CN1961244A

CN1961244A - Flexible electrostatic actuator

Info

Publication number: CN1961244A
Application number: CN 200580017738
Authority: CN
Inventors: 戴维·E·道施; 斯考特·H·古德温
Original assignee: Research Triangle Institute
Current assignee: Research Triangle Institute
Priority date: 2004-04-23
Filing date: 2005-04-25
Publication date: 2007-05-09
Anticipated expiration: 2025-04-25
Also published as: CN101471203A; CN101471203B; CN100451737C

Abstract

An electrostatic actuator having a base (10) including a first electrode (20), and having a flexible membrane (50) including at least two material layers of different materials in contact with each other. At least one of the material layers includes a second electrode (40) electrically isolated from the first electrode. The flexible membrane includes a fixed end where the flexible membrane connects to the base and a free end opposite the fixed end. In the flexible membrane, the second electrode has at least first and second portions separated by a third portion an in combination defining a step provided in a vicinity of the fixed end. The first step is closest to the fixed end and separated by a shorter distance from the first electrode than the second portion. A stiffening member (310) can be disposed on the flexible membrane toward the free end of the flexible membrane. The electrostatic actuator can include an elongated orifice (420,320) extending through the base and extending along a direction away from the fixed end. The first electrode of the base can extends past an end of the second electrode of the flexible membrane in a direction defined toward the fixed end. The flexible membrane can include a peripheral or side cut out configured to communicate to an interior of the flexible membrane.

Description

Flexible electrostatic actuator

The cross reference of related application

The application relates to and the name that requires to submit on April 23rd, 2004 is called " ReleasingStructures (releasing structure) ", sequence number is No 60/564,594 U.S. Provisional Application No., the full content of this provisional application is incorporated into this by reference.The application relates to and the name that requires to submit on April 23rd, 2004 is called " Electrostatic Valve withNon-Wetting Layer (the static valve with non-infiltration layer) ", sequence number is No60/564,580 U.S. Provisional Application No., the full content of this provisional application is incorporated into this by reference.The application relates to and the name that requires to submit on April 23rd, 2004 is called " Flow Control for Higher Operating Pressures (being used for the flow control of higher on-stream pressure) ", sequence number is No 60/564,573 U.S. Provisional Application No., the full content of this provisional application is incorporated into this by reference.The application relates to and the name that requires to submit on April 23rd, 2004 is called " Strong and Flexible Valve Closing forFlexible Electrostatic Film (the strong flexible valve of closing for the flexible electrostatic film) ", sequence number is No 60/564,572 U.S. Provisional Application No., the full content of this provisional application is incorporated into this by reference.The application relates to and the name that requires to submit on April 23rd, 2004 is called " Higher Operating Voltages for Flexible Film Actuators (higher operation voltage that is used for the flexible membrane driver) ", sequence number is No 60/564,571 U.S. Provisional Application No., the full content of this provisional application is incorporated into this by reference.The application relates to US Patent No 6,236,491, and the full content of this patent is incorporated into this by reference.The application relates to U.S. Patent No. 6,456,420, and the full content of this patent is incorporated into this by reference.

Technical field

The present invention relates to micro electronmechanical exciter structure, and relate more specifically to little exciter structure that processes of static excitation.

Background technology

The progress of thin film technique makes that complicated integrated circuit is developed.This semiconductor technology is adjusted and forms MEMS (micro electro mechanical system) (MEMS) structure.Form a lot of MEMS devices not of the same race, comprised microsensor, miniature gears, micro motor and other micro-device that manufactures and designs.For example, microcantilever has been used for applying rotatory mechanical force to rotate micro-machined spring and gear.Use electromagnetic field to drive micro motor.Use piezoelectric forces to come controllably to move micro-machined structure.The controlled thermal expansion of driver or other MEMS parts has been used to be formed for driving the power of microdevice.

The flexible complex electrostatic actuator generally includes the flexible complex of being made by flexible electrode and insulator.Flexible complex is attached to the substrate that comprises fixed electorde also can be towards substrate deflection under electrostatic force.Insulator is arranged between flexible complex and the substrate to avoid the short circuit of flexible electrode and fixed electorde.By apply voltage between flexible electrode and fixed electorde, flexible complex is pulled to substrate by electrostatic attraction.When not having voltage, normally the stress in the flexible complex curls flexible complex and away from substrate.The application of flexible complex driver comprises isolating switch, minitype actuator, electric switch and the variable radio frequency capacitor of gas or fluid valve, optical shutter, radio-frequency phase shifter, infrared detector.

U.S. Patent No. 6,236 has been shown, 491 conventional driver among Fig. 1.Driver wherein comprises fixed complex 130 and flexible complex 50.Fixed complex 130 comprises substrate 10, fixed electorde 20 and insulated substrate body 30.The flexible complex 50 that comprises flexible electrode 40 places fixed complex 130 tops, and comprises fixed part 70, center section 80 and end portion 100.Fixed part 70 is attached to following substrate 10 or middle layer basically.Center section 80 extends and keeps in position under the situation that does not apply electrostatic force from fixed part 70, thereby limits air gap 120 between plane surface below and the center section 80.

When finishing driver, center section 80 and end portion 100 all discharge from following fixed complex 130.End portion 100 moves freely in operation, curl and away from following plane surface and change and its spacing.In case flexible complex 50 bendings, center section 80 can be curled towards following plane surface, curl or keep constant spacing with it away from following plane surface.

On xsect, flexible complex 50 can have the multilayer that comprises at least one electrode layer 40, and can comprise that biasing layer is mechanically to strengthen above the flexible complex part to fixed part 70.The layout of the thickness of the number of layer, layer, layer and the selection of institute's materials used can be chosen as and make flexible complex can curl towards following microelectronic substrate electrode, curl or keeping parallelism with it away from following microelectronic substrate electrode ground.

Flexible complex 50 generally includes polymer film 60, flexible electrode 40 and another polymer film 62.After the releasing layer 34 that uses when remove making this structure, different thermal expansivity mechanically is biased to center section 80 and end portion 100 and curls and away from following surface 32 between each layer of flexible complex 50.End portion 100 can be curled with variable or constant radius-of-curvature.

Because center section and end portion are constructed similarly, different thermal expansivity tends to make center section to curl between electrode 40 and the polymer film.Yet, can setover control structure so that offset the curling tendency of center section after removing releasing layer and keep center section in position to be used as at the extra play that applies polymer film, metal or other material on the second layer polymer film alternatively.Perhaps, can apply inherent stress to strengthen curling tendency and to increase distance between flexible complex and the substrate surface to material.

Although conventional driver is very exquisite, also have the reliability and the performance of a lot of problems affect drivers.These problems described in detail below are solved in each embodiment of the present invention.

Summary of the invention

A target of the present invention provides a kind of driver of closing under the operating voltage condition that reduces, the described operating voltage that reduces is unlikely to cause dielectric breakdown in the insulating material of driver.

Another target of the present invention provides a kind of driver, and its flexible membrane structurally strengthens to keep closing with respect to pressure fluid.

Another target of the present invention provides a kind of driver, and it is closed voltage and is lowered for the given institute hydrodynamic pressure that applies, and therefore unlikelyly causes dielectric breakdown in the insulating material of driver.

Another target of the present invention is to reduce the flexible membrane that foreign matter is adhered to driver, and therefore flexible membrane more predictable motion under electric biasing is provided.

Another target of the present invention is the zone of reducing local high electric field in the driver, and therefore unlikelyly causes dielectric breakdown in the insulating material of driver.

These and other target provides in an embodiment of the present invention.

