Patent Publication Number: US-8541926-B2

Title: Nano/micro electro-mechanical relay

Description:
GOVERNMENT INTEREST 
     The invention described herein may be manufactured, used and licensed by or for the U.S. Government. 
    
    
     FIELD OF INVENTION 
     The present disclosure relates electro-mechanical relays, particularly to electro-mechanical relays that can operate as Micro-Electro-Mechanical Systems (MEMS) technology as well as nanotechnology. 
     BACKGROUND OF THE INVENTION 
     Electro-mechanical relays were historically discrete analog switches that were used in early computers for such applications as to implement Boolean logic. Discrete electro-mechanical relays continue in common usage for certain commercial, automotive, communications, automation, power, and other applications. Inherent advantages of electro-mechanical relays include relatively low current leakage and excellent reliability of operation. 
     Transistors have largely supplanted electro-mechanical relays in such applications as computers, digital logic, and communications. Fabrication of transistors, and other such devices, relies on such solid-state semiconductor processing techniques. Conventional transistors (including, for example, NMOS, CMOS, field effect transistors, bipolar transistors, or other types) have some voltage drop across their terminals that typically result in current leakage. Such leakage can result in considerable power consumption for the transistors themselves as well as their associated circuits. Additionally, transistors have difficulty operating in harsh or radioactive environments. 
     Therefore, there is a need in the art for switching devices having limited current leakage, as well as being able to function in harsh or radioactive environments. 
     BRIEF SUMMARY OF THE INVENTION 
     Embodiments of the present invention include a nano/micro electro-mechanical relay, comprising an at least one normally open (NO) nano/micro relay switch and an at least one normally closed (NC) nano/micro relay switch. Both the NC nano/micro relay switch and the NO nano/micro relay switch operationally include at least one displaceable contact pad that can be displaced relative to at least one substrate anchored pad to substantially simultaneously switch the NC nano/micro relay switch and the NO nano/micro relay switch between their respective normal relay switch positions and their respective actuated relay switch positions. An at least one nano/micro actuator including an at least one piezoelectric stack layer being attached to an at least one elastic layer, wherein to actuate the at least one nano/micro actuator, the at least one piezoelectric stack layer contracts to deflect the at least one elastic layer. Certain embodiments of the nano/micro electro-mechanical relay can further include at least one nano/micro contact bar that when actuated by the at least one nano/micro actuator configured to simultaneously switch the NC nano/micro relay switch and the NO nano/micro relay switch between their respective normal relay switch position and their respective actuated relay switch positions. The simultaneous switching can be at least partially in response to deflection of the at least one nano/micro actuator. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  illustrates a top view of one embodiment of a nano/micro electro-mechanical relay; 
         FIG. 2  illustrates a partial cross-sectional view of one embodiment of a nano/micro electro-mechanical relay as taken through sectional lines  2 - 2  of  FIG. 1 , also shown is a dotted-line outline of a substrate that supports the nano/micro electro-mechanical relay; 
         FIG. 3  is a top view of another embodiment of a nano/micro electro-mechanical relay; 
         FIG. 4  illustrates a partial cross-sectional view of one embodiment of a nano/micro electro-mechanical relay as taken through sectional lines  4 - 4  of  FIG. 3 , also with a dotted outline of a supporting substrate structure; 
         FIG. 5  illustrates a partial cross-sectional view of one embodiment of a nano/micro electro-mechanical relay as taken through sectional lines  5 - 5  of  FIG. 3 , also with a dotted outline of a supporting substrate structure; 
         FIG. 6  is a top view of another embodiment of the nano/micro electro-mechanical relay, which is configured to include the nano/micro relay switch pair; 
         FIG. 7  shows a schematic diagram of one embodiment of a relaxation oscillator that can be fabricated using the nano/micro electro-mechanical relay; 
         FIG. 8  shows a schematic diagram of one embodiment of a dynamic latch that can be fabricated using one nano/micro electro-mechanical relay and a capacitive element; and 
         FIG. 9  shows a schematic diagram of one embodiment of a dynamic latch with a buffer that can be fabricated using one dynamic latch, as described with respect to  FIG. 8 . 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Throughout this disclosure, similar reference characters may be provided for similar elements in the different embodiments, which may perform identical or similar functions. For example, there are multiple conductive traces attached to each of the normally open (NO) relay switch and normally closed (NC) relay switch in each of the different embodiments of the relay switches illustrated in different ones of the figures. As such, each conductive trace may be provided the same reference number, though a reference letters can be appended where necessary such as  84 ,  84   a ,  84   b ,  84   c ,  84   d , etc. Within this disclosure, any description referring to one device having the reference character can refer, depending on context, to other devices sharing that reference character. 
