MEMS multi-directional shock sensor

• US 7,159,442 B1
• Filed: 01/06/2005
• Issued: 01/09/2007
• Est. Priority Date: 01/06/2005
• Status: Expired due to Fees

• Current Assignee: the united states of america as represented by the secretary of the navy
• Original Assignee: the united states of america as represented by the secretary of the navy
• Inventors: Jean, Daniel J.
• Primary Examiner(s): Lefkowitz; Edward
• Assistant Examiner(s): Kirkland, III; Freddie
• Application Number:
  US11/040,300
• Time in Patent Office: 733 Days
• Field of Search: 73/120.1, 734/88, 735/140.1, 735/140.2, 735/141.5, 735/141.6, 735/142.9, 735/143.5, 735/143.6, 735/143.8
• US Class Current: 73/12.01
• CPC Class Codes: G01P 1/023 for acceleration measuring devices
• CPC Class Codes: G01P 15/08 with conversion into electric or magnetic values
• CPC Class Codes: G01P 15/0891 with indication of predetermined acceleration values G01P15/135 takes precedence
• CPC Class Codes: G01P 15/135 by making use of contacts which are actuated by a movable inertial mass
• CPC Class Codes: G01P 15/18 in two or more dimensions
• CPC Class Codes: H01H 2001/0068 with multi dimensional movement, i.e. the movable actuator performing movements in at least two different directions
• CPC Class Codes: H01H 2001/0078 with parallel movement of the movable contact relative to the substrate
• CPC Class Codes: H01H 35/14 Switches operated by change of acceleration, e.g. by shock or vibration, inertia switch wherein the liquid constitutes a contact of the switch H01H29/002

Abstract

A multi-directional shock sensor having a central post surrounded by an omnidirectionally moveable toroidal mass. A plurality of anchor members surrounds the mass and carries one arm of a latching arm assembly. The other arm of each latching arm assembly is carried by, and radially extends from the mass to oppose a respective first arm. A shock event will cause the mass to move in a certain direction to an extent where one or more of the arm assemblies will latch. The latching may be determined by an electrical circuit connected to contact pads on the central post and on the anchor members.

Claims

1. A multi-directional shock sensor, comprising:

a central post;

a toroidal mass surrounding said central post;

a spring arrangement connecting said toroidal mass with said central post allowing for omnidirectional movement of said toroidal mass;

a plurality of anchor members surrounding said toroidal mass; and

a plurality of latching arm assemblies where each latching arm assembly includes a first arm being opposed to a second arm,

wherein each said first arm is connected to a respective anchor member of said plurality of anchor members,

wherein each said second arm is connected to said toroidal mass, and

wherein movement of said toroidal mass due to a shock event causes at least one of said second arm to engage and latch with an opposed one of said first arm, whereby the shock event and direction of said shock event is determined.

2. The multi-directional shock sensor according to claim 1, wherein each said respective anchor member includes a notch portion, said first arm is positioned in said notch portion.

3. The multi-directional shock sensor according to claim 2, wherein said notch portion is situated along an edge of said respective anchor member.

4. The multi-directional shock sensor according to claim 2, wherein said notch portion is substantially a reversed “

L”

shaped notch portion.

5. A multi-directional shock sensor coordinate system for shock readings, comprising:

a support structure, comprising;

a plurality of contact surfaces and a shock surface; and

a plurality of multi-directional shock sensor packages according to claim 2 being affixed to said plurality of contact surfaces,

wherein said notch portion is substantially a reversed “

L”

shaped notch portion,

wherein said plurality of contact surfaces comprise at least three mutually perpendicular surfaces, and

wherein said shock surface is perpendicular to said plurality of contact surfaces where said shock surface is subjected to a shock event.

6. The multi-directional shock sensor according to claim 1, wherein said toroidal mass includes a plurality of radial notches where each said first arm occupies and extends from a respective radial notch of said plurality of radial notches in said toroidal mass.

7. The multi-directional shock sensor according to claim 1, wherein said multi-directional sensor is comprised of electrically conductive material.

8. The multi-directional shock sensor according to claim 7, wherein said electrically conductive material is silicon doped to make it electrically conducting.

9. The multi-directional shock sensor according to claim 1, further comprising a plurality of electric contact pads comprising one pad being positioned on said central post, and each remaining pad of said plurality of electric contact pads being positioned on said respective anchor member.

10. The multi-directional shock sensor according to claim 9, further comprising electric circuitry connecting to said plurality of electric contact pads for determining a status of whether at least one of said plurality of latching arm assemblies has latched after a shock event.

11. The multi-directional shock sensor according to claim 1, wherein said toroidal mass is initially formed on, and attached to, an insulating layer, and

wherein said toroidal mass includes a plurality of apertures extending from a top surface of said toroidal mass down to said insulating layer and allow an etchant to pass through said plurality of apertures and dissolve said insulating layer beneath said toroidal mass.

12. The multi-directional shock sensor according to claim 1, wherein said first arm and said second arm each comprise a latching segment.

13. The multi-directional shock sensor according to claim 12, wherein said latching segment comprises an arrowhead shaped latching segment.

14. A multi-directional shock sensor package, comprising:

a hermetically sealed package; and

a multi-directional shock sensor according to claim 1,

wherein said multi-directional sensor is positioned within said hermetically sealed package, and

wherein said hermetically sealed package comprises leads electrically connected to a plurality of electric contact pads of said multi-directional sensor.

15. A multi-directional shock sensor package, comprising:

a circuit board;

a multi-directional shock sensor according to claim 1 being surrounded by a border and being situated on said circuit board; and

a lid being sealed to said border.

16. The multi-directional shock sensor according to claim 1, wherein said shock event is in a range of about 5 gs to about 30,000 gs.

17. The multi-directional shock sensor according to claim 1, wherein said shock event is in a range of about 50 gs to about 3,000 gs.

18. The multi-directional shock sensor according to claim 1, wherein said toroidal mass is a moveable toroidal mass for movement opposite to said shock event in a plane of said multi-directional shock sensor.

19. The multi-directional shock sensor according to claim 1, further comprising an insulating layer under said first arm arm and said second arm,

wherein said first arm and said second arm are moveable independent of said insulating layer.