In one exemplary embodiment, provide a kind of electrostatic actuator, it has the base portion that comprises first electrode, and has flexible membrane, and this flexible membrane comprises at least two material layers of contacted different materials each other.At least one material layer comprises second electrode of isolating with first electrode electricity.Flexible membrane comprises anchor portion and the free end opposite with anchor portion that is connected to base portion.In flexible membrane, second electrode has at least by separated first and second parts of third part, and first and second parts limit near the step that is located at the anchor portion together.The most close anchor portion of first step, and compare with the shorter distance and first electrode separation with second portion and to open.

In another exemplary embodiment, a kind of electrostatic actuator is provided, it has the base portion that comprises first electrode, and has flexible membrane, and this flexible membrane comprises at least two material layers of contacted different materials each other.At least one material layer comprises second electrode of isolating with first electrode electricity.Flexible membrane comprises anchor portion and the free end opposite with anchor portion that is connected to base portion.As the part of flexible membrane, reinforcement is arranged on the flexible membrane away from anchor portion.

In another exemplary embodiment, a kind of electrostatic actuator is provided, it has the base portion that comprises first electrode, and has flexible membrane, and this flexible membrane comprises at least two material layers of contacted different materials each other.At least one material layer comprises second electrode of isolating with first electrode electricity.Flexible membrane comprises anchor portion and the free end opposite with anchor portion that is connected to base portion.Electrostatic actuator comprises and extends through base portion and along the elongated hole of extending away from the direction of anchor portion.

In another exemplary embodiment, a kind of electrostatic actuator is provided, it has the base portion that comprises first electrode, and has flexible membrane, and this flexible membrane comprises at least two material layers of contacted different materials each other.At least one material layer comprises second electrode of isolating with first electrode electricity.Flexible membrane comprises anchor portion and the free end opposite with anchor portion that is connected to base portion.First electrode of base portion is at an end of second electrode of extend through flexible membrane on the direction of anchor portion.

In another exemplary embodiment, a kind of electrostatic actuator is provided, it has the base portion that comprises first electrode, and has flexible membrane, and this flexible membrane comprises at least two material layers of contacted different materials each other.At least one material layer comprises second electrode of isolating with first electrode electricity.Flexible membrane comprises anchor portion and the free end opposite with anchor portion that is connected to base portion.Flexible membrane comprises and is configured to the periphery or the side cutout (cutout) that communicate with flexible membrane inside.

In another exemplary embodiment, a kind of electrostatic actuator is provided, it has the base portion that comprises first electrode, and has flexible membrane, and this flexible membrane comprises at least two material layers of contacted different materials each other.At least one material layer comprises second electrode of isolating with first electrode electricity.Flexible membrane comprises anchor portion and the free end opposite with anchor portion that is connected to base portion.Driver has the non-infiltration compound at least one that is arranged among flexible membrane upper surface, flexible membrane lower surface and the base portion upper surface.

Be to be understood that aforementioned general description of the present invention and following detailed all are exemplary, but not be for restriction of the present invention.

Description of drawings

With reference to understanding the present invention better below in conjunction with the detailed description of accompanying drawing, be easy to obtain therefore that the present invention understands more completely and a lot of attendant advantages, in the accompanying drawings:

Fig. 1 is the schematic side elevation that conventional micromechanical actuator is shown;

Fig. 2 is the schematic side elevation that illustrates according to micromechanical actuator of the present invention, and this driver utilizes staged to reduce slit between flexible membrane and the stationary substrate layer;

Fig. 3 is the perspective schematic view that illustrates according to micromechanical actuator of the present invention, and this driver comprises reinforcement;

Fig. 4 A is the perspective schematic view that illustrates according to micromechanical actuator of the present invention, and this driver comprises the taper valve opening;

Fig. 4 B is the perspective schematic view that illustrates according to micromechanical actuator of the present invention, and this driver comprises elongated valve opening;

Fig. 5 is the perspective schematic view that illustrates according to micromechanical actuator of the present invention, and this driver comprises the deflection piece on the valve opening;

Fig. 6 is the schematic, exploded that illustrates according to micromechanical actuator of the present invention, and this driver comprises the deflection piece on the valve opening;

Fig. 7 is the schematic side elevation that illustrates according to micromechanical actuator of the present invention, and this driver comprises the non-infiltration layer on flexible membrane and the stationary substrate layer;

Fig. 8 A is the schematic side elevation that conventional micromechanical actuator is shown, and wherein shows local electric field and strengthens point;

Fig. 8 B is the schematic side elevation that illustrates according to micromechanical actuator of the present invention, has wherein shifted local electric field and has strengthened point;

Fig. 8 C is the schematic top view that illustrates according to toothing of the present invention, and this toothing connects flexible membrane and stationary substrate layer;

Fig. 9 is the SEM microphoto that illustrates according to toothing of the present invention;

Figure 10 is the perspective schematic view that illustrates according to micromechanical actuator of the present invention, and this driver comprises the variation on the flexible membrane downside surface;

Figure 11 A is the schematic side elevation that illustrates according to micromechanical actuator of the present invention, and this driver comprises the electric switch contact by the micromechanical actuator contact; With

Figure 11 B is the schematic side elevation that illustrates according to micromechanical actuator of the present invention, and this driver forms the optical device by this micromechanical actuator excitation.

Embodiment

Referring now to accompanying drawing, wherein same Reference numeral is at the sensible same or corresponding parts of institute's drawings attached acceptance of the bid, and various aspects of the present invention are described by following illustrative embodiment of the present invention.

" operating voltage " of driver is commonly referred to as and puts between fixed electorde and the flexible electrode (such as the electrode among Fig. 2 20,40) with the electromotive force of closing driver and limited by " beginning the voltage of leaving behind " usually, and " beginning the voltage of leaving behind " refers to the electromotive force that applies to begin to close.More specifically, beginning " leaving behind " voltage is pulled to flexible complex 50 with fixed complex 130 and contacts.After beginning contact, can use lower voltage to come little by little remainder with flexible complex 50 to be pulled to and contact, thereby close driver in for example mode of slide fastener shape with fixed complex 130.

In one embodiment of the invention, as shown in Figure 2,, can reduce the operating voltage of driver by at least a portion slit 120 away from end portion 100 between

electrode

20 and 40 is narrowed down.In this embodiment, deposit and composition releasing layer 34 (for the purpose of example illustrate and the driver of working in do not have), make the shape of downside surface of shape copying flexible complex 50 of releasing layer end face.As mentioned above, the removal of releasing layer allows flexible complex 50 to curl, do not form bicker as shown in Figure 1 between the centre of flexible complex 50 and end portion 80,100 under have to setover away from fixed electorde 20 ground.

The thickness that between fixing and

flexible complex

130,50, obtains determined slit 120 influences be used for beginning the leaving behind voltage of leaving behind that begins of flexible membrane 50 by releasing layer 34.Releasing layer usually can be thick for 2000 .For the flexible complex 50 that tightly curls, may need the voltage of leaving behind that begins of 200V.The electric field of resulting 10MV/cm has surpassed the disruptive strength of big multi-dielectric material.Thin releasing layer 34 has reduced the slit 120 between flexibility and the fixed complex 50,130, begins the voltage of leaving behind thereby reduced.Yet Bao releasing layer (for example much smaller than 1000 ) can cause because uncontinuity or defective in the releasing layer can hinder the release of flexible complex some parts and cause being difficult to discharge driver excessively.

