Information
-
Patent Grant
-
6360539
-
Patent Number
6,360,539
-
Date Filed
Wednesday, April 5, 200024 years ago
-
Date Issued
Tuesday, March 26, 200222 years ago
-
Inventors
-
Original Assignees
-
Examiners
Agents
- Myers Bigel Sibley & Sajovec
-
CPC
-
US Classifications
Field of Search
US
- 060 527
- 060 528
- 310 306
- 310 307
- 310 309
-
International Classifications
-
Abstract
Microelectromechanical actuators include a substrate, spaced apart supports on the substrate and a thermal arched beam that extends between the spaced apart supports and that further arches upon heating thereof, for movement along the substrate. One or more driven arched beams are coupled to the thermal arched beam. The end portions of the driven arched beams move relative to one another to change the arching of the driven arched beams in response to the further arching of the thermal arched beam, for movement of the driven arched beams. A driven arched beam also includes an actuated element at an intermediate portion thereof between the end portions, wherein a respective actuated element is mechanically coupled to the associated driven arched beam for movement therewith, and is mechanically decoupled from the remaining driven arched beams for movement independent thereof.
Description
FIELD OF THE INVENTION
This invention relates to microelectromechanical systems (MEMS), and more specifically to MEMS actuators.
BACKGROUND OF THE INVENTION
Microelectromechanical systems (MEMS) have been developed as alternatives to conventional electromechanical devices, such as relays, actuators, valves and sensors. MEMS devices are potentially low-cost devices, due to the use of microelectronic fabrication techniques. New functionality also may be provided, because MEMS devices can be much smaller than conventional electromechanical devices.
Many applications of MEMS technology use MEMS actuators. These actuators may use one or more beams that are fixed at one or both ends. These actuators may be actuated electrostatically, magnetically, thermally and/or using other forms of energy.
A major breakthrough in MEMS actuators is described in U.S. Pat. No. 5,909,078 entitled Thermal Arched Beam Microelectromechanical Actuators to the present inventor et al., the disclosure of which is hereby incorporated herein by reference. Disclosed is a family of thermal arched beam microelectromechanical actuators that include an arched beam which extends between spaced apart supports on a microelectronic substrate. The arched beam expands upon application of heat thereto. Means are provided for applying heat to the arched beam to cause further arching of the beam as a result of thermal expansion thereof, to thereby cause displacement of the arched beam.
Unexpectedly, when used as a microelectromechanical actuator, thermal expansion of the arched beam can create relatively large displacement and relatively large forces while consuming reasonable power. A coupler can be used to mechanically couple multiple arched beams. At least one compensating arched beam also can be included which is arched in a second direction opposite to the multiple arched beams and also is mechanically coupled to the coupler. The compensating arched beams can compensate for ambient temperature or other effects to allow for self-compensating actuators and sensors. Thermal arched beams can be used to provide actuators, relays, sensors, microvalves and other MEMS devices. Thermal arched beam microelectromechanical devices and associated fabrication methods also are described in U.S. Pat. No. 5,955,817 to Dhuler et al. entitled Thermal Arched Beam Microelectromechanical Switching Array; U.S. Pat. No. 5,962,949 to Dhuler et al. entitled Microelectromechanical Positioning Apparatus; U.S. Pat. No. 5,994,816 to Dhuler et al. entitled Thermal Arched Beam Microelectromechanical Devices and Associated Fabrication Methods; and U.S. Pat. No. 6,023,121 to Dhuler et al. entitled Thermal Arched Beam Microelectromechanical Structure, the disclosures of all of which are hereby incorporated herein by reference in their entirety.
As MEMS actuators continue to proliferate and to be used in more applications and environments, it would be desirable to allow the displacement and/or force of MEMS actuators to be controlled over wider ranges. Unfortunately, due to the scale of MEMS actuators, only a limited range of displacement and/or force may be obtainable.
A publication entitled Bent-Beam Electro-Thermal Actuators for High Force Applications by Que et al., IEEE MEMS '99 Proceedings, pp. 31-36, describes in-plane microactuators fabricated by standard microsensor materials and processes that can generate forces up to about a milli-newton. They operate by leveraging the deformations produced by localized thermal stresses. It is also shown that cascaded devices can offer a four times improvement in displacement.
Notwithstanding these improvements, there continues to be a need for MEMS actuators that can provide wider ranges of displacement and/or force for various actuator applications.
SUMMARY OF THE INVENTION
Microelectromechanical actuators according to embodiments of the invention include a substrate, spaced apart supports on the substrate and a thermal arched beam that extends between the spaced apart supports and that further arches upon heating thereof, for movement along the substrate. A plurality of driven arched beams are coupled to the thermal arched beam. The end portions of the respective driven arched beams move relative to one another to change the arching of the respective driven arched beams in response to the further arching of the thermal arched beam, for movement of the driven arched beams. A respective driven arched beam also includes a respective actuated element at an intermediate portion thereof between the end portions, wherein a respective actuated element is mechanically coupled to the associated driven arched beam for movement therewith, and is mechanically decoupled from the remaining driven arched beams for movement independent thereof. By allowing independent movement of the actuated elements, a variety of actuator applications may be provided wherein it is desired to actuate multiple elements in the same or different directions.
For example, in first embodiments, the plurality of driven arched beams comprise first and second driven arched beams that extend parallel to one another, such that the actuated elements that are mechanically coupled to the first and second driven arched beams move in a same direction by the further arching of the thermal arched beam. In other embodiments, the first and second arched beams arch away from each other, such that the actuated elements that are coupled to the first and second driven arched beams move in opposite directions by the further arching of the thermal arched beam. In yet other embodiments, the first and second driven arched beams arch toward one another, such that the actuated elements that are mechanically coupled to the first and second driven arched beams move in opposite directions by the further arching of the thermal arched beam.
In other embodiments, the respective end portions are squeezed together by the further arching of the thermal arched beam, to thereby increase arching of the driven arched beam. In alternate embodiments, the end portions are pulled apart by the further arching of the thermal arched beam, to thereby decrease arching of the driven arched beams.
In yet other embodiments, the thermal arched beam includes an intermediate portion between the end portions, and the driven arched beams include intermediate portions between the respective end portions thereof. The intermediate portions of the thermal arched beams are coupled to one of the end portions of the driven arched beams. In first embodiments, the intermediate portion of a second thermal arched beam is coupled to the other of the end portions of the driven arched beams. An H-shaped microelectromechanical actuator thereby is formed, wherein each leg of the H comprises a thermally activated arched beam, and the cross-members of the H comprises mechanically activated driven arched beams. In second embodiments, an anchor is provided that anchors the other end portions of the driven arched beams to the substrate. Thus, only one end of the driven arched beams is driven by a thermal arched beam actuator. These embodiments thereby form microelectromechanical actuators having a T-shape, wherein the cross-member of the T comprises a thermally activated arched beam and wherein the leg of the T comprises mechanically activated arched beams.