       FIG. 1  illustrates a top view of one embodiment of a nano/micro electro-mechanical relay  60 . This disclosure provides a number of embodiments of the nano/micro electro-mechanical relays  60  as described in a general with respect to  FIG. 1 . Certain embodiments can be fabricated utilizing such solid-state techniques as ultra-large scale integration and micro-electro-mechanical system (hereinafter referred to as “MEMS”), and also may be configured to operate within the nanoscale. Such minute devices in many cases, such as the present instance, can be analogized, modeled, or scaled to operate predictably largely based upon a well-developed understanding of discrete electro-mechanical devices such as relays. MEMS devices are becoming better known for such applications as relatively minute and distributed devices, sensors, controllers, and along with nanotechnology allow scaling a variety of traditional mechanical or electro-mechanical designs and methods with electronic, electro-mechanical, digital logic, and/or processor or computer-controlled functionalities to the micro-scale. 
     A nano/micro electro-mechanical relay  60  provides some of the design functionality that can be used to provide a variety of nano/micro electro-mechanical digital relay circuits, some of which are described later in the disclosure. Certain embodiments of the nano/micro relay switch pairs  64  comprise at least one NO (normally open) nano/micro relay switch  80 , at least one NC (normally closed) nano/micro relay switch  82  and a nano/micro actuator  70 . As known with switch terminology, each NO nano/micro relay switch  80  and NC nano/micro relay switch  82  can be configured to be switched between the closed (e.g., on) position and the open (e.g., off) position. The normal position for each NO nano/micro relay switch  80  or NC nano/micro relay switch  82 , representing the position without actuation while the actuated position represents the respective position during actuation. As such, NO nano/micro relay switches would normally be open, but upon actuation are closed. By comparison, NC nano/micro relay switches are normally be closed, but open upon actuation. 
     One advantage of bringing the nano/micro electro-mechanical relay  60  to the nanoscale as well as to ULSI (ultra-large scale integration), or even lower levels, is that such structures can be fabricated using techniques presently being applied for transistor-based devices, such as complementary metal oxide semiconductor (CMOS). Many transistor-based switching devices rely on biasing the different terminals of the transistor to alter the electric current passing through the transistor. By comparison, certain embodiments of the nano/micro electro-mechanical relay can provide switching functionality based on an electrically controlled mechanical displacement of at least part of the nano/micro relay switch pair  64  resulting largely by actuating the nano/micro relay switch pair  64 . 
     Certain embodiments of the nano/micro actuator  70  are configured to mechanically displace or reposition the nano/micro contact bar  72 , which acts to support portions of the nano/micro relay switch pair  64 , between their respective normal and actuated positions. Certain embodiments of the nano/micro actuator  70  of the nano/micro electro-mechanical relay  60  acts to transition the nano/micro relay switch pair  64  into their actuated positions by bending the nano/micro actuator  70 , and thereby displacing the nano/micro contact bar  72  and the attached nano/micro relay switch pair  64 , out of or into the paper relative to the viewer. Displacements by which the nano/micro contact bar  72  that supports the NO nano/micro relay switch  80  and NC nano/micro relay switch  82 , acts to displace such relay switches  80 ,  82  out of or in to the paper in  FIG. 1 . A variety of configurations and embodiments of the nano/micro relay switch pair  64  can thereby be operationally transitioned between their normal and actuated positions by displacing certain embodiments of the nano/micro electro-mechanical relay  60 , as described in this disclosure. 