In this embodiment of the present invention, the thickness of releasing layer 34 reduces in distance fixed part 70 a distance, as schematically illustrated among Fig. 2.Like this, the electrode 40 of resulting flexible complex 50 separates a reduction with underlayer electrode 20 in those zones of more close fixed part 70, thereby forms the slit 120 of classification.Thereby, near fixed part 70, form less slit, just produced the lower voltage of leaving behind that begins, and the main body of releasing layer 34 is sufficiently thick in to guarantee suitable release etch.

In an exemplary example, the main body of releasing layer 34 can be thick for 1000-2000 , and can be thick for 100 to 1000  in the classification part of releasing layer 34.In order to form the classification part, releasing layer 34 deposit by stages; Near the fixed part 70 of flexible complex 50, can carry out the bigger etching of releasing layer, and/or can provide on the thickness more that " simulation " reduces with grey-scale lithography.Though Fig. 2 only shows two steps, but can form a plurality of steps, for example 2000 , 1000 , 500  and 250  that the follow area that minimizes the attenuation part of releasing layer is reduced to its minimum potential range to minimize the voltage of leaving behind in next-door neighbour's fixed part office with the slit simultaneously.For example, be 2000  and close the flexible membrane driver that voltage is 72V, near fixed part, releasing layer thickness is reduced to 500  and just will closes voltage and be decreased to 64V, reduce about 10% for releasing layer thickness.Be 2000  and close the driver that voltage is 310V for releasing layer thickness, releasing layer thickness is reduced to 500  just this voltage is decreased to 245V, reduce about 20%.

A kind of method that forms step will be the deposit of covering of release film, be repeatedly mask subsequently, be the release film that local etching exposes after each mask.Perhaps, if come the deposit release film with the technology of lifting away from, then repeatedly mask and deposit can be used for forming by stages releasing layer.

Grey-scale lithography is to form the third mode that simulation (promptly more level and smooth) changes on the thickness of releasing layer.Grey-scale lithography relates to the formation photomask, and this photomask has the very fine pattern that changes or have the opaque and transparent region that can not differentiate one to one on etchant resist on the opacity of masking film.In either case; exposure dose is chosen as just partly to develop and removes the thickness of resist under the mask gray level region; because the UV radiant quantity of irradiation etchant resist stands horizontal transformation on the surface of wafer, the never exposure fully of opaque material (removing resist during developing fully) is to the complete opaque nothing exposure of mask (and not removing resist).Thereby the thickness of etchant resist gradually changes, rather than subvertical step shown in Figure 2.For example, in one embodiment of the invention, the transition energy of inclination is sent to following releasing layer with the RIE step, and described RIE step is with roughly the same speed etching photomask and releasing layer.

In another embodiment of the present invention, as schematically illustrated among Fig. 3, driver is provided as gas or fluid valve, and keeps closing and do not enlarge markedly working pressure with respect to bigger pressure." pressure " refers to the power that the downside surface with respect to flexible complex 50 applies by gas or liquid, and described gas or liquid flow and clash into this downside surface towards the downside surface of flexible complex 50 by the hole in the fixed complex 130 320.

As shown in Figure 3, the flexible complex 50 among this embodiment comprises hole cap 310, its can by be arranged on the flexible complex 50 or within one deck reinforcing material form.Reinforcing material can form by deposited metal with by lifting away from the technology composition, perhaps forms by deposit polymkeric substance, oxide or nitride layer and by chemistry or plasma etching composition.Reinforcing material can be a metal, such as Cr, Au, Au alloy or Al, but also can use other metal and nonmetal according to the present invention, comprises for example oxide, nitride or polyimide.Except forming hole cap 310, when not applying biasing, one deck reinforcing material in the center section influences the angle of outlet of flexible complex.If reinforcing material conducts electricity, then voltage can be applied to hole cap 310 between flexibility and fixed complex 50,130, to produce or the increase electrostatic attraction.The reinforcing material of conduction can be electrically connected to flexible electrode in the flexible complex by etched path.In certain embodiments, flexible electrode can be discontinuous on the hole of fixed complex.By being electrically connected the enhancement layer of conduction, around the hole of fixed complex, provide additional electrostatic force.

Whether no matter have voltage to put on hole cap 310, hole cap 310 all provides more firm sealing by near the physical strength that has increase hole 320.The physical strength that cap increases allows the electrostatic force of larger area surround electrode to help keep flexible complex 50 with respect to fixed complex 130.In single driver, can comprise a plurality of holes and corresponding hole cap.Preferably, comprise the area of the area of hole cap greater than the hole.If the area of hole cap is less than the area in hole, the overall hardness of flexible complex 50 will only increase very little amount so, and can not obtain the ability of increased pressure.Though be depicted as the hole cap, except close those zones in hole, reinforcement can also put on other zone of flexible complex 50.The variable of control punch cap and flexible complex 50 hardness comprise that lap between shape, hole cap and the aperture of thickness, hole cap 310 of the selection of reinforcing material, the mechanical attributes of reinforcing material (for example Young modulus), material and hole cap 310 are arranged in that flexible complex (end face or bottom surface) is gone up or within.The preferable range of area ratio is from 1.4 to 9 between metal reinforcements and the aperture, but other scope also is applicable to the present invention.The preferable range of reinforcement (for example hole cap) thickness is from 0.5 μ m to 1.5 μ m, but other scope also is applicable to the present invention.A kind of preferred metal is the gold with chromium adhesion layer.The hole cap shaped that is fit to comprises circular cap or the many row parallel bar parallel with driver rotating shaft (hinge) (Width).Illustrating, is 70 microns valve driver for hole dimension, uses to strengthen cap the pressure hold facility is increased 20 to 50%.

Shown in Fig. 4 A, 4B and 5, another embodiment of the present invention by with air-flow or liquid conductance to the more end portion (be free end) of flexible complex 50 away from fixed part 70, reduced the operating voltage that is used for closed flexible membrane.Air-flow or liquid stream by the hole are exerted pressure with respect to the downside of flexible complex 50, thereby stop flexible complex 50 near fixed complex 130.

According to the present invention, the driver of Fig. 4 A can arrive farther end portion with direct fluid by the shape of revising hole 420.Bellmouth, tri-angle-holed 420 such as shown in Fig. 4 A, have towards the fixed part 70 of flexible complex 50 arrange single most advanced and sophisticated 430.Direct fluid by will passing the hole is away from the fixed part 70 of flexible complex, hole 420 made things convenient for driver begin close.When driver cut out, flexible complex 50 was just reduced by the total area of air-flow or liquid stream bump, and electrostatic force increases along with the minimizing of spacing, thereby had made things convenient for the closure of flexible complex 50 on the remainder in hole 420.Preferably but not necessarily, tri-angle-holed 420 should be at least the twice of the parallel size in this direction of this triangle with the vertical size of the stiff end of flexible complex, and more preferably are 3 times, thereby form the elongated triangular shape shown in Fig. 4 A.

According to alternative embodiment, can distribution equably on the lower surface of flexible complex by the flow in hole.Shown in Fig. 4 B, this realizes by form strip (oblongshaped) hole in fixed complex.Dispense flow rate will play with the deflection flow and similarly act on (as mentioned above and as shown in Figure 4), because dispense flow rate concentrates on minimizing the flow in the zone of more close flexible complex center section.When having circular port in the heart in the fixed complex below flexible complex, bigger flow will concentrate on more close center section.This bigger concentrated flow will reduce the ability on the flexible complex position of circular port (specifically) capping fixed complex surface.The dispense flow rate that provides by the strip hole will increase the ability of closing on the hole.In addition, have elongated hole of the same area with circular port and will have less pitch-row that flexible complex need cross in the position in hole from (be that circular port is wideer at the place, hole site, the strip hole is narrower).This less distance changes at place, hole site and the contacted increase flexible electrode of fixed complex area, and this has increased the electrostatic force that keeps flexible complex 50 with respect to fixed complex 130.The width general in strip hole still has longer length less than the width of common circular port so that the flow area identical with circular port to be provided widely.In certain embodiments, the length in strip hole can be 30 to 90% of flexible complex length.