In other embodiments of microelectromechanical actuators according to the present invention, the thermal arched beam extends between the spaced apart supports along a first direction on the substrate, and further arches upon heating thereof, for movement along the substrate in a second direction that is orthogonal to the first direction. The driven arched beams extend along the substrate in the second direction and the arching of the driven arched beams is changed in the first direction by the further arching of the thermal arched beam for movement along a substrate in the first direction.
In yet other embodiments, second spaced apart supports are provided on the substrate, and a second thermal arched beam is provided that extends between the second spaced apart supports and that further arches upon heating thereof for movement along the substrate. The driven arched beams are coupled to the first and second thermal arched beams, such that the arching of the driven arched beams is changed by the further arching of the first and second thermal arched beams. More preferably, the intermediate portion of the first thermal arched beam is coupled to one end portion of the respective driven arched beams, and the intermediate portion of the second thermal arched beam is coupled to the other end portion of the respective driven arched beams.
In still other embodiments, the first and second thermal arched beams extend between the respective first and second spaced apart supports along a first direction on the substrate, and further arch upon application of heat thereto, for movement along the substrate in a second direction that is orthogonal to the first direction. The driven arched beams extend along the substrate in the second direction, and the arching of the driven arched beams are changed in the first direction by the further arching of at least one of the thermal arched beams for movement along a substrate in the first direction. In alternative embodiments, the first and second thermal arched beams extend between the respective first and second spaced apart supports along a first direction on the substrate, and further arch upon application of heat thereto, for movement along the substrate in respective opposite directions that are orthogonal to the first direction. The driven arched beams extend along the substrate along the second opposite directions, and the arching of the driven arched beams are changed in the first direction by the further arching of the thermal arched beams, for movement along the substrate in the first direction.
In other alternative embodiments of the present invention, additional mechanical advantage may be provided by coupling the plurality of driven arched beams to other driven arched beams, to provide cascaded devices. In particular embodiments, a second thermal arched beam is provided on the substrate that extends between second spaced apart supports and that further arches upon heating thereof for movement along the substrate. A first driven arched beam is coupled to the first thermal arched beam, wherein the end portions of the first driven arched beam move relative to one another to change the arching of the first driven arched beam in response to the further arching of the first thermal arched beam, for movement of the first driven arched beam along the substrate. A second driven arched beam is coupled to the second thermal arched beam, wherein the end portions of the second driven arched beam move relative to one another to change the arching of the second driven arched beam in response to the further arching of the second thermal arched beam, for movement of the second driven arched beam along the substrate. The plurality of driven arched beams are coupled to the first and second driven arched beams.
In all of the above-described embodiments, an actuator other than a thermal arched beam actuator also may be used. The actuator includes a driver beam that moves along the substrate upon actuation thereof. Multiple actuators also may be used.
Other embodiments of the present invention use at least one driven arched beam that is coupled to at least one thermal arched and that is arched in a direction that is nonparallel to the substrate. The driven arched beam includes end portions that move relative to one another to change the arching thereof in the direction that is nonparallel to the substrate in response to the further arching of the thermal arched beam, for movement of the driven arched beam toward or away from the substrate. As was described above, the end portions may be squeezed together or pulled apart. In other embodiments, the driven arched beam is arched in a direction that is orthogonal to the substrate, the arching of which is changed in the direction that is orthogonal to the substrate by the further arching of the thermal arched beam for movement orthogonal to the substrate. Out-of-plane actuators thereby may be provided. Other embodiments may provide H-shaped actuators, T-shaped actuators, cascaded actuators and/or multiple driven arched beams that are arched in a direction that is nonparallel to the substrate. In all of these embodiments, actuators other than thermal arched beam actuators that include a driver beam that moves parallel to the substrate upon actuation thereof also may be used.
In yet other embodiments according to the present invention, the intermediate portion of the thermal arched beam is coupled to the intermediate portion of the driven arched beam. First and second fixed supports also may be provided on the substrate, such that the end portions of the driven arched beam are driven against the respective fixed supports and slide along the fixed supports in response to the further arching of the thermal arched beam. Reduced displacement at higher forces may be provided thereby.
In all of the above-described embodiments, reference to a single beam also shall include multiple beams. Moreover, in all of the above-described embodiments, the microelectromechanical actuator may be combined with a relay contact, an optical attenuator, a variable circuit element, a valve, a circuit breaker and/or other elements for actuation thereby. For example, the thermal arched beam may further arch upon heating thereof by ambient heat of an ambient environment in which the microelectromechanical actuator is present, to thereby provide a thermostat. Variable optical attenuator embodiments also may be provided wherein the actuated element selectively attenuates optical radiation between ends of optical fibers that run along the substrate or through the substrate, in response to actuation of one or more thermal arched beams. In all of the above-described embodiments, a trench also may be provided in the substrate beneath at least one of the driven arched beams, to reduce stiction between the at least one driven arched beam and the substrate.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1A-9B
and
11
A-
11
B are top views of alternative embodiments of microelectromechanical actuators including driven arched beams for mechanical advantage according to the present invention.
FIGS. 10A-10C
are cross-sectional views of alternate embodiments of microelectromechanical actuators of
FIG. 9A
, taken along line
10
-
10
′ thereof.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
The present invention now will be described more fully hereinafter with reference to the accompanying drawings, in which preferred embodiments of the invention are shown. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. In the drawings, the thickness of layers and regions are exaggerated for clarity. Like numbers refer to like elements throughout. It will be understood that when an element such as a layer, region or substrate is referred to as being “on”, “connected to” or “coupled to” another element, it can be directly on, directly connected to or directly coupled to the other element, or intervening elements also may be present. In contrast, when an element is referred to as being “directly on”, “directly connected to” or “directly coupled to” another element, there are no intervening elements present.
Many of the embodiments that are described in detail below, employ thermal arched beam (TAB) actuators. The design and operation of TAB actuators are described in the above-cited U.S. Pat. Nos. 5,909,078, 5,962,949, 5,994,816, 5,995,817 and 6,023,121, the disclosures of all of which are hereby incorporated by reference herein in their entirety, and therefore need not be described in detail herein. However, it will be understood by those having skill in the art that, TABs may be heated by internal and/or external heaters that are coupled to the TAB and/or to the substrate. Moreover, one or more TAB beams may be coupled together and may be supported by one or more pairs of supports. Accordingly, all references to actuation of a TAB actuator shall be construed to cover any thermal actuation technique, all references to thermal arched beams shall be construed as covering one or more thermal arched beams, and all references to a support shall be construed to cover one or more supports that support one or more thermal arched beams.
Finally, in the drawings, fixed supports or anchors are indicated by cross-hatching, whereas movable structures are indicated by solid black. An indication of relative displacement ranges also is provided by using thin arrows for relatively small displacements and thick arrows for relatively large displacements. It also will be understood that these embodiments of microelectromechanical actuators are integrated on an underlying substrate, preferably a microelectronic substrate such as a silicon semiconductor substrate.