       FIG. 1  shows an etch hole  126  that is formed into the actuator  70 . By configuring certain etch hole(s)  126  as desired, a single nano/micro actuator  70  can be subdivided into multiple smaller nano/micro actuators  70 . The dimensions, configurations, materials, and the etch holes formed within the actuator  70  is a design choice, and not intended to be limiting in scope. For satisfactory electrical designs, the electrical contacts must remain sufficiently spaced from other electrical contacts or connectors of the nano/micro electro-mechanical relay  60  (such as conductive traces  84  and other electric contact members as described herein, for example). As such, trenches, or other spaces, can be formed between the actuator  70  and any other electric contact member that is likely to limit any electrical current flow, interference, or noise between the actuator  70  and other contacts. 
       FIG. 2  shows one embodiment of the nano/micro electro-mechanical relay  60 , as viewed through sectional lines  2 - 2  of  FIG. 1 . Also shown is a dotted-line outline of an at least one substrate  120  that supports the nano/micro electro-mechanical relay. The nano/micro actuator comprises a piezoelectric stack  94  and elastic layers  102 . During actuation, the nano/micro actuator  70  deflects such as by bowing up at the right side as a result of a force in the direction indicated by arrow  124 . This force  124  is applied over a greater area by the piezoelectric stack layers  94 , but results in a deflection to the nano/micro contact bar  72 . With such deflection, the NO nano/micro relay switch  80  and the NC nano/micro relay switch  82  (both attached to and supported by nano/micro contact bar  72 ), are both displaced upward as shown by the arrow  118 . Such mechanical upward displacement of certain portions of the NO nano/micro relay switch  80  and the NC nano/micro relay switch  82  transitions these nano/micro relay switches from the normal position to the actuated position. 
     As soon as the nano/micro actuator  70  ceases applying the actuating force it is no longer being deflected into the actuated position, and it returns to the normal position due largely to the spring constant or stored elastic energy of the actuatable segment  68  and can be augmented through applying a voltage (less than the coercive voltage of the piezoelectric layer  205 ) in the opposite polarity of the aforementioned actuation voltage. The nano/micro contact bar  72  (supporting the displaceable portions of the NO nano/micro relay switch  80  and NC nano/micro relay switch  82 ) then returns from the actuated position to their normal position. Since both the NO nano/micro relay switch  80  and the NC nano/micro relay switch  82  are supported by and attached to the nano/micro contact bar  72 . As the nano/micro contact bar  72  transitions between the normal and actuated positions, so do the NO nano/micro relay switch  80  and the NC nano/micro relay switch  82 . An array of the nano/micro relay switch pairs  64  could be provided. Provided each one of the nano/micro relay switch pair  64  in the array were being simultaneously actuated or deactuated, the various relay switches could act simultaneously. Such simultaneous actuation and de-actuation would be important for such data-centric applications as memories, data transfers, shift registers, microcomputers, etc. 
     The at least one substrate  120  supports the nano/micro actuator  70 , the nano/micro contact bar  72 , and the anchored contact segment  74 . The layers of the anchored contact segment  74  are attached to the substrate  120 , and can be considered a unitary portion. During operation, the anchored contact segment  74  exhibits little or no flex due to the connection to the substrate  120 . The anchored contact segment  74  each has a number of NO conductive traces  84   a  and  84   b  (both in electric communication with the NO nano/micro relay switch  80 ); as well as a number of NC conductive traces  84   c  and  84   d  (both in electric communication with the NC nano/micro relay switch  82  mounted thereupon). 
     Certain embodiments of the nano/micro actuator  70  includes the layers of the piezoelectric stack layers  94  combined with the layers of the elastic layers  102 . All adjacent layers referenced relative to the figures as  201 ,  202 ,  203 ,  204 ,  205 , and  206  are illustrated as being attached or bonded to adjacent layers, so the layers may be viewed as moving as a unitary non-homogenous member forming the nano/micro actuator or the nano/micro contact bar. 
     Certain embodiments of the nano/micro actuator  70  rely, during actuation, upon the interaction between the elastic layers  102  and the piezoelectric stack layer  94 . In general, the elastic layers  102  are easily laterally bendable (bend up and down as viewed in  FIG. 2  in the direction shown by arrow  118 ), but have considerable resistance to compression or expansion in a direction perpendicular to the left or right as viewing  FIG. 2 . 