In another embodiment of the present invention, the driver of Fig. 5 adopts deflection piece 590 with the more end portion deflection towards flexible complex 50 of air-flow or liquid stream.Like this, deflection piece 590 is the more terminal or free part of fluid conductance to flexible complex 50, thereby made things convenient for driver to close in the mode in the above-mentioned example.Deflection piece 590 can leave flexible complex 50 with portion gas or the complete deflection of fluid; Thereby and reduced from inhibition pressure away from the fluid of flexible complex 50 downside surface normal directions stream.

In this embodiment of the present invention, deflection piece 590 can for example be arranged as the cantilevered fin that extends on hole 320; And machinery passive (promptly not being electrically driven (operated)).Schematically illustrated as Fig. 6, deflection piece 590 can comprise the chromium layer 690 that is arranged between dielectric layer 30 and the substrate 10.Chromium layer 690 can be patterned with the portal lateral dimension of the deflection fin 590 on 320 of qualification.If hole 320 carves from substrate 10 1 lateral erosion of fixed complex, the etching of substrate will stop at chromium and the polyimide film 30 that is exposed in the hole 320 so.Before stopping at releasing layer 34, for example can use oxygen RIE step to come the polyimide film of etch exposed.

A kind of technology that is used for making deflection piece 590 according to the present invention is to utilize to lift away from technology and evaporate on the end face of silicon substrate and composition Cr layer.Then, deposit polyimide basic unit, the fixedly polyimide insulator of deposit subsequently and composition bottom electrode and covering bottom electrode.Deposit and composition releasing layer carry out remaining standard technology sequence subsequently to form the flexible membrane 30 that covers valve opening.Etching silicon afterwards, is carried out O to the back side with the hole (its stop at Cr or polyimide and can be with they etchings) that formation runs through substrate overleaf ₂The RIE step is with the exposure polyimide of etch exposed releasing layer.The Cr deflection piece has prevented that the polyimide on the Cr is etched.In case releasing layer is etched, the fin that is formed in the flexible membrane is exactly freely.Polyimide layer 30 on Cr layer 690 and the Cr (owing to sheltering of Cr do not have etched) is as deflection piece 590.This two-layer (being Cr and polyimide) still is attached to each other.The manufacturing that covers the flexible membrane fin of valve opening can not be subjected to the influence that deflection piece is made.

Another embodiment of the present invention as shown in Figure 7, prevents the static friction of flexible complex 50 and fixed complex 130.If fluid or other impurity are deposited on the driver surface, during electricity operation (opening or closing) static friction can take place so.When keeping flat-shaped required voltage to be removed with respect to fixed complex flexible complex, static friction will stop the curling fixed complex that leaves of flexible complex.For example, if the surface of flexible and fixed complex has been moistened in water or oil immersion, when removing voltage, if owing to the caused surface tension of central fluid layer greater than the recovery stress in the flexible complex, flexible complex will can not curl and leave fixed complex.

In order to reduce static friction, this embodiment of the present invention non-infiltration layer (for example hydrophobic or oleophobic layer) 710,720,730 is arranged among the end face of the bottom surface of end face, flexible complex 50 of fixed complex 130 and flexible complex 50 at least one or a plurality of on.Perhaps, if given non-infiltration material has suitable dielectric and engineering properties, perhaps vice versa, and non-infiltration layer 710,720,730 be replaced or be used as to layer 30,60,62 can by non-infiltration layer 710,720,730.

Non-infiltration layer 710,720,730 prevents the adhesion of the infiltration composition (for example water or oil) do not expected; Perhaps make this composition form the liquid pearl and discontinuous film.The non-infiltration layer is described as a kind of increase and is deposited on the contact angle of lip-deep fluid so that fluid forms the material of drop or liquid pearl on this surface.For non-infiltration character, preferably contact angle is greater than 90 °.For low contact angle, fluid will soak into from the teeth outwards or launch and can not form drop or liquid pearl.Infiltration behavior meeting causes the static friction of flexible complex and fixed complex.For example, if water or oil immersion profit are flexible and the surface of fixed complex, when removing voltage, if the surface tension that is caused by the central fluid layer surpasses recovery stress in the flexible complex (cause curl stress), flexible complex will can not curl and leave fixed complex.If the surface be non-infiltration and water or oily Cheng Zhu, static friction can not take place so; In addition, the opening and closing of driver action (curl and trail) will be released liquid pearl or drop the perform region of device.

Static friction is especially general when water or oil are introduced into the driver environment.So lay-by material of the present invention comprises polymkeric substance or other the suitable material that is used for hydrophobic, oleophobic or chemically inert surface.More specifically, polymkeric substance can comprise fluorine-containing compound (teflon for example ^), siloxane polymer (for example dimethyl silicone polymer or PDMS) and from assembled monolayer (SAM), for example octadecylsilane (ODS), dichlorodimethylsilane (DDMS), perfluoro decyltrichlorosilane (FDTS).According to the present invention, these coatings can put on the water-wetted surface that the shifting board device of release exposes, i.e. Gu Ding dielectric (for example polyimide or SiO ₂) and the metal surface, so that the surface that exposes becomes hydrophobic.For example, polymkeric substance can be used as additional spin-coated layer and is integrated in the driver manufacture process; And side by side limited and etching by optics with polyimide layer, this is because can use identical etch chemistries (O for example ₂Plasma).Polymer solution by applying dilution before the crimping polymer layer is also removed (spin off) redundance by centrifuge method, and the non-infiltration layer also can be applied for individual layer; For example, be similar to the tackifier technology that is used for photoresist, wherein unnecessary tackifier are removed only to stay individual layer by centrifuge method.

In certain embodiments, hydrophobic or non-infiltration layer will put on the driver device of release.This will need the polymkeric substance of vapour deposition, for example by physical vapor deposition (for example evaporation), chemical vapour deposition, with spraying or utilize the solution that dilutes very much to carry out dip-coating.

Perhaps, polymer surfaces can be by plasma treatment to change the infiltration behavior on those surfaces.The plasma treatment of polymer surfaces can be from for example knowing in U.S. Patent No. 5,147, the 678 described prior aries; The full content of this patent is incorporated into this by reference.Under the sort of situation, need not other polymkeric substance.For example, can use according to the present invention such as fluorine plasma or chemical plasma and handle (CF for example ₄, CHF ₃, SF ₆, and HF) and so on surface treatment.Can also use hydrogen plasma or chemical treatment (H for example according to the present invention ₂, SiH ₄, CH ₄, organosilane) revise the chemical constitution (by in conjunction with F or H ion) of the water-wetted surface that the shifting board device of release exposes so that the surface hydrophobicity that exposes.

In any case although the progress described in the present invention or use the foregoing description, because the electric field that operating voltage produced of driver can cause the dielectric breakdown in the driver.The measure that prevents dielectric breakdown can allow driver to adopt higher operating voltage.And the potential application of driver can be protected and increase to the minimizing of dielectric breakdown.