Referring now to
FIG. 1A
, embodiments of microelectromechanical actuators according to the present invention are shown. These microelectromechanical actuators may be referred to as “H-TAB” actuators, due to the H-shaped body thereof and the use of thermal arched beams. As shown in
FIG. 1A
, the H-shaped body includes a pair of opposing legs, each of which comprises one or more thermal arched beams
110
and
120
, and a cross-member comprising a plurality of independently moving mechanically activated arched beams
150
a
and
150
b.
More specifically, referring to
FIG. 1A
, these embodiments of microelectromechanical actuators include a substrate
100
, a first pair of spaced apart supports
130
a
and
130
b
on the substrate
100
, at least one first thermal arched beam
110
that extends between the spaced apart supports
130
a
and
130
b
and that further arches upon application of heat thereto for movement along the substrate in a first direction shown by displacement arrow
180
a.
A second pair of spaced apart supports
140
a
and
140
b
are provided, and at least one second thermal arched beam
120
extends between the second spaced apart supports
140
a
and
140
b,
and further arches in a second direction that is opposite the first direction, shown by displacement arrow
180
b,
upon application of heat thereto for movement along the substrate
100
. A plurality of driven arched beams, here two driven arched beams
150
a
and
150
b,
are coupled to the first and second thermal arched beams
110
and
120
. In particular, the respective end portions of the driven arched beams
150
a
and
150
b
are coupled to a respective intermediate portion of a respective thermal arched beam
110
and
120
, for example using respective couplers
160
a
and
160
b.
A respective driven arched beam
150
a
and
150
b
also includes a respective actuated element
170
a
and
170
b
at an intermediate portion thereof between the end portions. A respective actuated element
170
a
and
170
b
is mechanically coupled to the associated driven arched beam
150
a
and
150
b,
respectively, for movement therewith. A respective actuated element
170
a
and
170
b
is mechanically decoupled from the remaining driven arched beams, for movement independent thereof.
Thus, as shown in
FIG. 1A
, upon heating of either or both of the thermal arched beam(s)
110
and
120
, the end portions of the driven arched beam(s)
150
a
and
150
b
are squeezed together, to thereby increase arching of the driven arched beams. A relatively small amount of displacement in the first or second opposite directions shown by displacement arrows
180
a
and/or
180
b
respectively, can cause a relatively large movement of the actuated elements
170
a
and
170
b
in third opposite directions shown by respective displacement arrows
190
a
and
190
b,
that are orthogonal to the first or second directions shown by displacement arrows
180
a
and
180
b.
A mechanical advantage thereby may be obtained, and a wider range of displacements may be provided.
As also shown in
FIG. 1A
, a trench
105
optionally may be provided in the substrate
100
beneath at least one of the driven arched beams
150
a
and
150
b.
The trench can reduce stiction between the at least one driven arched beam and the substrate. A trench also may be provided beneath the thermal arched beam(s)
180
a
and/or
180
b
to reduce stiction and/or for thermal isolation. The optional trench
105
also is shown in FIG.
16
. Although it also may be included in the other embodiments described below, it is not illustrated to simplify the drawings.
Still referring to
FIG. 1A
, in the H-TAB geometry, the side TAB actuators
110
and
120
, which are oriented to actuate toward each other, can provide sufficient force, upon heating, to compress the center arched beam(s)
150
, and cause significant deflection of the actuated elements
170
attached to the center beams. Thus, the device may be described as a mechanism for changing mechanical advantage. In particular, the relatively large force and small displacement actuation of the side actuators
110
/
120
is converted to a relatively low force and relatively large displacement actuation in the center beam
150
. Displacement of 100 μm may be achieved with applied power less than 0.5 watts in silicon-based versions of embodiments of these actuators.
FIG. 1B
illustrates other embodiments wherein only one end portion of the respective driven arched beams are driven by a thermal arched beam(s). Thus, T-TAB geometries are provided, wherein the leg of the T-shaped body comprises a plurality of mechanically activated arched beams
150
a
and
150
b,
and the cross-member of the T-shaped body comprises at least one thermal arched beam
110
. More specifically, the thermal arched beam(s)
110
extend on a substrate
100
between spaced apart supports
130
a
and
130
b,
for movement along a direction shown by displacement arrow
180
a,
upon thermal actuation thereof. The intermediate portion(s) of the thermal arched beams
110
are coupled to an end portion of the driven arched beams
150
a
and
150
b,
for example using a coupler
160
a.
The other end(s) of the driven arched beams
150
a
and
150
b
are fixedly anchored by at least one anchor
140
. Multiple driven arched beams
150
a
and
150
b
include actuated elements
170
a
and
170
b
respectively. As shown, the actuated elements
170
a
and
170
b
move in a displacement direction shown by arrows
190
a
and
190
b,
respectively, upon movement of the intermediate portion of the thermal arched beams
110
in a displacement direction shown by arrow
180
a.
A mechanical advantage may be obtained as shown by displacement arrows
190
a
and
190
b.
The embodiments of
FIG. 1B
may be regarded as single-side versions of the H-TAB actuator shown in
FIG. 1A
, and may referred to as a T-TAB. The T-TAB can work similarly to the H-TAB, but may have different power/displacement performance characteristics. The device also may have a smaller footprint than an H-TAB of FIG.
1
A. An application of
FIGS. 1A and 1B
can cause the two actuated elements
170
a
and
170
b
that are coupled to the respective driven beams
150
a
and
150
b,
to actuate toward one another and contact one another, thereby providing a switch. Many other applications may be envisioned.
FIG. 2A
illustrates alternative embodiments of microelectromechanical actuators wherein the first and second driven arched beams
250
a
and
250
b
further arch away from one another in opposite directions
290
a
and
290
b,
to cause actuated elements
270
a
and
270
b
to move away from one another, in response to actuation of first and second thermal arched beams
210
and
220
that extend between spaced apart supports
230
a,
230
b
and
240
a,
240
b
on a substrate
200
. The thermal arched beams
210
and
220
actuate toward each other in the directions indicated by displacement arrows
280
a
and
280
b.
FIG. 2B
illustrates analogous embodiments wherein at least one thermal arched beam
210
is used to couple to one end of the driven arched beams
250
a
and
250
b.
The other end of driven arched beams
250
a
and
250
b
is fixed by a fixed anchor
240
.
FIG. 3A
illustrates other embodiments wherein the first and second driven arched beams
350
a
and
350
b
extend parallel to one another between the first thermal arched beam(s)
310
and the second thermal arched beam(s)
320
that extend between pairs of spaced apart supports
330
a,
330
b
and
340
a,
340
b
on a substrate
300
. Thus, in response to actuation of the first and second thermal arched beams
310
and
320
in the first and second opposite directions shown by displacement arrows
380
a
and
380
b,
the first and second driven arched beams both actuate in the same direction indicated by displacement arrows
390
a
and
390
b.
