US5629918A — Electromagnetically actuated micromachined flap

Claim 1

Independent Claim 110 words

A microelectromechanical magnetic actuator comprising: a substrate having a surface; a micromachined flap defined from said surface of said substrate and separated therefrom; at least one micromachined cantilevered beam defined from said surface of substrate coupling said flap to said substrate; a magnetic layer disposed on said flap; and a selectively actuatable magnetic field source disposed proximate to said actuator to create a magnetic field in the vicinity of said flap to bend said flap on said cantilevered beam in a predetermined direction to the plane of said surface of said substrate, whereby a magnetically actuated flap is provided which is selectively disposable out of said surface of said substrate.

Claim 2

Dependent Claim 110 words

A microelectromechanical magnetic actuator comprising: a substrate having a surface; a micromachined flap defined from said surface of said substrate and separated therefrom; at least one micromachined cantilevered beam defined from said surface of substrate coupling said flap to said substrate; a magnetic layer disposed on said flap; and a selectively actuatable magnetic field source disposed proximate to said actuator to create a magnetic field in the vicinity of said flap to bend said flap on said cantilevered beam in a predetermined direction to the plane of said surface of said substrate, whereby a magnetically actuated flap is provided which is selectively disposable out of said surface of said substrate.

Claim 3

Dependent Claim 12 words

The actuator of claim 1 wherein said magnetic source is an electromagnet.

Claim 4

Dependent Claim 19 words

The actuator of claim 1 wherein said magnetic layer is comprised of a magnetic coil disposed on said flap.

Claim 5

Dependent Claim 45 words

The actuator of claim 3 further comprising a current source and wherein said magnetic coil is coupled to said source of current by conductive lines extending from said magnetic coil to said current source, said lines being disposed along said at least one cantilevered beam.

Claim 6

Dependent Claim 13 words

The actuator of claim 3 wherein said magnetic source is a permanent magnet.

Claim 7

Dependent Claim 20 words

The actuator of claim 3 wherein said magnetic field source comprises at least one magnetic coils disposed on said substrate.

Claim 8

Dependent Claim 17 words

The actuator of claim 3 further comprising a plurality of said magnetic coils disposed on said flap.

Claim 9

Dependent Claim 20 words

The actuator of claim 7 wherein said magnetic field source comprises at least one magnetic coils disposed on said substrate.

Claim 10

Dependent Claim 25 words

The actuator of claim 1 wherein said flap has a plurality of holes defined therein to facilitate separation of said flap from said underlying substrate.

Claim 11

Dependent Claim 23 words

The actuator of claim 1 wherein said predetermined direction has at least a component which is out of the plane of said substrate.

Claim 12

Dependent Claim 22 words

The actuator of claim 1 wherein said predetermined direction has at least a component which is in the plane of said substrate.

Claim 13

Dependent Claim 20 words

The actuator of claim 1 wherein said flap is optically opaque so that said actuator functions as an optical shutter.

Claim 14

Dependent Claim 20 words

The actuator of claim 1 wherein at least two cantilevered beams are provided to couple said flap to said substrate.

Claim 15

Dependent Claim 20 words

The actuator of claim 1 wherein said flap is optically reflective so that said actuator functions as an optical mirror.

Claim 16

Dependent Claim 18 words

The actuator of claim 14 further comprising a reflective layer disposed on said magnetic layer of said flap.

Claim 17

Dependent Claim 15 words

The actuator of claim 1 wherein said magnetic layer is comprised of a permanent magnet.

Claim 18

Dependent Claim 14 words

The actuator of claim 16 wherein said permanent magnet is a layer of Permalloy.

Claim 19

Dependent Claim 13 words

The actuator of claim 16 wherein said permanent magnet has an alterable polarity.

Claim 20

Dependent Claim 11 words

The actuator of claim 1 wherein said cantilevered beams are linear.

Claim 21

Dependent Claim 11 words

The actuator of claim 1 wherein said cantilevered beams are serpentine.

Claim 22

Dependent Claim 99 words

An improvement in a method of fabricating a microelectromagnetic magnetic actuator, said improvement comprising: providing a substantially completed microelectromechanical magnetic actuator on a sacrificial layer disposed on an underlying substrate; removing said sacrificial layer upon which said microelectromechanical magnetic actuator has been fabricated by etching away said sacrificial layer through at least one opening defined through said microelectromechanical magnetic actuator to expose said underlying sacrificial layer; and drying said microelectromechanical magnetic actuator while simultaneously actuating said microelectromechanical magnetic actuator to maintain the released portions of said actuator out of contact with said underlying substrate until said drying is complete.

Claim 23

Dependent Claim 99 words

An improvement in a method of fabricating a microelectromagnetic magnetic actuator, said improvement comprising: providing a substantially completed microelectromechanical magnetic actuator on a sacrificial layer disposed on an underlying substrate; removing said sacrificial layer upon which said microelectromechanical magnetic actuator has been fabricated by etching away said sacrificial layer through at least one opening defined through said microelectromechanical magnetic actuator to expose said underlying sacrificial layer; and drying said microelectromechanical magnetic actuator while simultaneously actuating said microelectromechanical magnetic actuator to maintain the released portions of said actuator out of contact with said underlying substrate until said drying is complete.