One embodiment of the present of invention have solved by the edge of fixing and

flexible electrode

20,40 and the dielectric breakdown that the bight causes.Shown in Fig. 8 A, staircase structure flexible and

fixed electorde

40,20 has caused respective edges/bight 880,890.Compare with the electric field along the plane surface of

electrode

40,20, near the internal field these bights can be improved in these edge/bights 880,890.Although inserted dielectric layer 30, electric field strengthens still can cause dielectric breakdown.

In one embodiment of the invention, form electric field and strengthen edge/bight 880,890 smoothedization of point to prevent that forming electric field strengthens point.A kind of method in smoothing bight is with the micro-fabrication technique deposit of standard and composition bottom electrode, and rotation is deposited on Boping material thinner than the peripheral region on the coboundary of bottom electrode then.Carry out etching by the engraving method that flat-shaped material and bottom electrode is had similar etch-rate then, so that before etching surround electrode any part, remove the upper corner of bottom electrode, with its smoothing.Perhaps, also can use aforesaid grey-scale lithography to come the smoothing bight.

In another embodiment of the present invention, shown in Fig. 8 B, fixed electorde 20 is at extend past flexible electrode 40 on the direction of the fixed part 70 of flexible complex 50.Therefore, concave edge/the bight 880 of flexible electrode 40 is removed, and the convex edge/bight 890 of fixed electorde 20 is relocated, so that flexible electrode 40 no longer is arranged on the edge/bight 890 of fixed electorde 20, and the span of dielectric layer 30 between the terminal edge/bight of

electrode

20,40 increases.

Another embodiment of the present invention shown in Fig. 8 C, has solved by projection that flexible complex 50 is attached to fixed complex 130 or tooth 850 caused dielectric breakdowns.Tooth is preferably the structure in the bottom that is formed at flexible complex, its outstanding dielectric layer that runs through releasing layer and be attached to fixed complex.Tooth forms by the disappearance of releasing layer, makes flexible complex and fixed complex to couple together in the narrow zone vertical and adjacent with fixed area 70.Tooth can be controlled the angle of outlet of (preferably reducing) flexible complex 50 with respect to fixed complex 130.By reducing the angle of outlet, can reduce operating voltage.Tooth 850 defines fixed area 70 extends into zone line 80 during the manufacturing of driver zone.Fig. 9 is the SEM microphoto of flexible complex 50, and wherein flexible complex 50 has been curved to the point of tearing along the end face of tooth.This microphoto shows the relation between tooth and flexible complex 50 and the fixed complex 130.

Because this structure of flexible complex 130, flexible electrode 40 enters the part of tooth effectively downwards, and electric breakdown can occur in the bight of tooth.Three-dimensional bight is formed at the more close substrate of flexible electrode place in the tooth zone, and exists concentrating of electric field and increase owing to the local geometric shape in this bight at this place, bight.Bight by sphering tooth 850 is to produce the tooth 860 shown in Fig. 8 C, and the acutance in bight reduces and the generation of dielectric breakdown also reduces.

In another embodiment of the present invention, flexible complex 50 has the surface along its outer ledge to be changed, such as projection and depression, to alleviate a manufacturing issue relevant with MEMS technology.Figure 10 A shows the top view of the flexible complex 50 that covers with polyimide.Flexible complex 50 has projection 60a along its lateral outer side edge 60c.Projection 60a is depicted as and carries out cylindrical extraction by the transverse edge from flexible complex 50 and remove and form.

In the magnitude of MEMS device, because the power that surface nature causes is occupied an leading position with respect to the power that causes owing to bulk properties usually.Finish Wet-type etching with flexible complex 50 when fixed complex 130 discharges, carry out rinsing to remove etchant; And also remove then rinsing residual liquid.If flexible complex 50 is suitably not dry, the surface tension that is caused can be returned the part of flexible complex 50 downwards towards fixed complex 130 deflections.In other words, leave fixed complex 130 after release etch, contact with it owing to the dry surface tension that causes also can cause flexible complex 50 to trail and become towards fixed complex 130 subsequently even flexible complex 50 is curled.

As a result, flexible complex 50 can push fixed complex 130.The static friction that obtains between flexible complex 50 and the fixed complex may be sufficiently strong so that keep compound 50,130 after finishing drying.Avoid the method for this problem to comprise above-mentioned formation non-infiltration layer 710,720 on

dielectric layer

30 and 60; Come etching releasing layer 34 with dry etching, for example based on the RIE of gas; The perhaps supercritical drying of driver.

Supercritical drying has adopted the liquid state of fluid and the critical point between the gaseous state.By with postcritical pressurized with fluid on its critical-point pressure, be heated on the critical point temperature and just changed into gas and can not form liquid gas interface at elevated temperatures then chamber depressurization, supercritical liq.A nonrestrictive example of supercritical drying adopts CO ₂As supercritical fluid.In this example, from tank, take out the driver of rinsing, put into isopropanol bath, put into the methyl alcohol groove then.Yet driver and some methyl alcohol are placed in the overcritical chamber, wherein add liquid CO ₂And chamber is cleaned to only stay CO in chamber ₂Yet supercritical drying is not a perfect craft.Thereby, various liquid (for example water, isopropyl alcohol, methyl alcohol and liquid CO ₂) can be to some extent interact with the surface (for example polyimide surface) of flexible complex 50, so that flexible complex 50 presents different curling and shape.Find out that the crimp energy of flexible complex 50 reverses in potcher, flexible complex curls at described tipper pilot scale figure and enters substrate downwards but not upwards leave substrate.In the case, the edge of flexible complex 50 will contact with fixed complex 130 and see that from above flexible complex will be protruding pillow-like.This can cause during supercritical drying drying process rinse fluid to be trapped in below the flexible complex 50 and the liquid that is detained can cause static friction between flexible complex and the fixed complex 130.

Shown in Figure 10 A, projection 60a reduced shown in the static friction between fixed complex 130 and the flexible complex 50 can be passed through, and described projection makes fluid to flow below the surface in contact zone along outer ledge.Mode as an alternative in addition, shown in Figure 10 B, the static friction between fixed complex 130 and the flexible complex 50 can reduce by placement variation on the surface in contact of transverse edge (for example projection 60d and depression 60b).This variation on the surface in contact of transverse edge for example can form by the releasing layer 34 that forms different-thickness.When structure flexible complex 50 on releasing layer 34, these change transitions are the surface of transverse edge 60c.If flexible complex 50 during drying trails, this variation has just prevented the sealing between transverse edge 60c and the fixed complex 130, thereby makes drying agent (liquid CO for example ₂) can be near any fluid, for example etchant or purificant below flexible complex 50.

Similarly the result promptly during drying prevents the sealing between transverse edge 60c and the fixed complex 130, also can obtain by form projection variation 60d in the transverse edge 60c of flexible complex 50.

Therefore, the invention provides the different embodiment of driver, it reduces or eliminates the common issue with that the normal miniature driver is run into.The manufacturing that comprises the driver of the some or all of embodiment of the present invention can utilize usually as above-mentioned U.S. Patent No. 6,236,491 described conventional microphotolithographic techniques to be carried out.But, below in detail the exemplary details that is applicable to manufacturing process of the present invention will be described in detail.

With reference to accompanying drawing, substrate 10 defines the plane surface 12 that can construct the electrostatic MEMS device on it.In certain embodiments, substrate comprises silicon wafer because the through-silicon substrate etch the high aspect ratio hole ability be state-of-the-art, but also can use any suitable backing material with plane surface.Other semiconductor, glass, plastics or other material can be used as substrate 10.In order to form deflection structure, such as deflection piece 590, deposit and patterned metal layer are such as the chromium layer.The chromium layer also can be used for reinforcement, such as hole cap 310.Chromium is preferred, because it can not be used to limit and run through for example oxygen RIE step institute etching of the valve opening 320 of polyimide.In addition, chromium provides good adhesion between polyimide and silicon, and the common wet etchant that can not be used to remove releasing layer is corroded.The deposit of chromium can be undertaken and utilize lifting away from photoetching and coming composition by evaporation.

