 2 O 3 with a flexible tactile surface said substrate, rectangular boundary and said tactile surface comprising a constant volume; a plurality of conductors photolithographically defined on said two-dimensional surface having two conductors which are spaced furthest apart; means for applying a voltage across said two spaced furthest apart conductors; and means for measuring any change in voltage drop across adjacent pairs of conductors with and without contact of said flexible tactile surface, where the magnitude of any voltage change across a local pair of conductors is indicative of the average change in local fluid thickness and therefore change in position of said flexible tactile surface.
Claim 14
Dependent Claim
145 words
An impedance tactile sensor for providing an electrical indication of contact with the sensor, said tactile sensor comprising: a volume of ethylene glycol; a means for containing said ethylene glycol comprising a substrate and rectangular boundary of densified Al 2 O 3 with a flexible tactile surface said substrate, rectangular boundary and said tactile surface comprising a constant volume; a plurality of conductors photolithographically defined on said two-dimensional surface having two conductors which are spaced furthest apart; means for applying a voltage across said two spaced furthest apart conductors; and means for measuring any change in voltage drop across adjacent pairs of conductors with and without contact of said flexible tactile surface, where the magnitude of any voltage change across a local pair of conductors is indicative of the average change in local fluid thickness and therefore change in position of said flexible tactile surface.
Claim 15
Independent Claim
224 words
A method of locating and characterizing contact with a flexible surface, including the steps of: providing a means for containing an at least partially conductive fluid with the containing means having at least a flexible tactile surface; means for applying a voltage across a measurement length of said fluid causing local voltage drops; means for measuring any changes in local voltage drops where said change is defined as the difference between any local voltage drop without contact with said tactile surface and any local voltage drop during contact with said tactile surface; measuring voltage drops with and without contact of said flexible tactile surface, for each pair of conductors; computing the local change in height of said tactile surface above a substrate for each pair of conductors in accordance with: ##EQU7## where n is the local pair of conductors being measured, ΔV n is the change in local voltage drop associated with the nth pair of conductors, d is the spacing between the adjacent nth pair of conductors in a measurement direction, L is the distance between the spaced furthest apart conductors in said measurement direction, H is the local height of fluid above said substrate, δH is the local change in height of the fluid at the nth pair of conductors, and V is the voltage applied to the spaced furthest apart conductors.
Claim 16
Independent Claim
224 words
A method of locating and characterizing contact with a flexible surface, including the steps of: providing a means for containing an at least partially conductive fluid with the containing means having at least a flexible tactile surface; means for applying a voltage across a measurement length of said fluid causing local voltage drops; means for measuring any changes in local voltage drops where said change is defined as the difference between any local voltage drop without contact with said tactile surface and any local voltage drop during contact with said tactile surface; measuring voltage drops with and without contact of said flexible tactile surface, for each pair of conductors; computing the local change in height of said tactile surface above a substrate for each pair of conductors in accordance with: ##EQU7## where n is the local pair of conductors being measured, ΔV n is the change in local voltage drop associated with the nth pair of conductors, d is the spacing between the adjacent nth pair of conductors in a measurement direction, L is the distance between the spaced furthest apart conductors in said measurement direction, H is the local height of fluid above said substrate, δH is the local change in height of the fluid at the nth pair of conductors, and V is the voltage applied to the spaced furthest apart conductors.
Claim 17
Independent Claim
113 words
A method of locating and characterizing contact with a flexible surface, including the steps of: providing a means for containing an at least partially conductive fluid with said containing means having at least a flexible tactile surface; applying a voltage across a measurement length of said fluid causing local voltage drops; measuring any changes in local voltage drops where said change is defined as the difference between any local voltage drop without contact with said tactile surface and any local voltage drop during contact with said tactile surface, said any difference between said measured voltage drops without contact of said flexible tactile surface comprising an output indicative of contact with said tactile surface.
Claim 18
Independent Claim
113 words
A method of locating and characterizing contact with a flexible surface, including the steps of: providing a means for containing an at least partially conductive fluid with said containing means having at least a flexible tactile surface; applying a voltage across a measurement length of said fluid causing local voltage drops; measuring any changes in local voltage drops where said change is defined as the difference between any local voltage drop without contact with said tactile surface and any local voltage drop during contact with said tactile surface, said any difference between said measured voltage drops without contact of said flexible tactile surface comprising an output indicative of contact with said tactile surface.
Claim 19
Dependent Claim
109 words
A method according to claim 13, wherein said providing step includes supporting an array of at least three conductors spaced apart in a direction substantially parallel to the tactile surface, two of said at least three conductors being spaced farthest apart, said applying step comprising applying a voltage across said two spaced farthest apart conductors, said measuring step comprising measuring voltage drops across local pairs of conductors wherein the magnitude of any change in voltage associated with the local pair of conductors is indicative of an average change in local fluid thickness and therefore indicative of a deflection of the flexible tactile surface at said local pair of conductors.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-12-24 | 1994-06-25 | 1994-12-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-12-24 | 1998-06-25 | 1998-12-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-12-24 | 2002-06-25 | 2002-12-25 | $7700.00 | Window Closed / Lapsed |