The actuated elements
370
a
and
370
b
move relative to the substrate, but not relative to one another when the driven arched beams are the same size and scope. Embodiments of
FIG. 3A
can be used for parallel contacts such as parallel current pads in microrelay or other applications. Many other applications can be envisioned. Multiple actuated elements may have many applications in optical shutter and/or electrical relay technology.
FIG. 3B
illustrates embodiments that are similar to
FIG. 3A
, except that the first and second driven arched beams
350
a
and
350
b
are driven only at one end and are maintained fixed at the other end by a fixed anchor
340
.
Referring now to
FIG. 4A
, other alternate embodiments of microelectromechanical actuators according to the present invention are shown.
FIG. 4A
may be contrasted with
FIGS. 1A-3A
, because the end portions of the driven arched beams are pulled apart by further arching of the thermal arched beam(s), to thereby decrease arching of the driven arched beams. In particular, as shown in
FIG. 4A
, first and second thermal arched beam(s)
410
and
420
respectively, arch in opposite directions shown by displacement arrows
480
a
and
480
b
and extend between first and second pairs of spaced apart supports
430
a,
430
b
and
440
a,
440
b
on a substrate
400
. Accordingly, activation of the thermal arched beams
410
and
420
causes the thermal arched beams to further arch in the opposite directions indicated by displacement arrows
480
a
and
480
b,
away from each other. This causes the arching in the driven beams
450
a
and
450
b
to decrease, thereby displacing actuated elements
470
a
and
470
b
in the direction shown by displacement arrows
490
a
and
490
b.
It will be understood that
FIG. 4A
illustrates embodiments wherein two driven arched beams
450
a
and
450
b
that extend parallel to one another in a manner similar to FIG.
3
A. However, the driven arched beams
450
a
and
450
b
may arch toward one another in a manner similar to
FIG. 1A
or away from each other in a manner similar to FIG.
2
A.
FIG. 4B
illustrates similar T-TAB actuators, except that the driven arched beams
450
a
and
450
b
are driven at one end and are maintained fixed at the other end by an anchor
440
. It will be understood that, similar to
FIG. 4A
, embodiments of driven arched beams analogous to
FIGS. 1B-3B
also may be provided.
FIG. 5
illustrates other embodiments of actuators of the present invention, wherein two side TAB actuators are arranged to actuate in the same direction. Thus, at least one first thermal arched beam
510
extends between spaced apart supports
530
a
and
530
b
on a substrate
500
, and further arches in a first direction
580
a,
shown as the left in
FIG. 5
upon application of heat thereto. At least one second thermal arched beam
520
extends between second spaced apart supports
540
a
and
540
b
on the substrate
500
, and further arches in the first direction shown by displacement arrow
580
b,
also to the left in FIG.
5
. First and second driven arched beams
550
a
and
550
b
extend between the first and second thermal arched beams
510
and
520
. As shown in
FIG. 5
, the driven arched beams may be coupled together by a single actuated element
570
.
Embodiments of
FIG. 5
can have many applications. For example, the first (left side) thermal arched beam(s)
510
can be used independently to actuate the driven beam in the direction shown by displacement arrow
590
b,
downward in FIG.
5
. Moreover, the second (right side) thermal arched beam(s)
520
may be used to independently actuate the first and second driven beams in a displacement direction
590
a
that is opposite direction
590
b,
shown as upward in FIG.
5
. Thus, a bidirectional actuator may be provided. Other applications can exploit the fact that when both the first and second thermal arched beam(s)
510
and
520
are activated, the center beam(s) does not actuate significantly in the direction
590
a
or
590
b
(although there may be some translation in the direction
580
a
). This describes an “EXCLUSIVE OR” type of logic behavior, in that the actuated element
570
only will move in the actuation direction when actuated by the first thermal arched beam(s)
510
or the second thermal arched beam(s)
520
, but not both. A form of electromechanical logic gate technology based on arched beam arrays may thereby be provided. Such logic mechanisms may have advantages over traditional electronic logic circuits. It also will be understood that in the embodiment of
FIGS. 1A
,
2
A,
3
A and
4
A, only one of the thermal arched beam(s) may be driven, or other beams may be driven simultaneously.
Alternate embodiments of
FIG. 5
can provide first and second driven arched beams
550
a
and
550
b
that are not coupled to one another, that extend toward each other and/or extend away from each other, as was described in earlier embodiments. These configurations of driven arched beams can provide more complicated logic functions or other applications.
FIGS. 6A and 6B
illustrate yet other embodiments wherein the driven arched beams of first and second spaced apart thermal arched beam actuators are themselves coupled together by another driven arched beam(s). These cascaded configurations may be used to obtain extremely large displacements or to obtain other improved performance properties such as lower power usage.
In particular, referring to
FIG. 6A
, a first driven arched beam(s)
650
is driven at the end thereof by first and second thermal arched beams
610
and
620
that extend between spaced apart supports
630
a,
630
b
and
640
a,
640
b
on a substrate
600
. Arching of the first and second thermal arched beams
610
and
620
in the directions shown by displacement arrows
680
a
and
680
b
squeezes the ends of the driven arched beams
650
a
and
650
b
to cause displacement of the actuated elements
675
a
and
675
b
in the directions shown by displacement arrows
690
a
and
690
b.
A mirror image of this structure is provided, including third and fourth thermal arched beams
610
′ and
620
′ and a second driven arched beam(s)
650
′, with the corresponding elements indicated by prime notation. At least one third driven arched beam
675
is coupled between the first and second driven arched beams
650
and
650
′. More specifically, the ends of the third driven arched beam(s)
675
are coupled between the intermediate portions of the first and second thermal arched beam(s)
650
and
650
′. Upon actuation of the first, second, third and fourth thermal arched beams
610
,
620
,
610
′ and
620
′, the ends of the third driven arched beam(s)
650
a
and
650
b
may be squeezed by a large amount due to the displacement amplification provided by the first and second driven arched beams
650
and
650
′, to thereby provide a large displacement of contact
670
in the direction shown by arrow
695
. It will be understood that each of the actuators of
FIG. 6A
may be embodied using any of the previously described embodiments and the third driven arched beam(s)
675
a
and
675
b
also may be embodied using any of the previously described embodiments. It also will be understood that not all of thermal arched beams
610
,
620
,
610
′ and
620
′ need be actuated simultaneously.
FIG. 6B
is similar to
FIG. 6A
, except it describes a third driven arched beam that is driven at one end only by an H-TAB actuator. The other end of the third driven arched beams
675
is fixed by an anchor
640
.
FIG. 7A
illustrates embodiments of the present invention that may be used to form a Variable Optical Attenuator (VOA) and/or an optical switch (a binary optical attenuator).