In some embodiments of the invention, insulation course 14 covers the plane surface of substrate 10 and electrical isolation is provided.In certain embodiments, insulation course 14 comprises the polymkeric substance based on non-oxidized substance, such as polyimide.In certain embodiments, if in the process of removing releasing layer, used some acid, so just can not use insulator based on oxide.If release layer materials and compatible acid or etchant are used to remove releasing layer, can use other insulator so, even based on the insulator of oxide.For example, if use the etchant that does not comprise hydrofluorite, silicon dioxide can be used as insulation course so.Insulation course forms on the plane surface of micro electronmechanical substrate by the deposition of materials that will be fit to.Polyimide can utilize the spin coating proceeding deposit, and passes through etching-film in oxygen RIE plasma and composition.Perhaps, can deposit and by the UV exposure polyimide material of composition Photoimageable.

In some embodiments of the invention, underlayer electrode 20 is arranged as the layer of the lip-deep general planar that is attached to following insulation course 14.In certain embodiments, underlayer electrode 20 comprises the gold layer on the end face that is deposited on insulation course 14.Can be on underlayer electrode 20 thin layer of deposit chromium so that can adhere to substrate better.Perhaps, also can use other metal or conductive material, operation is corroded as long as these materials can not be released layer processing.Cr and Au film can come deposit and utilization to lift away from photoetching technique by evaporation and come composition.The surface area of underlayer electrode 20 and shape can change according to the needs of the electrostatic force that forms expectation.

In some embodiments of the invention, can be on underlayer electrode 20 deposit second insulation course 30, with electrically insulating substrate's hearth electrode 20 and prevent and flexible electrode 40 short circuits.Second insulation course can be used as the dielectric layer with predetermined thickness between underlayer electrode 20 and flexible complex 50 and provides.In certain embodiments, second insulation course 30 comprises polyimide, can tolerate other inorganic dielectric insulator or polymkeric substance that releasing layer is handled but also can use.Second insulation course 30 can have the surface 32 of general planar.

Releasing layer is used in the present invention from for example superstructure of fixed complex 130 structure flexible complex 50.Releasing layer 34 at first is deposited on the center section 80 and the plane surface 32 in the zone below the end portion 100 of the flexible complex 50 that covers above.Releasing layer only puts on flexible complex and is not attached in the zone below following plane surface that part of.

In certain embodiments, releasing layer be included in can be etched when applying acid oxide or other material that is fit to.Releasing layer also can be near the center section 80 of flexible complex 50 deposit or be etched to the thickness of attenuate, reducing resulting slit 120 when releasing layer is etched, thereby form the stepped appearance surface.

After deposited capping layer, the miniature manufacturing acid etching technology by standard removes releasing layer usually, such as hydrofluoric acid etch.After removing releasing layer, the centre of flexible complex 50 and end portion are separated with following plane surface 32, form air gap betwixt.

In certain embodiments, releasing layer is the SiO by the PECVD deposit ₂With the releasing layer composition, and utilize wet HF or other acid etching or RIE etching to dissolve SiO with the photoresist mask layer ₂The processing that anchor (anchor) around the periphery of flexible complex 50 or groove place form the stepped appearance surface is undertaken by photoresist mask layer and wet HF or other acidity or RIE etching similarly.

The layer of flexible complex 50 covers plane surface 32 usually, and also covers releasing layer before removing releasing layer.These layers are vertically arranged and are illustrated, and described part is flatly arranged along flexible complex.Can construct these layers that comprise flexible complex 50 with known integrated circuit fabrication process.The polymer film 60 of ground floor puts on the exposed region of releasing layer and plane surface 32.Can be with polyimide as the polymer film of ground floor, comprise with releasing layer and handle compatible mutually polymkeric substance or other fexible film of inorganic material but also can use.At least, two layers can constitute flexible complex 50: the polymer film 60 of ground floor and the flexible electrode 40 of the second layer.Perhaps, minimumly two-layerly can comprise the flexible electrode 40 of ground floor and the polymer film 62 of the second layer.Flexible complex 50 can comprise all these three layers.

Flexible electrode 40 deposits with one deck flexible conducting material cover the polymer film 60 of ground floor.But in certain embodiments, flexible electrode 40 comprises gold, but also can use other can tolerate acid flexible conductor, such as conductive polymer membrane.The surface area of flexible electrode 40 or structure can change according to the needs of the electrostatic force of form wishing or change as the function apart from the distance of deformation point 105.

In certain embodiments of the present invention, second layer flexible polymeric film 62 can put on the flexible electrode layer 40.Perhaps, can be on flexible electrode layer deposit skim chromium so that can be adhered to the layered polymer film better.No matter when use the gold layer,, then can apply chromium if improve gold and the adhesion needs that close on material.Usually, polymer film is flexible, and has the thermal expansivity different with electrode layer 40.Because electrode layer 40 (if comprised, also having biasing layer 110) expands with different ratios with the polymer film of flexible complex, the layer of high thermal expansion coefficient curls so flexible complex is just towards having more.In certain embodiments, make the biasing layer, and come the deposit polyimide with spin coating proceeding with polyimide.

Enhancement layer on the valve opening 320 can form by depositing metal film on polymeric layer 62 tops.In certain embodiments of the present invention, metal can be a gold, and has by evaporation deposit and with the chromium adhesive layer that lifts away from the technology composition.Also can use other metal or material, as long as these metals have suitable physical strength and hardness and to the chemical resistance of release etch.

After finishing flexible complex 50, next step is usually directed to run through substrate ground and forms valve opening 320.Utilization puts on the photoresist mask of substrate back, carries out deep layer silicon RIE and runs through substrate 10 with etching, and stop on insulation course 14 or the deflection piece 590.Proceed etching with oxygen RIE then, once more from back etched up to exposing releasing layer.Can come the etching releasing layer so that the flexible complex film is discharged from substrate with wet HF engraving method then.

Then can the rinsing substrate, and dry in the supercritical drying device, to avoid the static friction of flexible membrane and substrate.Then can be by applying with polymeric material or, arbitrary exposed surface being applied hydrophobic surface handle by changing the surface that exposes with plasma or chemical treatment to form hydrophobic property.Hydrophobic surface makes device to move under the situation that fluid impurity is arranged by the valve opening introducing.Hydrophobic surface is handled and has been prevented between flexible complex part and the substrate owing to fluid is deposited on the static friction that causes on the surface of exposure.

As mentioned above, electrostatic actuator has a lot of application, comprises the isolating switch, minitype actuator, electric switch, valve and the variable radio frequency capacitor that are applied as optical shutter, radio-frequency phase shifter, infrared detector.Each embodiment of the present invention can be individually or is applied to these application in combination.

An example of this application comprises the electric switch that driver of the present invention is used for having at relay excessive drives structure.In this application, a contact is located on the downside of flexible complex 50, and another contact is located on the surface of fixed complex 130.As shown in figure 11, two contacts 22 and 26 are arranged so that when making flexible membrane down to substrate, contact 22 and 26 touches switch 23 and 27 respectively.If have identical thickness around the release film between the contact and the contact, so when release film during the etched and closing of contact, the just cooperation that the contact can be done, and surface of contact do not have strong closing force, and this is only to surround the contact because of actuator electrode.By on contact area with release film attenuation (whole zone or subregion), when making flexible membrane down to substrate, the contact will at first contact, and the surround electrode zone will contact then.This just is delivered to contact area with the part closing force from exciting electrode, brings better to electrically contact and lower resistance.

