Tactile sensor element and sensor array

• US 20060016275A1
• Filed: 12/10/2003
• Published: 01/26/2006
• Est. Priority Date: 12/12/2002
• Status: Active Grant

• Current Assignee: Leap Technology Aps
• Original Assignee: Danfoss A/S
• Inventors: Gravesen, Peter, Benslimand, Mohamed Yahia
• Granted Patent: US 7,481,120 B2
• Time in Patent Office: Days
• US Class Current: 73/862.42
• CPC Class Codes: G06F 3/03547 Touch pads, in which fingers can move on a surface
• CPC Class Codes: G06F 3/0447 Position sensing using the local deformation of sensor cells

Abstract

A tactile sensor element includes a first pressure transfer layer and a second pressure transfer layer, an elastomeric body arranged between the first and second pressure transfer layers, the body having a first and a second surface opposed to each other, the first and second surfaces having corrugations to allow displacement of elastomeric body material in a predetermined direction perpendicular to the corrugations when exposed to a contact pressure on at least one of the surfaces, a first electrode arranged on the first surface and a second electrode arranged on the second surface, the first and the second electrodes being connectable to external means for determining the capacitance of a capacitor formed by the elastomeric body and the electrodes, where at least one pressure transfer layer has at least one portion of increased thickness. Further disclosed is a tactile sensor array comprising a plurality of sensor elements.

Claims

1. A tactile sensor element comprising:

a first pressure transfer layer and a second pressure transfer layer;

an elastomeric body arranged between the first and second pressure transfer layers, the body having a first surface and a second surface opposed to each other, the first and second surfaces having corrugations to allow displacement of elastomeric body material in a predetermined direction perpendicular to the corrugations when exposed to a contact pressure on at least one of the surfaces; and

a first electrode arranged on the first surface and a second electrode arranged on the second surface;

the first and the second electrodes being connectable to external means for determining the capacitance of a capacitor formed by the elastomeric body and the electrodes, wherein at least one pressure transfer layer has at least one portion of increased thickness.

2. The tactile sensor element according to claim 1, wherein at least one pressure transfer layer has a central portion of increased thickness and, on each side of the central portion in the predetermined direction of extension of the body, an end portion of decreased thickness.

3. The tactile sensor element according to claim 1, wherein the electrode on at least one of the surfaces comprise a first electrode portion adjacent to the central portion of the pressure transfer layer and second electrode portions adjacent to the end portions of the pressure transfer layer, the first and second electrode portions being isolated from each other.

4. The tactile sensor element according claim 3, wherein the surface area of the first electrode portion is substantially equal to the total surface area of the second electrode portions.

5. The tactile-sensor element according to claim 1, wherein lateral means are provided on two opposite sides of the sensor element for preventing overall dimensional change of the sensor element in the predetermined direction.

6. The tactile sensor element according to claim 1, wherein the thickness of the pressure transfer layer is substantially equal to the thickness of the elastomeric body.

7. The tactile sensor element according to claim 1, wherein the elastomeric body and the pressure transfer layers have similar elastomeric properties.

8. The tactile sensor array comprising a plurality of sensor elements according to claim 1, wherein the sensor elements are arranged in a row and column configuration for the determination of local pressure variations over the surface area of the sensor array, and wherein the plurality of sensor elements being integrally formed in a common elastomeric body member.

9. The tactile sensor array according to claim 8, wherein each row of sensor elements comprises an elongated common elastomeric body member, the body member constituting a continuous sequence of sensor element bodies.

10. The tactile sensor array according to claim 9, wherein the elastomeric body member has corrugations extending perpendicular to the longitudinal direction of the elongated body member, and wherein adjacent body members are spaced from each other.

11. A tactile sensor array comprising:

a plurality of sensor elements arranged in a row and column configuration for the determination of local pressure variations over the surface area of the sensor array, and wherein the plurality of sensor elements being integrally formed in a common elastomeric body member;

wherein each of the sensor elements comprises a first pressure transfer layer and a second pressure transfer layer;

an elastomeric body arranged between the first and second pressure transfer layers, the body having a first surface and a second surface opposed to each other, the first and second surfaces having corrugations to allow displacement of elastomeric body material in a predetermined direction perpendicular to the corrugations when exposed to a contact pressure on at least one of the surfaces; and

a first electrode arranged on the first surface and a second electrode arranged on the second surface;

the first and the second electrodes being connectable to external means for determining the capacitance of a capacitor formed by the elastomeric body and the electrodes, wherein at least one pressure transfer layer has at least one portion of increased thickness.

12. The tactile sensor array according to claim 11, wherein each row of sensor elements comprises an elongated common elastomeric body member, the body member constituting a continuous sequence of sensor element bodies.

13. The tactile sensor array according to claim 12, wherein the elastomeric body member has corrugations extending perpendicular to the longitudinal direction of the elongated body member, and wherein adjacent body members are spaced from each other.