Pressure sensing device

• US 4,763,534 A
• Filed: 01/31/1985
• Issued: 08/16/1988
• Est. Priority Date: 01/31/1985
• Status: Expired due to Fees

• Current Assignee: Robert G. Fulks
• Original Assignee: Robert G. Fulks
• Inventors: Hager, Robert J.
• Primary Examiner(s): Ruehl, Charles A.
• Application Number:
  US06/696,695
• Time in Patent Office: 1,293 Days
• Field of Search: 73/862.01, 73/862.68, 338/47, 338/99, 338/100, 338/114, 340/365 A
• US Class Current: 73/862.68
• 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

Abstract

A pressure sensing device utilizing force transducer ink comprises a resistive region deposited between a first and a second conducting region on a first insulating material, the resistive region electrically coupling the two conducting regions. On a second insulating material, a conducting region is deposited and a layer of force transducer ink is deposited over the conducting region. The two insulating materials are positioned in such a manner that the pressure transducer ink is in contact with the resistive region and separates the resistive and coupled conducting regions from the conducting region. A determination of the force applied to this configuration can be made by measuring the resistance between the first and second conducting regions. According to a second embodiment, a second resistive region and coupled conducting regions replace the conducting region on the second insulating material. By orienting the two resistive conducting element configuration, a position of a force applied to the pressure sensing device can be determined as well as the strength of the force.

Claims

1. A pressure sensing device comprising:

a first and a second electrode;

a resistive region electrically coupled to said first and said second electrode;

a conducting region;

a layer of force transducer ink separating said conducting region from said resistive region and;

means for measuring a change in an electrical parameter between said first and second electrodes to determine a value of force, when pressure is applied to said regions.

2. The pressure sensing device of claim 1 wherein said first and said second electrodes and said resistive region are deposited on a first insulating material;

and wherein said conducting region and said force transducing ink are deposited on a second insulating material.

3. The method of sensing pressure comprising the steps of:

depositing a resistive region on insulating material;

coupling conducting electrodes to said resistive region;

providing a conducting region overlying said resistive region;

separating said resistive region from said conducting region by a region of force transducer ink; and

measuring a change in resistive value between said conducting electrodes when pressure is applied to said regions.

4. The method of sensing pressure of claim 3 further comprising the step of calibrating said change in resistive value with a known force to provide a quantitive measure of applied pressure.

5. A pressure sensing device comprising:

a first insulating material;

a second insulating material;

a conducting layer in contact with an inner surface of said first insulating material;

a layer of force transducer ink in contact with said conducting layer;

a resistive element in contact with said force transducer ink layer and said second insulating material, said resistive element having a plurality of conducting regions coupled thereto; and

means for measuring a change in an electrical parameter between said plurality of conducting regions to provide a value of force when pressure is applied to said layers.

6. The method of measuring a force comprising the steps of:

measuring a resistive value of a layer of resistive material;

separating said resistive material from a conducting layer of material by a layer of force transducer ink; and

measuring a change in resistance of said layer of resistive material when a force is transmitted to said layer of force transducer ink.