Another example comprises according to the present invention the driver device in the hole (for example referring to the hole among Fig. 3,4A and the 4B) that comprises as gas or fluid valve device in fixed complex.The valve device can etch the hole with high aspect ratio and forms (for example utilizing degree of depth RIE etching silicon wafer) by running through fixed complex.Can comprise glass, quartz or plastic as other substrate of fixed complex.Except degree of depth RIE, the hole in the fixed complex also can form by chemical etching or laser drill.The static excitation of valve device makes can control fluid or gas stream, and wherein flexible complex has prevented that with respect to the sealing of fixed complex gas or fluid stream from passing hole (promptly sealing this valve).

Other application of the present invention comprises optical switch, shutter or the isolating switch that is used to regulate electromagnetic radiation.For optical switch, can regulate electromagnetic radiation by the outside reflection angle that changes on the flexible complex top surface.When electrostatic actuator flattens with respect to fixed complex by voltage is put on electrode, according to incident angle, to compare when driver curls when not applying voltage, radiation will be left electrostatic actuator with different angle reflections.This device can be used for the micromirror array of optical switch.In addition as an alternative, flexible membrane comprises light absorbing material (owing to electrode material increases or intrinsic).Like this, when the flexible membrane coverage hole, for example passing, the light in hole will be cut off.Figure 11 B is the schematic side elevation according to micromechanical actuator of the present invention, and it has constituted the optical device by the micromechanical actuator excitation.Element 325 and 325b represent light source or the fluorescence detector by optical path 320 transmission or reception light respectively.

For example in shutter or isolating switch, electromagnetic radiation can be by transparent fixed complex (wherein optical path 320 constitutes entire substrate).The wavelength of electromagnetic radiation is depended in the selection that is used as the transparent substrates of fixed complex.For example, quartz can be used for the transmission of UV or visible light, and glass can be used for visible radiation, and sapphire, ZnS, Si or Ge can be used for the IR radiation.For this application, flexible complex is flattened caused the reflection of radiation by voltage being applied to electrode, thereby the curling driver that does not apply voltage just allows radiation to pass through substrate.The array of each device or shutter or isolating switch can use with any electromagnetic radiation detector of this regulator of needs or be integrated with it, such as ccd array; The HgCdTe infrared detector; Si, the GaAs or other semiconductor photo diode that are used for UV or IR; Or uncooled thermoelectricity or microradiometer infrared detector.

Under above-mentioned instruction, a lot of modification of the present invention and variation all are possible.Therefore it should be understood that within the scope of the appended claims the present invention can put into practice with the alternate manner outside being specifically described here.

Claims

1. electrostatic actuator comprises:

The base portion that comprises first electrode;

Flexible membrane, it comprises at least two material layers of contacted different materials each other, at least one material layer comprises second electrode of isolating with first electrode electricity;

This flexible membrane comprises,

Be connected to base portion anchor portion and

Opposite with anchor portion and with the isolated free end of base portion;

The described free end of flexible membrane constitutes under electrostatic force and moves with respect to base portion; And

Described second electrode has at least by separated first and second parts of third part, and this first and second part limits together and is located near the step of described anchor portion, the most close anchor portion of described first step, and compare with shorter distance and described first electrode separation with described second portion and to open.

2. according to the driver of claim 1, wherein in flexible membrane, second electrode transition in a continuous manner strides across first and second parts.

3. according to the driver of claim 1, wherein in flexible membrane, second electrode strides across first and second parts along the length of second electrode at a step place step transition.

4. according to the driver of claim 1, also comprise:

Be arranged in the non-infiltration compound at least one among flexible membrane upper surface, flexible membrane lower surface and the base portion upper surface.

5. according to the driver of claim 1, wherein first electrode is at an end that is restricted to extend through second electrode on the direction of anchor portion.

6. according to the driver of claim 1, also comprise:

Be arranged in the reinforcement on the flexible membrane away from the anchor portion of flexible membrane.

7. according to the driver of claim 1, wherein base portion comprises substrate, is arranged in first insulation course on the substrate and is arranged in second insulation course on first electrode, and described first arrangement of electrodes is on first insulation course.

8. according to the driver of claim 1, wherein flexible membrane also comprises:

The mechanical bias member, it extends to from anchor portion on the part on the free end that is not attached to base portion, and is configured to oppress flexible membrane.

9. according to the driver of claim 1, also comprise:

First electric contact on the flexible membrane;

Second electric contact on the base portion; With

Described first and second electric contacts have formed the relative contact by the electric switch of the motion control of flexible membrane.

10. according to the driver of claim 1, also comprise:

Extend through the hole of base portion; With

Described flexible membrane has the sealing surfaces that is configured to cover described hole; With

Described flexible membrane and described base portion comprise the valve by the motion control of flexible membrane.

11. according to the driver of claim 1, wherein

Described flexible membrane comprise in light absorbing material and the light reflecting material at least one and

Flexible membrane and base portion form the optical switch by the motion-activated of flexible membrane.

12. the driver according to claim 11 also comprises:

Be configured to along the light source of the surperficial direct light of flexible piece,

Described light is reflected by the light reflecting material of flexible membrane.

13. the driver according to claim 11 also comprises:

Be configured to direct light and run through the light source of base portion,

Described light is absorbed by the light absorbing material of flexible membrane.

14. the driver according to claim 1 also comprises:

Be configured to detect the radiation detector of electromagnetic radiation;

Wherein said flexible membrane comprises the cover plate that electromagnetic radiation and radiation detector are shielded.

15. according to the driver of claim 14, wherein flexible membrane comprises a plurality of flexible membranes, and radiation detector is configured to detect electromagnetic radiation at the some place of an array.

16. according to the driver of claim 15, wherein radiation detector comprises a plurality of radiation detectors.

17. an electrostatic actuator comprises:

The base portion that comprises first electrode;

This flexible membrane comprises,

Be connected to base portion anchor portion and

Opposite with anchor portion and with the isolated free end of base portion;

The described free end of flexible membrane constitutes under electrostatic force and moves with respect to base portion; With

Be arranged in the reinforcement on the flexible membrane away from anchor portion.

18. the driver according to claim 17 also comprises:

Extend through the hole of base portion; With

This reinforcement comprises a position being arranged on the flexible membrane port lid with coverage hole when the flexible membrane contact base portion.

19. according to the driver of claim 18, wherein port lid comprises at least one among round member, rectangular elements, triangle member and the elongated member.

20. according to the driver of claim 18, wherein the scope of the ratio of port lid area and hole area is from 0.5 to 20.

21. according to the driver of claim 18, wherein the scope of the thickness of port lid is from 0.1 to 3 micron.

22. according to the driver of claim 18, wherein port lid comprises conductive material.

23. according to the driver of claim 22, wherein port lid is connected to second electrode.

24. according to the driver of claim 18, wherein port lid comprises insulating material.

25. according to the driver of claim 17, wherein reinforcement comprises at least one among round member, rectangular elements, triangle member and the elongated member.

26. the driver according to claim 17 also comprises:

Be arranged in flexible membrane upper surface, flexible membrane lower surface and the base portion upper surface non-infiltration compound at least one.

27. the driver according to claim 17 also comprises:

Be positioned at first electric contact on the flexible membrane;

Be positioned at second electric contact on the base portion; With

Described first and second electric contacts form the relative contact by the electric switch of the motion control of flexible membrane.

