Deformable segmented MEMS mirror
First Claim
1. A MEMS device, comprising a plurality of movable segments, each segment supported by springs and positioned offset from a substrate by an offset distance, wherein:
- each spring is attached between a corresponding stationary structure and a corresponding movable segment, said stationary structure fixed with respect to the substrate;
each movable segment is adapted to move with respect to the substrate to change the offset distance;
at least one movable segment has a hexagonal shape; and
exactly three springs are attached to the at least one movable segment such that each of the three said springs is attached to a different stationary structure.
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Accused Products
Abstract
A MEMS device having a deformable segmented mirror. The mirror includes a plurality of movable segments supported on a substrate using spring vertices, each vertex having a fixed plate and one or more springs. In a representative embodiment, three springs support each movable segment, where each spring connects the movable segment to a different spring vertex. The MEMS device also has a plurality of electrodes, each of which can be individually biased. A movable segment moves in response to a voltage applied to an electrode located beneath that segment while the deformed springs attached to the segment provide a restoring force. Due to the fixed plates, motion of each movable segment is substantially decoupled from that of the adjacent segments, which makes the shape of the segmented mirror relatively easy to control. In addition, segments in a deformable mirror of the invention can be displaced by a distance that is significantly larger than the maximum deformation amplitude for a membrane mirror of the prior art. The MEMS device can be fabricated using two silicon-on-insulator (SOI) wafers and an etch fabrication technique.
53 Citations
22 Claims
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1. A MEMS device, comprising a plurality of movable segments, each segment supported by springs and positioned offset from a substrate by an offset distance, wherein:
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each spring is attached between a corresponding stationary structure and a corresponding movable segment, said stationary structure fixed with respect to the substrate;
each movable segment is adapted to move with respect to the substrate to change the offset distance;
at least one movable segment has a hexagonal shape; and
exactly three springs are attached to the at least one movable segment such that each of the three said springs is attached to a different stationary structure. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. A method of fabricating a MEMS device, comprising:
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forming a plurality of movable segments, each segment supported by springs and positioned offset from a substrate by an offset distance, wherein;
each spring is attached between a corresponding stationary structure fixedly supported on the substrate and a corresponding movable segment; and
each movable segment is adapted to move with respect to the substrate to change the offset distance;
for each stationary structure, forming a post, wherein;
the stationary structure is rigidly attached to the post and the past is designed to support said stationary structure on the substrate;
the plurality of segments, the springs, and the posts are formed using a first wafer; and
a second wafer comprises the substrate;
forming an open grid structure adjacent to the plurality of segments and the springs using the first wafer;
transferring pressure via the open grid structure to the termini of the posts to bond the first and second wafers; and
removing the open grid structure from the first wafer. - View Dependent Claims (10, 11)
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12. A method of fabricating a MEMS device, comprising:
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forming a plurality of segments, a plurality of spring vertices, a plurality of posts, and a grid structure using a first wafer, wherein the grid structure is adjacent to the pluralities of segments and spring vertices;
bonding the first wafer together with a second wafer using the grid structure; and
removing the grid structure to release the pluralities of segments and spring vertices. - View Dependent Claims (13, 14)
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15. A MEMS device, comprising a plurality of movable segments, each segment supported by springs and positioned offset from a substrate, wherein:
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each spring is attached between a corresponding stationary structure and a corresponding movable segment, said stationary structure fixed with respect to the substrate;
each movable segment has an outer surface and is adapted to move with respect to the substrate substantially along a normal to the outer surface;
at least one movable segment has a hexagonal shape; and
exactly three springs are attached to the at least one movable segment such that each of the three springs is attached to a different stationary structure. - View Dependent Claims (16, 17, 18, 19, 20, 21, 22)
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Specification