Claim 24

Dependent Claim 33 words

The improvement of claim 21 where removal of said sacrificial layer is facilitated by providing a plurality of holes through said microelectromechanical magnetic actuator to increase etchant access to said underlying sacrificial layer.

Claim 25

Dependent Claim 122 words

In a method of fabricating a surface micromachine cantilevered layer disposed over an underlying substrate, an improvement comprising: providing said cantilevered layer on a sacrificial layer which in turn is disposed upon said substrate; disposing a magnetic layer on said cantilevered layer; removing said sacrificial layer beneath at least part of said cantilevered layer to release said cantilevered layer from said substrate; and simultaneously maintaining said cantilevered layer apart from said substrate layer by exposing said magnetic layer to a magnetic field which tends to lift said cantilevered layer away from said substrate, said cantilevered being maintained separate from said substrate until removal of said sacrificial layer is completed and possibility of adhesion of said cantilevered layer to said substrate substantially extinguished.

Claim 26

Dependent Claim 122 words

In a method of fabricating a surface micromachine cantilevered layer disposed over an underlying substrate, an improvement comprising: providing said cantilevered layer on a sacrificial layer which in turn is disposed upon said substrate; disposing a magnetic layer on said cantilevered layer; removing said sacrificial layer beneath at least part of said cantilevered layer to release said cantilevered layer from said substrate; and simultaneously maintaining said cantilevered layer apart from said substrate layer by exposing said magnetic layer to a magnetic field which tends to lift said cantilevered layer away from said substrate, said cantilevered being maintained separate from said substrate until removal of said sacrificial layer is completed and possibility of adhesion of said cantilevered layer to said substrate substantially extinguished.

Claim 27

Dependent Claim 15 words

The method of claim 23 where disposing said magnetic layer comprises disposing a Permalloy layer.

Claim 28

Dependent Claim 46 words

The improvement of claim 24 further comprising disposing an organic polymer on at least said cantilevered layer prior to disposition of said magnetic layer thereon and selectively removing said organic polymer layer and said magnetic layer disposed thereon after removal of said sacrificial layer is complete.

Claim 29

Dependent Claim 47 words

The method of claim 23 where removing said sacrificial layer from underneath at least part of said cantilevered layer comprises wet etching said sacrificial layer away and where simultaneously maintaining said cantilevered layer out of contact with said substrate is performed until said microelectromagnetic device is dried.

Claim 30

Dependent Claim 46 words

The improvement of claim 26 further comprising disposing an organic polymer on at least said cantilevered layer prior to disposition of said magnetic layer thereon and selectively removing said organic polymer layer and said magnetic layer disposed thereon after removal of said sacrificial layer is complete.

Claim 31

Dependent Claim 22 words

The improvement of claim 27 where removing said organic polymer is performed with a dry plasma etch so that stiction is avoided.

Claim 32

Dependent Claim 83 words

In a method of controlling flow of a fluid across a surface of an object an improvement comprising: disposing a plurality of microelectromechanical actuators on said surface, each having a selectively operable flap extendable in a direction out of said surface into a boundary layer above said surface over which said flow is established; and selectively actuating at least some of said plurality of microelectromechanical actuators to dispose their corresponding flaps into said boundary layer to thereby affect said flow of said fluid.

Claim 33

Dependent Claim 83 words

In a method of controlling flow of a fluid across a surface of an object an improvement comprising: disposing a plurality of microelectromechanical actuators on said surface, each having a selectively operable flap extendable in a direction out of said surface into a boundary layer above said surface over which said flow is established; and selectively actuating at least some of said plurality of microelectromechanical actuators to dispose their corresponding flaps into said boundary layer to thereby affect said flow of said fluid.

Claim 34

Dependent Claim 41 words

The method of claim 29 where selectively disposing said corresponding flaps into said boundary layer at a position upstream from expected flow separation and oscillating said flaps to affect flow separation of said fluid at a point downstream from said flaps.

Claim 35

Dependent Claim 39 words

The improvement of claim 29 where selectively disposing said corresponding flaps into said boundary layer comprises electromagnetically actuating said flaps to bend said flaps into said boundary layer out to the plane of said actuator to affect turbulent flow.

Claim 36

Dependent Claim 31 words

The improvement of claim 29 wherein said surface is an airplane control surface and where selectively disposing said corresponding flaps serve to provide a control force to said airplane control surface.

Claim 37

Dependent Claim 23 words

The method of claim 29 where selectively disposing said corresponding flaps into said boundary layer serves to reduce fluid drag of said surface.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	2000-05-12	2000-11-11	2001-05-13	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	2004-05-12	2004-11-11	2005-05-13	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	2008-05-12	2008-11-11	2009-05-13	$7700.00	Window Closed / Lapsed

Electromagnetically actuated micromachined flap

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