System for sensing and displaying softness and force

• US 8,596,111 B2
• Filed: 04/20/2009
• Issued: 12/03/2013
• Est. Priority Date: 04/18/2008
• Status: Active Grant

• Current Assignee: Concordia University
• Original Assignee: Concordia University
• Inventors: Dargahi, Javad, Sokhanvar, Saeed
• Primary Examiner(s): Williams, Hezron E
• Assistant Examiner(s): MERCADO, ALEXANDER A
• Application Number:
  US12/988,410
• Publication Number:
  US 20110107842A1
• Time in Patent Office: 1,688 Days
• Field of Search: 737/80, 73/78, 737/67, 737/74, 737/88, 738/623.91, 738/624.51, 738/625.41
• US Class Current: 73/78
• CPC Class Codes: A61B 2090/064 for measuring force, pressure or mechanical tension
• CPC Class Codes: A61B 90/06 Measuring instruments not otherwise provided for
• CPC Class Codes: G01N 2203/0623 using piezoelectric gauges
• CPC Class Codes: G01N 3/40 Investigating hardness or rebound hardness

Abstract

A sensing element for sensing the softness of an object by abutting the sensing element against the object and biasing the sensing element toward the object with a biasing force. The sensing element includes a deformable section, the deformable section being deformable between an undeformed configuration and a deformed configuration, the deformed configuration being achievable when the deformable section is abutted against and biased toward the object; a deformation sensor operatively coupled to the deformable section for sensing a deformation of the deformable section between the deformed and undeformed configurations; and a force sensor operatively coupled to the deformable section for sensing the biasing force exerted onto the deformable section by the object when the deformable section is biased toward the object with the biasing force.

Claims

1. A sensing element for sensing the softness of an object by abutting said sensing element against said object and biasing said sensing element toward said object with a biasing force, said sensing element comprising:

a deformable section, said deformable section defining a deformable section contact surface, said deformable section contact surface being deformable between an undeformed configuration and a deformed configuration, said deformed configuration being achievable when said deformable section contact surface is abutted against and biased toward said object;

a deformation sensor operatively coupled to said deformable section for sensing a deformation of said deformable section contact surface between said deformed and undeformed configurations; and

a force sensor operatively coupled to said deformable section for sensing said biasing force exerted onto said deformable section contact surface by said object when said deformable section contact surface is biased toward said object with said biasing force;

wherein said biasing force and said deformation are sensed respectively by said force sensor and said deformation sensor independently from each other.

2. A sensing element as defined in claim 1, further comprising

a base;

and

a spacing element extending substantially away from said base;

said deformable section being supported by said spacing element in a substantially spaced apart relationship relatively to said base.

3. A sensing element as defined in claim 2, wherein said deformable section contact surface and said base are substantially parallel to each other.

4. A sensing element as defined in claim 2, wherein said deformation sensor includes a piezoelectric material operatively coupled to said deformable section for producing an electrical signal upon a deformation of said deformable section contact surface between said deformed and undeformed configurations.

5. A sensing element as defined in claim 2, wherein said deformation sensor includes a capacitor operatively coupled to said deformable section and to said base for producing an electrical signal upon a deformation of said deformable section contact surface between said deformed and undeformed configurations.

6. A sensing element as defined in claim 5, wherein said capacitor includes a first metal plate secured to said base and a second metal plate secured to said deformable section, said first and second metal plates being substantially in register with each other.

7. A sensing element as defined in claim 6, wherein said first and second metal plates are located between said deformable section and said base.

8. A sensing element as defined in claim 2, wherein said force sensor is mechanically coupled to said spacing element for sensing a force exerted on said spacing element when said deformable section contact surface is abutted against and biased toward said object.

9. A sensing element as defined in claim 8, wherein said force sensor includes a piezoelectric material operatively coupled to said spacing element for producing an electrical signal upon a force being exerted on said spacing element.

10. A sensing element as defined in claim 9, wherein said piezoelectric material is provided between said base and said spacing element.

11. A sensing element as defined in claim 1, further comprising

a base;

and

a pair of spacing elements extending substantially away from said base and supporting said deformable section in a substantially spaced apart relationship relatively to said base;

said deformable section contact surface extending between said spacing elements.

12. A sensing element as defined in claim 1, further comprising

a harder material, said harder material defining a recess extending thereinto;

said deformable section including a softer material substantially filling said recess, said softer material being substantially more deformable than said harder material when said deformable section and said harder material are simultaneously abutted against and biased toward said object.

13. A sensing element as defined in claim 12, wherein said force sensor includes a piezoelectric material mechanically coupled to said harder material and to said deformable section for sensing forces exerted onto said softer material and said harder material when said softer material and said harder material are simultaneously abutted against and biased toward said object.

14. A sensing element as defined in claim 12, wherein said harder material and said deformable section together define an abutment surface for abutting against said object, said sensing element comprising a sheet of piezoelectric material mechanically coupled to both said softer material and said harder material substantially opposed to said abutment surface.

15. A sensing element as defined in claim 14, wherein:

said deformation sensor includes a deformation sensor electrode electrically coupled to said sheet of piezoelectric material for receiving electrical signals from said sheet of piezoelectric material when a force is exerted onto said softer material; and

said force sensor includes a force sensor electrode electrically coupled to said sheet of piezoelectric material for receiving electrical signals from said sheet of piezoelectric material when a force is exerted onto said harder material;

said force sensor and deformation sensor electrodes are electrically insulated from each other.

16. A softness sensor, said softness sensor including a plurality of sensing elements as defined in claim 1, said plurality of sensing elements being distributed over a predetermined sensing surface.

17. A softness sensor as defined in claim 16, wherein said predetermined sensing surface is substantially planar.