     Certain embodiments of the set of elastic layers  102  include a first elastic layer  201 , a second elastic layer  202 , and a third elastic layer  203 . The structure of the first elastic layer  201 , the second elastic layer  202 , and the third elastic layer  203  also extends into the nano/micro contact bar  72 . The first elastic layer  201  can include, for example, silicon dioxide or other suitable material that might be but does not have to be a dielectric material. The second elastic layer  202  can include, for example, silicon nitride or other suitable material that might be but does not have to be a dielectric material. The third elastic layer  203  can include, for example, silicon dioxide or other suitable dielectric to act as an electric insulator and limit electric current flowing from the actuator electrode layer  204  through the elastic layers  102 , conductive traces  84 , the substrate  120 , and/or electric ground attached to the substrate. Though three layers  201 ,  202 , and  203  are illustrated in the elastic layers  102 , a greater of lesser number of layers could be used, and the number of layers or configuration of these layers represents a design choice. It is important that at least one of these layers includes a dielectric material for the above electrical insulating reason. The particular materials or thicknesses as described relative to  FIG. 1 , and other places through this disclosure, are a design choice and is not intended to be limiting in scope. Instead of utilizing silicon-based technologies, certain embodiments of the elastic layers  102  or other portion of the nano/micro electro-mechanical relay  60  can utilize gallium arsenide or other well-known semiconductor technologies. A variety of device and substrate configurations, designs, and materials can be integrated to allow flexibility. 
     The piezoelectric stack layers  94  contracts when a suitable electric voltage is applied between the actuator electrode layers  204  and  206  to actuate the piezoelectric stack layers  94  of the nano/micro actuator  70 . Each of the layers forming both the elastic layers  102  and the piezoelectric stack layers  94  (i.e.,  201 ,  202 ,  203 ,  204 ,  205 , and  206 ) may be viewed as bonded to their adjacent layers or layer. As such, as the piezoelectric actuator layer  205  starts contracting during actuation (caused by a suitable bias voltage being applied across actuator electrode layers  204  and  206 ), the elastic layers  102  tend to deflect laterally in the general direction shown by arrow  124  in the direction towards the contracting piezoelectric stack layers  94 . In addition to the nano/micro actuator  70  being deflected, the nano/micro contact bar  72  is also forced upwards, that in turn displaces deflectable portions of both the NO nano/micro relay switch  80  and NC nano/micro relay switch  82  upwardly into their actuated positions. 
       FIG. 3  is a top view of one embodiment of a nano/micro electro-mechanical relay  60 . Certain embodiments of the NO conductive traces  84   a  and  84   b , and NC conductive traces  84   c  and  84   d , are illustrated as extending across and being attached to the nano/micro contact bar  72 . Operationally, the conductive traces  84   a - 84   d  are not configured in the nanoscale or MEMS level, and might well, for instance, provide a location for electric contacts or interconnects to be made to other circuits. The nano/micro actuator  70  (comprising elastic layers  102  and the piezoelectric stack layers  94 ) and the nano/micro contact bar  72  can together provide deflecting structural support for portions of certain embodiments of NO nano/micro relay switches  80  and NC nano/micro relay switches  82 . Such structures can provide sufficient flexibility such as to allow deflection of the associated nano/micro relay components (e.g., supported by the nano/micro contact bar  72 ) during actuation. 
     Such deflection can result in, for example, the NO nano/micro relay element being deflected to its closed position or alternately in a NC nano/micro relay element position being deflected to its open position. Such deflection can occur under the influence of distortion of the nano/micro actuator  70 , and can require some degree of flexibility within each of the deflectable elements of the actuatable segment  68 , such as between the nano/micro actuator  70  and the associated nano/micro contact bar  72 . Making the elastic layers  102  of the nano/micro actuator  70  and/or the nano/micro contact bar  72  suitably flexible can at least partially enable such deflections by the nano/micro actuator  70 . 
