Long range travel MEMS actuator
First Claim
1. An electrostatic comb drive actuator for a Micro Electro-Mechanical System (MEMS) device, comprising:
- a flexure spring assembly; and
first and second comb drive assemblies, each coupled to the flexure spring assembly on opposing sides thereof, each of the first and second comb assemblies including;
a fixed comb drive member having an elongate member with comb drive fingers extending from one side thereof; and
a moveable comb drive member having a center beam coupled to the flexure spring assembly and comb drive fingers extending from one side of the center beam towards the comb drive fingers of the fixed comb drive member;
wherein the moveable comb drive member is moveable between a first position in which the comb drive fingers of the moveable comb drive member and the fixed comb drive member are partially overlapped and a second position in which the comb drive fingers of the moveable comb drive member and the fixed comb drive member are interdigitated to cause a displacement of the flexure spring assembly;
wherein the comb drive fingers are divided equally between the first and second comb drive assemblies and placed symmetrically about a symmetry axis of the flexure spring assembly perpendicular to a direction of motion of the moveable comb drive member; and
wherein the first and second comb drive assemblies when electrically energized contribute electrostatic force in the same direction of motion such that the comb drive fingers of the moveable comb drive members of both the first and second comb drive assemblies simultaneously move towards the comb drive fingers of the respective fixed comb drive members of the first and second comb drive assemblies.
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Accused Products
Abstract
An electrostatic comb drive actuator for a MEMS device includes a flexure spring assembly and first and second comb drive assemblies, each coupled to the flexure spring assembly on opposing sides thereof. Each of the first and second comb assemblies includes fixed comb drive fingers and moveable comb drive fingers coupled to the flexure spring assembly and extending towards the fixed comb drive fingers. The comb drive fingers are divided equally between the first and second comb drive assemblies and placed symmetrically about a symmetry axis of the flexure spring assembly. When electrically energized, the moveable comb drive fingers of both the first and second comb drive assemblies simultaneously move towards the fixed comb drive fingers of the first and second comb drive assemblies.
11 Citations
24 Claims
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1. An electrostatic comb drive actuator for a Micro Electro-Mechanical System (MEMS) device, comprising:
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a flexure spring assembly; and first and second comb drive assemblies, each coupled to the flexure spring assembly on opposing sides thereof, each of the first and second comb assemblies including; a fixed comb drive member having an elongate member with comb drive fingers extending from one side thereof; and a moveable comb drive member having a center beam coupled to the flexure spring assembly and comb drive fingers extending from one side of the center beam towards the comb drive fingers of the fixed comb drive member; wherein the moveable comb drive member is moveable between a first position in which the comb drive fingers of the moveable comb drive member and the fixed comb drive member are partially overlapped and a second position in which the comb drive fingers of the moveable comb drive member and the fixed comb drive member are interdigitated to cause a displacement of the flexure spring assembly; wherein the comb drive fingers are divided equally between the first and second comb drive assemblies and placed symmetrically about a symmetry axis of the flexure spring assembly perpendicular to a direction of motion of the moveable comb drive member; and wherein the first and second comb drive assemblies when electrically energized contribute electrostatic force in the same direction of motion such that the comb drive fingers of the moveable comb drive members of both the first and second comb drive assemblies simultaneously move towards the comb drive fingers of the respective fixed comb drive members of the first and second comb drive assemblies. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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8. A Micro Electro-Mechanical System (MEMS) device, comprising:
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an electrostatic comb drive actuator including; a flexure spring assembly; and first and second comb drive assemblies, each coupled to the flexure spring assembly on opposing sides thereof, each of the first and second comb assemblies including; a fixed comb drive member having an elongate member with comb drive fingers extending from one side thereof; and a moveable comb drive member having a center beam coupled to the flexure spring assembly and comb drive fingers extending from one side of the center beam towards the comb drive fingers of the fixed comb drive member; wherein the moveable comb drive member is moveable between a first position in which the comb drive fingers of the moveable comb drive member and the fixed comb drive member are partially overlapped and a second position in which the comb drive fingers of the moveable comb drive member and the fixed comb drive member are interdigitated to cause a displacement of the flexure spring member; wherein the comb drive fingers are divided equally between the first and second comb drive assemblies and placed symmetrically about a symmetry axis of the flexure spring assembly perpendicular to a direction of motion of the moveable comb drive member; and wherein the first and second comb drive assemblies when electrically energized contribute electrostatic force in the same direction of motion such that the comb drive fingers of the moveable comb drive members of both the first and second comb drive assemblies simultaneously move towards the comb drive fingers of the respective fixed comb drive members of the first and second comb drive assemblies; a displacement multiplier coupled to the flexure spring assembly of the electrostatic comb drive actuator, the displacement multiplier including; a pair of springs symmetrical about a central axis of the displacement multiplier parallel to a direction of force applied by the electrostatic comb drive actuator to the displacement multiplier as a result of the displacement of the flexure spring assembly, each of the springs being stiff in the direction of the force and compliant in a direction perpendicular to the direction of the force; a pair of angled beam members symmetrical about the central axis and each having a first end coupled to a corresponding one of the pair of springs; a pair of pivots symmetrical about the central axis and each coupled to a corresponding one of the pair of angled beam members at a respective pivot point to allow rotation of the pair of angled beam members in response to motion of the pair of springs; a first pair of hinges symmetrical about the central axis and each coupled to a second end of a corresponding one of the pair of angled beam members; a pair of rigid body members symmetrical about the central axis and each having a first end coupled to a corresponding one of the first pair of hinges; and a second pair of hinges symmetrical about the central axis and each coupled to a second end of a corresponding one of the pair of rigid body members, the first and second pairs of hinges allowing rotation of the pair of rigid body members in response to motion of the pair of springs; and a MEMS moveable element coupled between the second pair of hinges; wherein the force applied by the electrostatic comb drive actuator on the displacement multiplier causes an amplified displacement of the MEMS moveable element with respect to the displacement of the flexure spring assembly. - View Dependent Claims (9, 10, 11, 12, 13, 14, 15, 16, 17)
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18. A displacement multiplier for use within a Micro Electro-Mechanical System (MEMS) device, comprising:
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a pair of springs symmetrical about a central axis of the displacement multiplier parallel to a direction of a force applied to the displacement multiplier, each of the springs being stiff in the direction of the force and compliant in a direction perpendicular to the direction of the force; a pair of angled beam members symmetrical about the central axis and each having a first end coupled to a corresponding one of the pair of springs; a pair of pivots symmetrical about the central axis and each coupled to a corresponding one of the pair of angled beam members at a respective pivot point to allow rotation of the pair of angled beam members in response to motion of the pair of springs; a first pair of hinges symmetrical about the central axis and each coupled to a second end of a corresponding one of the pair of angled beam members; a pair of rigid body members symmetrical about the central axis and each having a first end coupled to a corresponding one of the first pair of hinges; and a second pair of hinges symmetrical about the central axis and each coupled to a second end of a corresponding one of the pair of rigid body members, the first and second pairs of hinges allowing rotation of the pair of rigid body members in response to motion of the pair of springs. - View Dependent Claims (19, 20, 21, 22, 23, 24)
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Specification