Measuring pressure exerted by a rigid surface

• US 20040112138A1
• Filed: 12/16/2002
• Published: 06/17/2004
• Est. Priority Date: 12/16/2002
• Status: Active Grant

• Current Assignee: Jeffrey G. Knirck, Paul A. Swanson
• Original Assignee: Jeffrey G. Knirck, Paul A. Swanson
• Inventors: Swanson, Paul A., Knirck, Jeffrey G.
• Granted Patent: US 6,931,938 B2
• Time in Patent Office: Days
• US Class Current: 73/754
• CPC Class Codes: G01L 1/205 using distributed sensing elements
• CPC Class Codes: G01L 9/0002 using variations in ohmic resistance G01L9/0051 takes precedence

Abstract

A means to accurately measure the pressure distribution across a rigid or semi-rigid surface, or between two rigid or semi-rigid surfaces with high special resolution is disclosed. The present invention relates to measuring a pressure distribution. The present invention would be ideal for use in various types of manufacturing tooling and various in situ industrial machine controls. The present invention uses an array of commercial micro-machined silicon pressure sensing die attached to a substrate and encapsulated in an elastomer.

Claims

1. A pressure sensor apparatus, comprising:

a substrate;

a pressure sensor secured to the substrate; and

a planar elastomeric layer covering the pressure sensor to spread an applied force over an area at least as large as the pressure sensor.

2. A pressure sensor apparatus of claim 1, wherein the substrate is an elastomer.

3. A pressure sensor apparatus of claim 1, wherein the substrate is rigid.

4. A pressure sensor apparatus of claim 1, further comprising:

multiple pressure sensors secured to the substrate; and

the elastomeric layer covering the pressure sensors forms a relatively constant thickness of elastomer on each pressure sensor.

5. A pressure sensor apparatus of claim 1, further comprising:

multiple pressure sensors secured to the substrate; and

a rigid barrier surrounding at least one of the pressure sensors.

6. A pressure sensor apparatus of claim 1, wherein the pressure sensor is constructed to form an electrical Wheatstone Bridge.

7. A pressure sensor apparatus of claim 1, wherein the substrate is a printed circuit board.

8. A pressure sensor apparatus of claim 1, wherein the pressure sensor is constructed as an individual micro-machined die.

9. A pressure sensor apparatus of claim 1, further comprising:

a means to compensate the temperature effects of the elastomeric layer covering the pressure sensor.

10. A pressure sensor apparatus of claim 1, further comprising:

a compliant low friction layer covering the elastomeric layer so that the body being measured does not stick to the elastomer.