     Certain embodiments of the nano/micro electro-mechanical relay  60  are secured on and mounted to the substrate  120 . The substrate  120  includes support substrate faces  121  formed thereupon, with a release etch trench  122  formed within a portion of the support substrate face. A considerable portion of the nano/micro actuator  70  and the nano/micro contact bar  72  is formed above the release etch trench  122  and as such is not affixed to the substrate  120 , and can thereby be deflected by pressure applied by the nano/micro actuator  70  including the piezoelectric stack layers  94  as shown at  124 . 
     The entire length of the anchored contact segments  74  is attached to the substrate  120 , and as such the anchored contact segments remains stationary relative to the substrate. The anchored contact segments  74  is therefore not susceptible to deflections from applied forces from the nano/micro actuator  70  in a direction represented generally by arrow  124 . Within this disclosure, any pad or cantilever that is affixed to the anchored contact segment  74  is referred to respectively as a substrate anchored pad or substrate anchored cantilever. During actuation, the nano/micro actuator  70  exhibits a bowing deflection depending upon the configuration of the piezoelectric stack layers  94 , that results in deflection of the nano/micro contact bar  72  as well as the supported portions of the NO nano/micro relay switch  80  and NC nano/micro relay switch  82  that are displaced during actuation, as shown by arrow  118 . Within this disclosure, pads or cantilevers that are affixed to the NO nano/micro relay switch  80  or the NC nano/micro relay switch  82 , and therefore move along with the switches can be referred to as displaceable contact pads (also contact pads) or displaceable contact cantilevers (also contact cantilevers). 
     Certain stationary portions of the NO nano/micro relay switch  80  and NC nano/micro relay switch  82  (such as substrate anchored cantilevers and substrate anchored pads, as described below) are supported by and remain stationary relative to the anchored contact segments  74 . This relative deflection with respect to a fixed surface causes both the NC nano/micro relay switches  82  and the NO nano/micro relay switches  80  to change states. By comparison, support substrate face  121  of the substrate  120  supports, and is attached to, virtually the entire anchored contact segment  74 , and thereby the anchored contact segment  74  remains relatively rigid during actuation. The anchored contact segment  74  is maintained substantially fixed along most of its surface area to the substrate  120 , and therefore any motion by the other nano/micro relay switches  80 ,  82  can be countered by the anchored contact segment  74  as if it is a part of the substrate  120 . 
     During operation, the NO nano/micro relay switch  80  remains in its normal open state until actuated, at which time it is displaced into its closed state. Conversely, the NC nano/micro relay switch  82  remains in its closed state until actuated, at which time it is displaced into its open state. As a result of concurrent movement of all members being actuated from the nano/micro contact bar  72 , actuation can simultaneously actuate or deactivate both the NO nano/micro relay switches  80  and the NC nano/micro relay switches  82 . There can be a variety of arrangements, materials, and configurations of NO nano/micro relay switches  80  and/or NC nano/micro relay switches  82  (or even extensive or varied arrays in certain embodiments). 
     Certain embodiments of the nano/micro actuator  70 , when actuated or de-actuated such as by an application of electrical current, can be configured to cause a corresponding deflection of at least a portion of the nano/micro contact bar  72  as shown by arrow  118 . The nano/micro actuator  70  can be configured to include the piezoelectric actuator layer  205  or other similar material, such as to provide a contraction based on application of electric voltage. Internal flexibility of the elastic layers  102  provides for deflection of the nano/micro actuator  70  and the nano/micro contact bar  72 . Particularly, during actuation, the nano/micro actuator  70  contracts causing the nano/micro actuator  70  to flex upwardly and generally forcing the nano/micro contact bar  72  such as including supporting the NO nano/micro relay switch  80  and the NC nano/micro relay switch  82  to be displaced upwardly in the direction of the arrow  124  during actuation. To deactuate certain embodiments of the NO nano/micro relay switch  80  and NC nano/micro relay switch  82 , the opposed process to that described in this paragraph is followed such that the nano/micro contact bar  72  is returned to its normal position from its actuated position. The overall configurations, dimensions, and materials of the piezoelectric stack layer  94  relative to the elastic layers  102  are selected to determine the amount of displacement of the nano/micro relay switches  80  and  82 . 