28. the driver according to claim 17 also comprises:

Extend through the hole of base portion; With

29. according to the driver of claim 17, wherein

30. the driver according to claim 29 also comprises:

31. the driver according to claim 29 also comprises:

Be configured to direct light and run through the light source of base portion,

32. the driver according to claim 17 also comprises:

Be configured to detect the radiation detector of electromagnetic radiation;

33. according to the driver of claim 32, wherein flexible membrane comprises that a plurality of flexible membranes and radiation detector are configured to detect electromagnetic radiation at the some place of an array.

34. an electrostatic actuator comprises:

The base portion that comprises first electrode;

This flexible membrane comprises,

Be connected to base portion anchor portion and

Opposite with anchor portion and with the isolated free end of base portion;

Extend through base portion and along the elongated hole of extending away from the direction of anchor portion.

35. the driver according to claim 34 also comprises:

Deflection piece, its be configured to make fluid stream from the hole fluid stream guide towards the free end deflection of flexible membrane.

36. according to the driver of claim 35, wherein deflection piece comprises the attached end that is connected to base portion and the movable end opposite with attached end.

37. according to the driver of claim 34, its mesopore has than it towards the bigger fluid transmission cross section of a side of anchor portion in its side towards free end.

38. according to the driver of claim 37, its mesopore comprises the triangle open mouth that narrows down gradually towards anchor portion.

39. according to the driver of claim 34, its mesopore is included in the strip hole that extends on the longitudinal length direction of flexible membrane.

40. according to the driver of claim 34, its mesopore comprises a plurality of holes, described a plurality of holes form in taper or the strip at least one jointly.

41. the driver according to claim 34 also comprises:

42. according to the driver of claim 34, wherein first electrode is at an end that is restricted to extend through second electrode on the direction of anchor portion.

43. the driver according to claim 34 also comprises:

44. according to the driver of claim 34, wherein flexible membrane also comprises:

45. the driver according to claim 34 also comprises:

Extend through the hole of base portion; With

46. an electrostatic actuator comprises:

The base portion that comprises first electrode;

This flexible membrane comprises,

Be connected to base portion anchor portion and

Opposite with anchor portion and with the isolated free end of base portion;

Described first electrode is at an end that is restricted to along second electrode from free end extend through second electrode on the direction of anchor portion.

47. according to the driver of claim 46, wherein second electrode comprises the projection of extending towards base portion from the surface of second electrode, described projection has the edge of sphering, concentrates with the electric field that reduces in the described slit.

48. according to the driver of claim 46, wherein base portion comprises substrate, is arranged in first insulation course on the substrate and is arranged in second insulation course on first electrode, described first arrangement of electrodes is on first insulation course.

49. the driver according to claim 46 also comprises:

Be arranged in the dielectric film of second electrode on the side of base portion.

50. the driver according to claim 46 also comprises:

51. the driver according to claim 46 also comprises:

52. according to the driver of claim 46, wherein flexible membrane also comprises:

53. the driver according to claim 46 also comprises:

First electric contact on the flexible membrane;

Second electric contact on the base portion; With

54. the driver according to claim 46 also comprises:

Extend through the hole of base portion; With

55. according to the driver of claim 46, wherein

56. the driver according to claim 55 also comprises:

57. the driver according to claim 55 also comprises:

Be configured to direct light and run through the light source of base portion,

58. the driver according to claim 46 also comprises:

Be configured to detect the radiation detector of electromagnetic radiation;

59. according to the driver of claim 58, wherein flexible membrane comprises a plurality of flexible membranes, and radiation detector is configured to detect electromagnetic radiation at the some place of an array.

60. according to the driver of claim 59, wherein radiation detector comprises a plurality of radiation detectors.

61. an electrostatic actuator comprises:

The base portion that comprises first electrode;

This flexible membrane comprises,

Be connected to base portion anchor portion and

Opposite with anchor portion and with the isolated free end of base portion;

Be configured to provide periphery that is communicated with or side cutout with flexible membrane inside.

62. according to the driver of claim 61, wherein otch comprises the projection of flexible membrane on the lower surface of base portion, described projection is extended towards base portion.

63. according to the driver of claim 62, wherein projection comprises the fluid delivery channel of extending towards the flexible membrane core.

64. according to the driver of claim 62, wherein otch comprises the wave-like on the flexible membrane periphery edge.

65. according to the driver of claim 61, wherein otch comprises the wave-like on the flexible membrane periphery edge.

66. the driver according to claim 61 also comprises:

67. according to the driver of claim 61, wherein first electrode is at an end that is restricted to extend through second electrode on the direction of anchor portion.

68. the driver according to claim 61 also comprises:

69. according to the driver of claim 61, wherein flexible membrane also comprises:

70. the driver according to claim 61 also comprises:

71. driver according to claim 61, wherein said second electrode comprises at least by separated first and second parts of third part, and this first and second part limits together and is located near the step of described anchor portion, the most close anchor portion of described first step, and compare with shorter distance and described first electrode separation with described second portion and to open.

72. the driver according to claim 61 also comprises:

First electric contact on the flexible membrane;

Second electric contact on the base portion; With

Described first and second electric contacts comprise the electric switch by the motion control of flexible membrane.

73. the driver according to claim 61 also comprises:

Extend through the hole of base portion; With

Sealing surfaces at least one of flexible membrane and base portion; With

74. according to the driver of claim 61, wherein

75. the driver according to claim 74 also comprises:

76. the driver according to claim 74 also comprises:

Be configured to direct light and run through the light source of base portion,

77. the driver according to claim 61 also comprises:

Be configured to detect the radiation detector of electromagnetic radiation;

78. according to the driver of claim 77, wherein flexible membrane comprises a plurality of flexible membranes, and radiation detector is configured to detect electromagnetic radiation at the some place of an array.

79. according to the driver of claim 78, wherein radiation detector comprises a plurality of radiation detectors.

80. an electrostatic actuator comprises:

The base portion that comprises first electrode;

Flexible membrane, it comprises at least two contacted each other material layers, at least one material layer comprises second electrode, and described second electrode and the isolation of first electrode electricity;

Flexible membrane comprises,

Anchor portion, flexible membrane be connected at the anchor portion place base portion and

Opposite with anchor portion and with the free end in the spaced apart slit of base portion;

81. 0 driver according to Claim 8 also comprises:

82. 0 driver according to Claim 8, wherein base portion comprises substrate, is arranged in first insulation course on the substrate and is arranged in second insulation course on first electrode, and described first arrangement of electrodes is on first insulation course.

83. 0 driver according to Claim 8, wherein flexible membrane also comprises:

84. 0 driver according to Claim 8 also comprises:

First electric contact on the flexible membrane;

Second electric contact on the base portion; With

85. 0 driver according to Claim 8 also comprises:

Extend through the hole of base portion; With

Sealing surfaces in flexible membrane and the base portion at least one; With

86. 0 driver according to Claim 8, wherein

87. 6 driver according to Claim 8 also comprises:

88. 6 driver according to Claim 8 also comprises:

Be configured to direct light and run through the light source of base portion,

89. 0 driver according to Claim 8 also comprises:

Be configured to detect the radiation detector of electromagnetic radiation;

90. 9 driver according to Claim 8, wherein flexible membrane comprises a plurality of flexible membranes, and radiation detector is configured to detect electromagnetic radiation at the some place of an array.

91. according to the driver of claim 90, wherein radiation detector comprises a plurality of radiation detectors.