FIG. 7A
illustrates an H-TAB VOA that includes at least one first thermal arched beam
710
between first spaced apart supports
730
a
and
730
b
on a substrate
700
and at least one second thermal arched beam
720
between second spaced apart supports
740
a
and
740
b
on the substrate
700
. At least one driven arched beam
750
is coupled between the first and second thermal arched beams
710
and
720
, for example using couplers
760
a
and
760
b.
When the first and second thermal arched beams
710
and
720
displace towards one another as shown by displacement arrows
780
a
and
780
b,
the at least one driven arched beam
750
moves in the direction
790
.
In
FIG. 7A
, the two thermal arched beams
750
are shown coupled together by a coupler
770
. A paddle
775
is attached to the coupler
770
. It will be understood that the paddle
775
and the coupler
770
may form one integral structure. The paddle
775
is oriented so as to selectively cover an end of an optical fiber
778
that passes through the substrate
700
, for example orthogonal or at an oblique angle to the substrate face. Upon displacement in the direction
790
, variable or binary optical attenuation of optical radiation through the fiber
778
may be provided. Thus, VOAs with high precision, low power and/or small footprint may be provided. It also will be understood that the paddle
775
and coupler
770
may be configured such that attenuation may be provided upon displacement in a direction that is opposite the direction
790
.
FIG. 7B
illustrates embodiments of analogous T-TAB VOAs wherein a fixed support
740
is used rather than a second thermal arched beam(s).
FIGS. 8A and 8B
illustrate alternative embodiments of H-TAB VOAs and T-TAB VOAs, respectively. In these embodiments, two ends of optical fibers
878
a
and
878
b
extend along the substrate
800
and the integrated paddle/coupler
770
selectively attenuates optical radiation passing between the fiber ends
878
a
and
878
b.
It also will be understood that all the other embodiments that are described herein may be used to provide VOAs for one or more fibers.
Referring now to
FIGS. 9A and 9B
, other embodiments of H-TAB and T-TAB actuators according to the present invention as shown. In contrast with the earlier embodiments, these actuators can provide “out of plane” actuation wherein the driven beams arches in a direction that is nonparallel to the substrate. The driven beam includes end portions that move relative to one another to arch the driven beam in a direction that is nonparallel to the substrate in response to the further arching of the thermal arched beam(s) for movement of the driven beam toward or away from the substrate.
More specifically, as shown in
FIG. 9A
, first and second thermal arched beam(s)
910
and
920
are included on a substrate
900
and are supported by first and second pairs of spaced apart supports
930
a,
930
b
and
940
a,
940
b
for actuation in the displacement directions shown by displacement arrows
980
a
and
980
b.
A driven beam such as a driven arched beam
950
is coupled to the first and second thermal arched beams
910
and
920
, for example using couplers
960
a
and
960
b.
As shown in
FIG. 9A
, the driven beam
950
preferably is wider than the thermal arched beams
910
and
920
when viewed from above, so that arching along the substrate is not promoted. Moreover, as will be described below, the driven beam
950
preferably is thin in cross-section to promote arching out of the plane of the substrate as shown by displacement indicator
990
.
FIG. 9B
illustrates a similar T-TAB configuration that uses a fixed support
940
rather than a second thermal arched beam(s)
920
.
FIGS. 10A-10C
are cross-sectional views of
FIG. 9A
along line
10
-
10
′ to illustrate the arching of the driven beam
950
out of the plane of the substrate
900
.
Referring now to
FIG. 10A
, the substrate
900
includes an optional trench
905
that can reduce stiction and can provide clearance for the out of plane arched beam
950
. As can be seen from
FIG. 10A
, the driven arched beam
950
is thin in cross-section relative to the thermal arched beams
910
and
920
, so that displacement occurs in the displacement direction
990
as shown.
FIG. 10A
illustrates arching that may be provided by a continuous driven arched beam
950
. In contrast,
FIG. 10B
illustrates arching that may be provided by a stepped arched beam that includes a pair of end sections
950
a
and
950
b
and a center section
950
c
that is offset from the end sections
950
a
and
950
b.
If the center section
950
c
is offset beneath the end sections
950
a
and
950
b,
arching toward the substrate
900
may be provided.
FIG. 10C
illustrates yet another embodiment wherein the combination of the coupler
960
and a straight beam
950
′ may provide an equivalent to an arched beam by biasing the beam to arch in the displacement direction
990
as shown.
It also will be understood that multiple driven arched beams
950
may be provided that arch in the same or opposite directions as was illustrated in connection with
FIGS. 1-6
above. Moreover, out of plane variable optical attenuators similar to those which were disclosed in
FIGS. 7 and 8
also may be provided. Finally, it also will be noted that although arching is shown orthogonal to the substrate, arching may be provided at any oblique angle to the substrate.
FIG. 11A
describes other embodiments of microelectromechanical actuators according to the present invention. In these embodiments, a relatively large displacement and relatively small force of a TAB actuator is converted to a relatively large force and relatively small displacement in at least one driven arched beam. Accordingly, the mechanical advantage of the driven arched beam may be reversed compared to
FIGS. 1-10
.
More particularly, referring to
FIG. 11A
, at least one thermal arched beam
1110
extends between spaced apart supports
1130
a
and
1130
b
on a substrate
1100
. Actuation of the thermal arched beam(s)
1110
causes the intermediate portion thereof, to move in a first direction indicated by displacement arrow
1180
. The thermal arched beam(s)
1110
is coupled to an intermediate portion of a driven arched beam(s)
1150
, for example using a coupler
1160
. Accordingly, upon actuation, the end portion(s) of the driven arched beam(s)
1150
are driven against a pair of fixed supports
1192
a,
1192
b
and slide along the fixed supports
1192
a,
1192
b
in the directions shown by displacement arrows
1190
a
and
1190
b.
Microelectromechanical actuators of
FIG. 11A
may be embodied as a “shorting bar” microrelay. In these applications, the thermal arched beam(s)
1110
is used to drive contacts
1170
a
and/or
1170
b
at the ends of a driven arched beam(s)
1150
into a pair of fixed contacts
1192
a
and
1192
b,
to which signals may be applied at signal pads
1194
a,
1194
b.
The contacts
1170
a
and
1170
b
at the end of the driven arched beam(s)
1350
are driven against the rigid contacts
1192
a
and
1192
b
and then slide along the rigid contacts
1192
a
and
1192
b
along the respective directions
1190
a
and
1190
b.
Thus, the relatively large displacement of the thermal arched beam
1110
can be converted to a relatively large force at the two points of contact between the contacts
1170
a
and
1170
b
and the fixed contacts
1192
a
and
1192
b.
A mechanical stop
1196
may be used to prevent snap-through buckling of the driven arched beams.
FIG. 11B
illustrates other embodiments wherein further arching of the thermal arched beam(s)
1110
causes the ends of the driven arched beam(s)
1150
to move toward one another in directions
1190
a
′ and
1190
b
′. Like elements are indicated by prime notation. Many other embodiments may be envisioned.