     Within this disclosure,  FIGS. 3 to 5  illustrate a number of embodiments of the NO nano/micro relay switch  80  and the NC nano/micro relay switch  82 . Certain embodiments of the NO nano/micro relay switch  80  can include some combination of substrate-anchored cantilevers  210   a  and  210   b  and substrate anchored pads  218  that remain stationary relative to the anchored contact segments  74  and the substrate  120 . Certain embodiments of the NC nano/micro relay switch  82  can include displaceable contact cantilevers  209   c ,  209   d  and contact pads  208  that move with the nano/micro contact bar  72 . In general, conductive cantilevers interact with conductive pads and have a variety of nano/micro switch contacts  96  switchably connected therebetween. Each displaceable contact cantilever  209  or displaceable contact pad  208  can be displaced along with the nano/micro contact bar  72  because it is attached thereto such as being fabricated thereto using semiconductor processing techniques. Each fixed substrate-anchored cantilever  210  or substrate anchored pad  218  extends in contact with certain embodiments of the anchored contact segment  74 . As such, displacement of the at least one nano/micro actuator  70  respectively upwardly or downwardly (during actuation or deactuation) can move each displaceable switch component either into contact or out of contact with its mating fixed switch contact. Any substrate-anchored cantilevers  210  or substrate anchored pads  218  that is affixed to the anchored contact segments  74  can, for all practical purposes, be considered as being fixedly attached to the substrate  120 . 
       FIG. 4  illustrates a partial cross-sectional view of one embodiment of a nano/micro electro-mechanical relay  60  as taken through sectional lines  4 - 4  of  FIG. 3 . Also shown is a dotted outline is a supporting substrate structure. Certain components could function as an embodiment of the NO nano/micro relay switch  80 . The  FIG. 4  shows one embodiment of the NO nano/micro relay switch  80  includes two NO substrate-anchored cantilevers  210   a,b , which are respectively attached to a first terminal of each respective pair of distinct NO conductive traces  84   a,b . When actuated, opposite ends of the NO contact pad  208  are in electrical contact with the two NO substrate-anchored cantilevers  210   a,b . To establish electrical communication between the NO contact pad  208  and the NO conductive traces  84   a,b ;  FIG. 4  illustrates the nano/micro switch contacts  96   a,b  that includes conductive dimples  97   a,b  that are respectively electrically coupled to the NO substrate-anchored cantilevers  210   a,b . The nano/micro switch contacts  96   a,b  also includes conductive counter dimples  98   a,b  that are respectively electrically coupled to opposite terminals of the NO contact pad  208 . 
     During operation, the NO contact pad  208  (and also the conductive counter dimples  98   a,b  attached thereto) is deflected between normal and actuated positions in a direction shown by arrow  118  by the nano/micro contact bar  72 . A closed circuit defining the NO nano/micro relay switch  80  is formed as the conductive counter dimple  98   a  comes in close electrical proximity with, or contacts, the conductive dimple  97   a ; and the conductive counter dimple  98   b  also comes in close proximity (or contact) with the conductive dimple  97   b . Upon this electrical contact or proximity of the nano/micro switch contacts  96   a  and  96   b , a closed circuit defines the NO nano/micro relay switch  80  around a loop including the NO conductive trace  84   a , the NO substrate-anchored cantilever  210   a , the conductive dimple  97   a , the conductive counter dimple  98   a , the NO contact pad  208 , the conductive counter dimple  98   b , the conductive dimple  97   b , the NO substrate-anchored cantilever  210   b , and the NO conductive trace  84   b.    
