Internally shock caged serpentine flexure for micro-machined accelerometer
First Claim
1. A micro-machined electromechanical sensor (MEMS) device, comprising a serpentine flexure comprising:
- a plurality of spaced-apart elongated flexure members formed through the thickness of a substrate as substantially planar elements and being relatively narrow as measured crosswise to their longitudinal axes;
a plurality of relatively short interconnecting members arranged crosswise to the longitudinal axes of the elongated flexure members and interconnecting opposite ends of alternate pairs of the elongated flexure members in a serpentine configuration, including first and last relatively short interconnecting members arranged crosswise to the longitudinal axes of respective first and last ones of the elongated flexure members and being structured for interconnecting the respective first and last elongated flexure members between relatively movable and immovable device components; and
means for internally-caging one or more of the spaced-apart elongated flexure members, the means for internally-caging comprising an extension formed on one end of one or more of the interconnecting members and extending a part of the distance between one of the members interconnecting one pair of the spaced-apart elongated flexure members and an end of a next adjacent member interconnecting a next adjacent pair of the spaced-apart elongated flexure members.
1 Assignment
0 Petitions
Accused Products
Abstract
An apparatus and method for sensing accelerations and other forces. The apparatus having a capacitance pick-off force sensor having a proof mass that is suspended relative to a relatively stationary frame by a plurality of serpentine suspension members having internal caging. The device provides easily implemented fabrication modification for trading-off between input range and pick-off sensitivity by altering etching periods of the serpentine suspension members. The input range and pick-off sensitivity can be traded-off by enlarging or reducing the quantity of elongated flexure fingers forming the serpentine suspension member. Different ones of the elongated flexure fingers are optionally formed with different thicknesses, whereby the serpentine suspension member exhibits a spring rate that progressively increases as it is compressed by in-plane motion of the proof mass relative to the relatively stationary frame.
74 Citations
13 Claims
-
1. A micro-machined electromechanical sensor (MEMS) device, comprising a serpentine flexure comprising:
-
a plurality of spaced-apart elongated flexure members formed through the thickness of a substrate as substantially planar elements and being relatively narrow as measured crosswise to their longitudinal axes; a plurality of relatively short interconnecting members arranged crosswise to the longitudinal axes of the elongated flexure members and interconnecting opposite ends of alternate pairs of the elongated flexure members in a serpentine configuration, including first and last relatively short interconnecting members arranged crosswise to the longitudinal axes of respective first and last ones of the elongated flexure members and being structured for interconnecting the respective first and last elongated flexure members between relatively movable and immovable device components; and means for internally-caging one or more of the spaced-apart elongated flexure members, the means for internally-caging comprising an extension formed on one end of one or more of the interconnecting members and extending a part of the distance between one of the members interconnecting one pair of the spaced-apart elongated flexure members and an end of a next adjacent member interconnecting a next adjacent pair of the spaced-apart elongated flexure members. - View Dependent Claims (2, 3, 11, 12, 13)
-
-
4. A micro-machined electromechanical sensor (MEMS) device having a serpentine flexure, the serpentine flexure comprising:
-
a plurality of elongated flexure members each formed through the thickness of a substrate as substantially planar elements; a relatively short interconnecting member arranged crosswise to the longitudinal axes of the elongated flexure members and interconnecting opposite ends of alternate pairs of the elongated flexure members in a serpentine configuration, one or more of the plurality of elongated flexure members being thicker than one or more others of the elongated flexure members; and a small mass extending a part of a distance between adjacent elongated flexure members. - View Dependent Claims (5, 6)
-
-
7. A micro-machined electromechanical sensor (MEMS) device having a serpentine flexure, the serpentine flexure comprising:
-
a plurality of elongated flexure members each formed through the thickness of a substrate as substantially planar elements; a relatively short interconnecting member arranged crosswise to the longitudinal axes of the elongated flexure members and interconnecting opposite ends of alternate pairs of the elongated flexure members in a serpentine configuration; and a small mass comprising an extension formed on one end of the interconnecting member and extending a part of a distance between adjacent elongated flexure members. - View Dependent Claims (8, 9, 10)
-
Specification