There can be many uses for embodiments of microelectromechanical actuators according to the present invention. Optical applications may be envisioned, such as using an H-TAB actuator to drive variable optical attenuators and/or optical crossconnect switching devices. Electrical and/or radio frequency applications, such as using an H-TAB actuator to drive a microrelay or variable capacitor/inductor also may be provided. A thermostat may be provided wherein the thermal arched beam further arches upon heating thereof by ambient heat of an ambient environment in which the microelectromechanical actuator is present. Other applications, such as using these actuator arrays for microfluidic control or micropneumatic control, may be provided. Accordingly, one or more of the driven arched beams may be coupled to other elements, such as relay contacts, optical attenuators, variable circuit elements such as resistors and capacitors, valves and circuit breakers. Many other configurations and applications that use cascaded arched beams, both thermal and mechanical in order to change mechanical advantage also may be provided.
In the drawings and specification, there have been disclosed typical preferred embodiments of the invention and, although specific terms are employed, they are used in a generic and descriptive sense only and not for purposes of limitation, the scope of the invention being set forth in the following claims.
Claims
- 1. A microelectromechanical actuator comprising:a substrate; spaced apart supports on the substrate; a thermal arched beam that extends between the spaced apart supports and that further arches upon heating thereof for movement parallel the substrate; and a driven beam that is coupled to the thermal arched beam, the driven beam including end portions that move relative to one another to arch the driven beam in a direction that is nonparallel to the substrate in response to the further arching of the thermal arched beam, for movement of the driven beam toward or away from the substrate.
- 2. A microelectromechanical actuator according to claim 1 wherein the end portions are squeezed together by the further arching of the thermal arched beam to thereby increase arching of the driven beam.
- 3. A microelectromechanical actuator according to claim 1 wherein the end portions are pulled apart by the further arching of the thermal arched beam to thereby decrease arching of the driven beam.
- 4. A microelectromechanical actuator according to claim 1 wherein the thermal arched beam includes an intermediate portion between end portions thereof, wherein the driven beam includes an intermediate portion between the end portions thereof and wherein the intermediate portion of the thermal arched beam is coupled to one of the end portions of the driven beam.
- 5. A microelectromechanical actuator according to claim 4 further comprising an anchor that anchors the other end portion of the driven beam to the substrate.
- 6. A microelectromechanical actuator according to claim 1:wherein the driven beam arches in a direction that is orthogonal to the substrate by the further arching of the thermal arched beam for movement orthogonal to the substrate.
- 7. A microelectromechanical actuator according to claim 1 wherein the driven beam is a driven arched beam that is arched in the direction that is nonparallel to the substrate, such that the arching of the driven arched beam is changed in the direction that is nonparallel to the substrate in response to the further arching of the thermal arched beam.
- 8. A microelectromechanical actuator according to claim 1 wherein the spaced apart supports are first spaced apart supports and wherein the thermal arched beam is a first thermal arched beam, the thermal arched beam microelectromechanical actuator further comprising:second spaced apart supports on the substrate; a second thermal arched beam that extends between the second spaced apart supports and that further arches upon heating thereof for movement parallel to the substrate; and wherein the driven beam is coupled to the first and second thermal arched beams, such that the end portions thereof move relative to one another to arch the driven beam in the direction that is nonparallel to the substrate in response to the further arching of the first and second thermal arched beams.
- 9. A microelectromechanical actuator according to claim 8 wherein the first and second thermal arched beams each include an intermediate portion between end portions, wherein the driven beam includes an intermediate portion between the end portions thereof, wherein the intermediate portion of the first thermal arched beam is coupled to one end portion of the driven beam and wherein the intermediate portion of the second thermal arched beam is coupled to the other end portion of the driven beam.
- 10. A microelectromechanical actuator according to claim 1 in combination with at least one of a relay contact, an optical attenuator, a variable circuit element, a valve and a circuit breaker that is mechanically coupled to the driven arched beam for actuation thereby.
- 11. A microelectromechanical actuator according to claim 1 wherein the thermal arched beam further arches upon heating thereof by ambient heat of an ambient environment in which the microelectromechanical actuator is present, to thereby provide a thermostat.
- 12. A microelectromechanical actuator according to claim 1 wherein the driven beam is a first driven arched beam and wherein the direction that is nonparallel to the substrate is a first direction that is nonparallel to the substrate, the microelectromechanical actuator further comprising:a second driven arched beam that is coupled to the thermal arched beam and that is arched in a second direction that is nonparallel to the substrate, the second driven arched beam including end portions that move relative to one another to change the arching of the second driven arched beam in the second direction that is nonparallel to the substrate in response to the further arching of the thermal arched beam for movement of the second driven arched beam toward or away from the substrate.
- 13. A microelectromechanical actuator according to claim 12 wherein the first and second driven arched beams extend parallel to one another and nonparallel to the substrate such that the arching of the first and second driven arched beams changes in a same direction by the further arching of the thermal arched beam.
- 14. A microelectromechanical actuator according to claim 13 further comprising a coupler that mechanically couples the first and second driven arched beams.
- 15. A microelectromechanical actuator according to claim 12 wherein the first and second driven arched beams arch away from one another such that the arching of the first and second driven arched beams changes in opposite directions by the further arching of the thermal arched beam.
- 16. A microelectromechanical actuator according to claim 12 wherein the first and second driven arched beams arch toward one another such that the arching of the first and second driven arched beams changes in opposite directions by the further arching of the thermal arched beam.
- 17. A microelectromechanical actuator according to claim 1 wherein the spaced apart supports are first spaced apart supports, wherein the thermal arched beam is a first thermal arched beam and wherein the driven beam is a third driven beam, the microelectromechanical actuator further comprising:second spaced apart supports on the substrate; a second thermal arched beam that extends between the second spaced apart supports and that further arches upon heating thereof for movement parallel to the substrate; a first driven arched beam that is coupled to the first thermal arched beam, the first driven arched beam including end portions that move relative to one another to change the arching of the first driven arched beam in response to the further arching of the first thermal arched beam for movement of the second driven arched beam parallel to the substrate; and a second driven arched beam that is coupled to the second thermal arched beam, the second driven arched beam including end portions that move relative to one another to change the arching of the second driven arched beam in response to the further arching of the thermal arched beam for movement of the second driven arched beam parallel to the substrate; wherein the third driven beam is coupled to the first and second driven arched beams, the third driven beam including end portions that move relative to one another to arch the third driven beam in the direction that is nonparallel to the substrate in response to the changed arching of the first and second driven arched beams.
- 18. A microelectromechanical actuator according to claim 17 further comprising:a fourth driven beam that is coupled to the first and second driven arched beams, the fourth driven beam including end portions that move relative to one another to arch the fourth driven beam in response to the changed arching of the first and second driven arched beams.
- 19. A microelectromechanical actuator according to claim 18 wherein the third and fourth driven beams are third and fourth driven arched beams that extend parallel to one another and nonparallel to the substrate such that the arching of the third and fourth driven arched beams changes in a same direction by the further arching of the first and second thermal arched beams.