       FIG. 5  illustrates a partial cross-sectional view of one embodiment of the nano/micro electro-mechanical relay  60  as taken through sectional lines  5 - 5  of  FIG. 3 . Certain components that could function as an embodiment of the NC nano/micro relay switch  82  are illustrated. The  FIG. 5  embodiment of the NC nano/micro relay switch  82  includes a pair of respective NC contact cantilevers  209   c,d  that can be controllably electrically switched into electrical communication with each respective NC conductive traces  84   c,d . The NC contact cantilevers  209   c,d  rest directly on, and are mounted to, the nano/micro contact bar  72 , and are electrically isolated thereby. To provide the controllable electrical contacts between each of the NC contact cantilevers  209   c  and  209   d  and the respective NC conductive traces NC conductive trace  84   c  and  d ,  FIG. 5  illustrates the nano/micro switch contacts  96   c,d  that includes a pair of conductive dimples  97   c,d  and a pair of conductive counter dimples  98   c,d . Each of the conductive dimples  97   c,d  is in direct electrical communication and physical contact (by being mounted to) respective NC contact cantilevers  209   c,d . The two NC contact cantilevers  209   c,d  are physically and electrically conductive with each other, and as such electric current is free to flow therebetween. Each of conductive counter dimples  98   c,d , is in direct electrical communication and physical contact (by being mounted to) respective NC conductive trace  84   c  and  84   d . During operation, the NC contact cantilevers  209   c  and  209   d  are displaced between normal and actuated positions as shown by arrow  118 . As the conductive counter dimple  98   c  is removed from close electrical proximity (or contact) with the conductive dimple  97   c , then the conductive counter dimple  98   d  also is removed from close proximity (or contact) with the conductive dimple  97   d . Upon this electrical contact or proximity, a closed circuit is defined by NC conductive trace  84   c , conductive counter dimple  98   c , conductive dimple  97   c , NC contact cantilever  209   c , NC contact cantilever  209   d , conductive dimple  97   d , conductive counter dimple  98   d , and NC conductive trace  84   d.    
     The field of electrical contacts is generally well understood by those skilled in the art. As such,  FIGS. 4 and 5 , and the associated disclosure, is intended to show generalized components describing nano/micro switch contact  96  including conductive dimple  97  and conductive counter dimple  98 . 
     Considering the embodiments of the nano/micro electro-mechanical relay  60  including the nano/micro relay switch pair  64  as described with respect to  FIGS. 3 to 5 , consider that for each NO nano/micro relay switch  80  and NC nano/micro relay switch  82 , there is a respective pair of NO conductive traces  84   a,b  or NC conductive traces  84   c,d  in electrical communication therewith. The pair of conductive traces  84  may be considered as conductors to more macro-electronics such as electrical connections. Each conductive trace  84   a  to  84   d  has to pass across the junction between the nano/micro contact bar  72  and the anchored contact segment  74 , thereby necessitating some type of electrical contact cantilever, some type of electrical contact pad, and some type of nano/micro switch contact  96  operating as a switch between the cantilever and the pad based on motion of the cantilever or the pad. As such, each NO nano/micro relay switch  80  and NC nano/micro relay switch  82  connects to two conductive traces  84 , and therefore is actually made up of two identical nano/micro switch contacts  96 , not one. One switch contact is necessary for each conductive trace  84  that passes across the junction between the nano/micro contact bar  72  to the anchored contact segments  74 . Each of these nano/micro switch contacts  96  function similar to the other as the nano/micro relay switch pair  64  becomes actuated or deactuated, and moves up and down simultaneously with the nano/micro actuator bar  72 . 
     NO nano/micro relay switches  80  can be simultaneously actuated with the NC nano/micro relay switches  82 . Such simultaneous actuation and deactuation of multiple nano/micro relay switches (or even arrays thereof), between their normal states and actuated states, would be highly desired for digital logic circuits that often rely upon having a variety of logic gates operate simultaneously for each device, where many of the devices act in concert is well known throughout the computer, controller, automation, robotics, and other such digital applications. This disclosure thereby can be used to provide a variety of digital relay circuits  79 , comprising pairs of NO nano/micro relay switches  80  and NC nano/micro relay switch  82 . Integral digital relay circuits  79  can contribute to form a variety of digital devices such as adders, memory elements, microcontrollers, and even combinations of such devices as described in this disclosure. 
     Certain embodiments of the nano/micro electro-mechanical relay  60  can be used to perform digital operations. A true Boolean value can be defined by the output voltage being greater than an average voltage value. A false Boolean value can be defined by the output voltage being less than the average voltage value. Certain embodiments of the nano/micro electro-mechanical relay  60  can function as a six terminal device that can provide digital logic. Two NC conductive traces  84   c ,  84   d  can be referred to as normally closed outputs. Two NO conductive traces  84   a ,  84   b  can be referred to as the normally open outputs. Based on wiring, certain embodiments of the nano/micro electro-mechanical relay  60  can perform all 16 uniquely differentiable 2-input Boolean functions. 
