Stannous oxide force transducer and composition

• US 5,296,837 A
• Filed: 07/10/1992
• Issued: 03/22/1994
• Est. Priority Date: 07/10/1992
• Status: Expired due to Term

• Current Assignee: Interlink Electronics Incorporated
• Original Assignee: Interlink Electronics Incorporated
• Inventors: Yaniger, Stuart I.
• Primary Examiner(s): Lateef, Marvin M.
• Application Number:
  US07/911,769
• Time in Patent Office: 620 Days
• Field of Search: 338/99, 338/114, 338/47, 338/100, 338/111, 338/112, 338/115, 338/120, 338/122, 338/125, 252/502, 252/503, 252/506, 252/510, 252/511, 252/518
• US Class Current: 338/47
• CPC Class Codes: G01L 1/20 by measuring variations in ohmic resistance of solid materials or of electrically-conductive fluids of piezo-resistive materials G01L1/18; by making use of electrokinetic cells, i.e. liquid-containing cells wherein an electrical potential is produced or varied upon the application of stress
• CPC Class Codes: H01C 10/106 on resistive material dispersed in an elastic material H01C10/103 and H01C10/12 take precedence; for electric switches H01H1/029

Abstract

A pressure transducer includes a base ply, a resistance ply disposed on the base ply and at least two spaced apart conductors juxtaposed in relation to the resistance ply whereby at least one of the conductors may be pressed against the resistance ply. The resistance ply is made by spraying or silk screening a mixture of a continuous matrix conductive resin and a stannous oxide particulate and then curing the composition to form a solid resistance ply having a surface with a multiplicity of micro-protrusions formed by the stannous oxide particulate.

Claims

1. A transducer having a resistance which varies in response to the amount of applied force comprising:

a base ply;

a resistance ply disposed on the base ply, the resistance ply comprising;

a continuous matrix conductive resin; and

a stannous oxide particulate interspersed in the continuous matrix of conductive resin to form a surface with a plurality of microprotrusions formed by the stannous oxide particulate;

at least two spaced apart conductors electrically interconnected across the resistance ply to enable electrical conduction through the resistance ply, at least one of the conductors juxtaposed opposite the surface of the resistance ply for being pressed thereagainst, the resistance to electrical current conducting through the resistance ply varying in response to the amount of force applied to press the at least one conductor against the surface of the resistance ply.

2. The transducer of claim 1 wherein there are two conductors, both conductors being juxtaposed opposite the surface of the resistance ply, the resistance ply being electrically interconnected in shunt orientation across the two conductors.

3. The transducer of claim 1 wherein there are two conductors, one positioned on each side of the resistance ply whereby electrical current is conducted through the resistance ply.

4. The transducer of claim 1 wherein the conductive resin further comprises a non-conductive resin base and molecular sized carbon particulate mixed therein.

5. The transducer of claim 1 wherein the stannous oxide particulate has a particle size in the range of about 0.5 to 10 microns.

6. The transducer of claim 1 wherein the weight ratio of stannous oxide in the conductive resin is in the range of 4 parts stannous oxide particulate to 1 part conductive resin to about 1 part stannous oxide to 5 parts conductive resin.

7. The transducer of claim 1 wherein the resistance ply has a thickness of about 0.0002 to 0.001 inches.

8. The transducer of claim 4 wherein weight ratio of carbon to non-conductive resin is in the range of one part carbon to one hundred parts non-conductive resin base to one part carbon to four parts non-conductive resin base.

9. A composition of matter for being disposed in a thin layer for forming a resistance ply juxtaposed between at least two conductors, the thin layer defining a surface against which at least one of the conductors may be pressed, the resistance ply having a resistance which varies in response to the amount of force with which the at least one conductor is pressed against the surface of the resistance ply, the composition of matter comprising:

a conductive resin; and

stannous oxide particulate interspersed through the conductive resin.

10. The composition of matter of claim 9 wherein the conductive resin further comprises a non-conductive resin base and molecular sized carbon particles interspersed therein.

11. The composition of matter of claim 9 wherein the stannous oxide particulate has a particulate size in the range of about 0.5 to 10 microns.

12. The composition of matter of claim 10 wherein the stannous oxide particulate has a particulate size in the range of about 0.5 to 10 microns.

13. The composition of matter of claim 9 wherein the weight ratio of stannous oxide in the conductive resin is in the range of 4 parts stannous oxide particulate to 1 part conductive resin to about 1 part stannous oxide to 5 parts conductive resin.

14. The composition of matter of claim 10 wherein the weight ratio of stannous oxide in the conductive resin is in the range of 4 parts stannous oxide particulate to 1 part conductive resin to about 1 part stannous oxide to 5 parts conductive resin.

15. The composition of matter of claim 11 wherein the weight ratio of stannous oxide in the conductive resin is in the range of 4 parts stannous oxide particulate to 1 part conductive resin to about 1 part stannous oxide to 5 parts conductive resin.

16. The composition of matter of claim 12 wherein the weight ratio of stannous oxide in the conductive resin is in the range of 4 parts stannous oxide particulate to 1 part conductive resin to about 1 part stannous oxide to 5 parts conductive resin.

17. The composition of matter of claim 10 wherein the weight ratio of carbon to non-conductive resin is in the range of one part carbon to one hundred parts non-conductive resin base to one part carbon to four parts non-conductive resin base.

18. The composition of matter of claim 10 wherein weight ratio of carbon to non-conductive resin is in the range of one part carbon to one hundred parts non-conductive resin base to one part carbon to four parts non-conductive resin base.

19. The composition of matter of claim 11 wherein the conductive resin further comprises a non-conductive resin base and carbon particles interspersed therein, the weight ratio of carbon to non-conductive resin is in the range of one part carbon to one hundred parts non-conductive resin base to one part carbon to four parts non-conductive resin base.

20. The composition of matter of claim 12 wherein weight ratio of carbon to non-conductive resin is in the range of one part carbon to one hundred parts non-conductive resin base to one part carbon to four parts non-conductive resin base.

21. The composition of matter of claim 13 wherein the conductive resin further comprises a non-conductive resin base and carbon particles interspersed therein, the weight ratio of carbon to non-conductive resin is in the range of one part carbon to one hundred parts non-conductive resin base to one part carbon to four parts non-conductive resin base.

22. The composition of matter of claim 16 wherein weight ratio of carbon to non-conductive resin is in the range of one part carbon to one hundred parts non-conductive resin base to one part carbon to four parts non-conductive resin base.

23. A transducer having a resistance which varies in response to the amount of applied force comprising:

a first base ply;

a first conductor disposed on the first base ply;

a second base ply in facing relationship to the first base ply;

a second conductor disposed on the second base ply;

a first resistance ply disposed on the first conductor and a second resistance ply disposed on the second conductor and the first and second resistance plies comprising;

a continuous matrix conductive resin; and

a stannous oxide particulate interspersed in the continuous matrix of conductive resin to form a surface with a plurality of microprotrusions formed by the stannous oxide particulate;

the two conductors to enable electrical conduction through the first and second resistance plies, the first and second resistance plies juxtaposed opposite each other for being pressed together, the resistance to electrical current conducting through the first and second plies varying in response to the amount of force applied to press the surfaces of the first and second resistance plies together.