- 20. A microelectromechanical actuator according to claim 19 further comprising a coupler that mechanically couples the third and fourth driven arched beams.
- 21. A microelectromechanical actuator according to claim 18 wherein the third and fourth driven beams arch away from one another such that the arching of the third and fourth driven beams changes in opposite directions by the further arching of the first and second thermal arched beams.
- 22. A microelectromechanical actuator according to claim 18 wherein the third and fourth driven beams arch toward one another such that the arching of the third and fourth driven beams changes in opposite directions by the further arching of the first and second thermal arched beams.
- 23. A microelectromechanical actuator comprising:a substrate; an actuator on the substrate that includes a driver beam that moves parallel to the substrate upon actuation of the actuator; and a driven beam that is coupled to the driver beam, the driven beam including end portions that move relative to one another to arch the driven beam in a direction that is nonparallel to the substrate in response to the movement of the driver beam parallel to the substrate.
- 24. A microelectromechanical actuator according to claim 23 wherein the end portions are squeezed together by the movement of the driver beam to thereby increase arching of the driven beam.
- 25. A microelectromechanical actuator according to claim 23 wherein the end portions are pulled apart by the movement of the driver beam to thereby decrease arching of the driven beam.
- 26. A microelectromechanical actuator according to claim 23 wherein the driven beam includes an intermediate portion between the end portions thereof and wherein the driver beam is coupled to one of the end portions of the driven beam.
- 27. A microelectromechanical actuator according to claim 26 further comprising an anchor that anchors the other end portion of the driven beam to the substrate.
- 28. A microelectromechanical actuator according to claim 23 wherein the driven beam is a driven arched beam that is arched in the direction that is nonparallel to the substrate, such that the arching of the driven arched beam is changed in the direction that is nonparallel to the substrate in response to the movement of the driver beam.
- 29. A microelectromechanical actuator according to claim 23 wherein the actuator is a first actuator and wherein the driver beam is a first driver beam, the microelectromechanical actuator further comprising:a second actuator on the substrate that includes a second driver beam that moves parallel to the substrate upon actuation of the second actuator; and wherein the driven beam is coupled to the first and second driver beams, such that the end portions thereof move relative to one another to arch the driven beam in the direction that is nonparallel to the substrate in response to the movement of the first and second driver beams along the substrate.
- 30. A microelectromechanical actuator according to claim 29 wherein the driven beam includes an intermediate portion between the end portions thereof, wherein the first driver beam is coupled to one end portion of the driven beam and wherein the second driver beam is coupled to the other end portion of the driven beam.
- 31. A microelectromechanical actuator according to claim 23 in combination with at least one of a relay contact, an optical attenuator, a variable circuit element, a valve and a circuit breaker that is mechanically coupled to the driven arched beam for actuation thereby.
- 32. A microelectromechanical actuator according to claim 23 wherein the driven beam is a first driven arched beam and wherein the direction that is nonparallel to the substrate is a first direction that is nonparallel to the substrate, the microelectromechanical actuator further comprising:a second driven arched beam that is coupled to the driver beam and that is arched in a second direction that is nonparallel to the substrate, the second driven arched beam including end portions that move relative to one another to change the arching of the second driven arched beam in the second direction that is nonparallel to the substrate in response to the movement of the driver beam.
- 33. A microelectromechanical actuator according to claim 32 wherein the first and second driven arched beams extend parallel to one another and nonparallel to the substrate such that the arching of the first and second driven arched beams changes in a same direction by the movement of the driver beam.
- 34. A microelectromechanical actuator according to claim 33 further comprising a coupler that mechanically couples the first and second driven arched beams.
- 35. A microelectromechanical actuator according to claim 33 wherein the first and second driven arched beams arch away from one another such that the arching of the first and second driven arched beams changes in opposite directions by the movement of the driver beam.
- 36. A microelectromechanical actuator according to claim 33 wherein the first and second driven arched beams arch toward one another such that the arching of the first and second driven arched beams changes in opposite directions by the movement of the driver beam.
- 37. A microelectromechanical actuator according to claim 23 wherein the actuator is a first actuator, wherein the driver beam is a first driver beam and wherein the driven beam is a third driven beam, the microelectromechanical actuator further comprising:a second actuator on the substrate that includes a second driver beam that moves parallel to the substrate upon actuation of the second actuator; a first driven arched beam that is coupled to the first driver beam, the first driven arched beam including end portions that move relative to one another to change the arching of the first driven arched beam in response to the movement of the first driver beam parallel to the substrate; and a second driven arched beam that is coupled to the second driver beam, the second driven arched beam including end portions that move relative to one another to change the arching of the second driven arched beam in response to the movement of the second driver beam parallel to the substrate; and wherein the third driven beam is coupled to the first and second driven arched beams, the third driven beam including end portions that move relative to one another to arch the third driven beam in the direction that is nonparallel to the substrate in response to the changed arching of the first and second driven beams.
- 38. A microelectromechanical actuator according to claim 37 further comprising:a fourth driven beam that is coupled to the first and second driven arched beams, the fourth driven beam including end portions that move relative to one another to arch the fourth driven beam in response to the changed arching of the first and second driven arched beams.
- 39. A microelectromechanical actuator comprising:a substrate; first spaced apart supports on the substrate; a first thermal arched beam that extends between the first spaced apart supports and that further arches upon heating thereof for movement along the substrate in a first direction; second spaced apart supports on the substrate; a second thermal arched beam that extends between the second spaced apart supports and that further arches upon heating thereof for movement along the substrate in the first direction; and a driven arched beam including respective first and second end portions that are coupled to the respective first and second thermal arched beams such that the further arching of the first thermal arched beam squeezes the end portions together, the further arching of the second thermal arched beam pulls the end portions apart and simultaneous further arching of the first and second thermal arched beams translates the driven arched beam in the first direction without moving the end portions relative to one another.
- 40. A microelectromechanical actuator according to claim 39 wherein the first thermal arched beam includes an intermediate portion between end portions thereof, wherein the second thermal arched beam includes an intermediate portion between end portions thereof and wherein the intermediate portion of the respective first and second thermal arched beams are coupled to the respective first and second end portions of the driven arched beam.
- 41. A microelectromechanical actuator according to claim 39 in combination with at least one of a relay contact, an optical attenuator, a variable circuit element, a valve and a circuit breaker that is mechanically coupled to the driven arched beam for actuation thereby.
- 42. A microelectromechanical actuator comprising:a substrate; a first actuator on the substrate that includes a first driver beam that moves along the substrate in a first direction upon actuation of the first actuator; a second actuator on the substrate that includes a second driver beam that moves along the substrate in the first direction upon actuation of the second actuator; and a driven arched beam including respective first and second end portions that are coupled to the respective first and second driver beams such that the movement of the first driver beam squeezes the end portions together, the movement of the second driver beam pulls the end portions apart and simultaneous movement of the first and second driver beams translates the driven arched beam in the first direction without moving the end portions relative to one another.
- 43. A microelectromechanical actuator according to claim 42 in combination with at least one of a relay contact, an optical attenuator, a variable circuit element, a valve and a circuit breaker that is mechanically coupled to the driven arched beam for actuation thereby.
- 44. A microelectromechanical actuator comprising:a substrate; spaced apart supports on the substrate; a thermal arched beam that extends between the spaced apart supports and that further arches upon heating thereof for movement along the substrate; a driven arched beam that is coupled to the thermal arched beam, the driven arched beam including end portions that move relative to one another to change the arching of the driven arched beam in response to the further arching of the thermal arched beam, for movement of the driven arched beam along the substrate; and an optical attenuator that is coupled to the driven arched beam and that is arranged to move into an optical path on the substrate in response to movement of the driven arched beam along the substrate such that the optical attenuator blocks at least a portion of optical radiation in the optical path.
- 45. A microelectromechanical actuator according to claim 44 wherein the optical path is oriented along the substrate.
- 46. A microelectromechanical actuator according to claim 45 wherein the optical path comprises two optical fibers on the substrate that are oriented in end-to-end relationship, such that the optical attenuator is arranged to move between adjacent ends of the two optical fibers in response to movement of the driven arched beams along the substrate.
- 47. A microelectromechanical actuator according to claim 44 wherein the optical path is oriented orthogonal to the substrate.
- 48. A microelectromechanical actuator according to claim 47 wherein the optical path comprises an optical fiber that passes through the substrate such that an end of the optical fiber is parallel to the substrate, wherein the optical attenuator is arranged to cover at least part of the end of the optical fiber in response to movement of the driven arched beam along the substrate.
- 49. A microelectromechanical actuator according to claim 44 wherein the end portions are squeezed together by the further arching of the thermal arched beam to thereby increase arching of the driven arched beam.
- 50. A microelectromechanical actuator according to claim 44 wherein the end portions are pulled apart by the further arching of the thermal arched beam to thereby decrease arching of the driven arched beam.
- 51. A microelectromechanical actuator according to claim 44 wherein the thermal arched beam includes an intermediate portion between end portions thereof and wherein the intermediate portion of the thermal arched beam is coupled to one of the end portions of the driven arched beam.
- 52. A microelectromechanical actuator according to claim 51 further comprising an anchor that anchors the other end portion of the driven arched beam to the substrate.
- 53. A microelectromechanical actuator according to claim 44 wherein the spaced apart supports are first spaced apart supports and wherein the thermal arched beam is a first thermal arched beam, the thermal arched beam microelectromechanical actuator further comprising:second spaced apart supports on the substrate; a second thermal arched beam that extends between the second spaced apart supports and that further arches upon heating thereof for movement along the substrate; and wherein the driven arched beam is coupled to the first and second thermal arched beams, such that the end portions thereof move relative to one another to change the arching of the driven arched beam in response to the further arching of the first and second thermal arched beams.
- 54. A microelectromechanical actuator according to claim 44 wherein the spaced apart supports are first spaced apart supports and wherein the thermal arched beam is a first thermal arched beam, the microelectromechanical actuator further comprising:second spaced apart supports on the substrate; a second thermal arched beam that extends between the spaced apart supports and that further arches upon heating thereof for movement along the substrate; a second driven arched beam that is coupled to the second thermal arched beam, the second driven arched beam including end portions that move relative to one another to change the arching of the second driven arched beam in response to the further arching of the thermal arched beam for movement of the second driven arched beam along the substrate; and a third driven arched beam that is coupled to the first and second driven arched beams, the third driven arched beam including end portions that move relative to one another to change the arching of the third driven arched beam in response to the changed arching of the first and second driven arched beams; wherein the optical attenuator is coupled to the third driven arched beam and is arranged to move into the optical path on the substrate in response to movement of the third driven arched beam along the substrate.
- 55. A microelectromechanical actuator comprising:a substrate; an actuator on the substrate that includes a driver beam that moves along the substrate upon actuation of the actuator; a driven beam that is coupled to the driver beam, the driven beam including end portions that move relative to one another to arch and move the driven beam along the substrate in response to movement of the driven beam; and an optical attenuator that is coupled to the driven beam and that is arranged to move into an optical path on the substrate in response to movement of the driven beam along the substrate such that the optical attenuator blocks at least a portion of optical radiation in the optical path.
- 56. A microelectromechanical actuator according to claim 55 wherein the optical path is oriented along the substrate.
- 57. A microelectromechanical actuator according to claim 56 wherein the optical path comprises two optical fibers on the substrate that are oriented in end-to-end relationship, such that the optical attenuator is arranged to move between adjacent ends of the two optical fibers in response to movement of the driven beam along the substrate.
- 58. A microelectromechanical actuator according to claim 55 wherein the optical path is oriented orthogonal to the substrate.
- 59. A microelectromechanical actuator according to claim 55 wherein the optical path comprises an optical fiber that passes through the substrate, wherein the optical attenuator is arranged to cover at least part of the end of the optical fiber in response to movement of the driven beam along the substrate.
- 60. A microelectromechanical actuator according to claim 55 wherein the end portions are squeezed together by the further arching of the thermal arched beam to thereby increase arching of the driven beam.
- 61. A microelectromechanical actuator according to claim 55 wherein the end portion s are pulled a part by the further arching of the thermal arched beam to thereby decrease arching of the driven beam.
- 62. A microelectromechanical actuator according to claim 55 wherein the driver beam is coupled to one of the end portions of the driven beam.
- 63. A microelectromechanical actuator according to claim 62 further comprising an anchor that anchors the other end portion of the driven beam to the substrate.
- 64. A microelectromechanical actuator according to claim 55 wherein the actuator is a first actuator, wherein the driver beam is a first driver beam, the microelectromechanical actuator further comprising:a second actuator on the substrate that includes a second driver beam that moves along the substrate upon actuation of the second actuator; and wherein the driven beam is coupled to the first and second driver beams, such that the end portions thereof move relative to one another to arch the driven beam in response to the movement of the first and second driver beams.
- 65. A microelectromechanical actuator according to claim 55 wherein the actuator is a first actuator, wherein the driver beam is a first driver beam, the microelectromechanical actuator further comprising:a second actuator on the substrate that includes a second driver beam that moves along the substrate upon actuation of the second actuator; a second driven beam that is coupled to the second driver beam, the second driven beam moving along the substrate upon actuation of the second actuator; and a third driven beam that is coupled to the first and second driven beams, the third driven beam including end portions that move relative to one another to change the arching of the third driven beam in response to the movement of the first and second driven beams; wherein the optical attenuator is coupled to the third driven beam and is arranged to move into an optical path on the substrate in response to movement of the third driven arched beam along the substrate.
US Referenced Citations (7)