     An electrical voltage bias can be applied to certain embodiments of the nano/micro electro-mechanical relay  60  to reduce the overall swing voltage necessary to change between normal and actuated states. Such electrical voltage bias causes a reduction in dynamic power necessary to change the states between normal and actuated. The total power is reduced by using the nano/micro electro-mechanical relay  60  configuration since the leakage current (which can be equated to leakage power) of the electrical voltage bias that is applied between the actuator electrode layers  204  and  206  through the piezoelectric actuator layer  205  is very low. Applying such electrical voltage bias reduces switching time, since less charge is necessary to transition the nano/micro actuator  70  from one state to another, and also because the gap is reduced between conductive dimple  97  and conductive counter dimple  98 . From this, the general electro-mechanical operation of certain embodiments of the nano/micro switch pair  64  can be very good whether being used digitally such as in arrays, or being used as discrete devices. 
     Certain embodiments of the nano/micro electro-mechanical relay  60  can be used as a low-leakage technique for clock-gating either a pure mechanical, or a hybrid mechanical-electronics system to reduce the overall power consumption and provide capacitance. Certain embodiments of the nano/micro electro-mechanical relay  60  can also be used as a low-leakage method for removing parts of a system from a power grid, or other electrical circuits. As such, the nano/micro electro-mechanical relay  60  can provide electrical isolation. 
       FIG. 6  is a top view of another embodiment of a nano/micro electro-mechanical relay  60 , which is configured to include the nano/micro relay switch pair  64 . The NO nano/micro relay switch  80  is in electrical communication with the NO conductive trace  84   a  that extends over and is affixed to the anchored contact segment  74 , and the NO conductive trace  84   f  that extends over and is affixed to the nano/micro actuator  70 . The NO conductive trace  84   a  is in electrical communication with the NO substrate-anchored cantilever  210 , while the NO conductive trace  84   f  is in electrical communication with the NO contact pad  208 . The nano/micro switch contact  96   a  includes relatively displaceable conductive dimple  97   a  attached to the NO substrate-anchored cantilever  210  and also the conductive counter dimple  98   a  electrically connected to the NO contact pad  208  and the NO conductive trace  84   f . The nano/micro switch contact  96   a  therefore provides for the electrical connection between the NO substrate-anchored cantilever  210  and the NO contact pad  208  as a result of the vertical motion of the nano/micro contact bar  72  (the motion provided by the nano/micro actuator  70 ) between its actuated and normal positions. As such, an electrical path associated with the NO nano/micro relay switch  80  extends from the NO conductive trace  84   a , the NO substrate-anchored cantilever  210 , the conductive dimple  97   a , the conductive counter dimple  98   a , the NO contact pad  208 , and the NO conductive trace  84   f.    
     Certain embodiments of the NC nano/micro relay switch  82 , as described with respect to  FIG. 6 , is in electrical communication with both the NC conductive trace  84   c  that extends over and is affixed to the anchored contact segment  74 , and the NC conductive trace  84   h  that extends over and is affixed to the nano/micro actuator  70 . The NC conductive trace  84   c  is in electrical communication with the substrate anchored pad  218 , while the NC conductive trace  84   h  is in electrical communication with the NC contact cantilever  209 . The nano/micro switch contact  96   c  includes relatively displaceable conductive counter dimple  98   c  attached to the substrate anchored pad  218  and also the conductive dimple  97   c  electrically connected to the NC contact cantilever  209 . The nano/micro switch contact  96   c  therefore provides for the electrical connection between the NC contact cantilever  209  and the substrate anchored pad  218  based on the vertical motion of the nano/micro contact bar  72  (the motion provided by the nano/micro actuator  70 ) between its actuated and normal positions. As such, an electrical path associated with the NC nano/micro relay switch  82  extends from the NC conductive trace  84   c , the conductive counter dimple  98   c , the conductive dimple  97   c , the NC contact cantilever  209 , and the NC conductive trace  84   h.    
     A certain percentage of relatively high-frequency electrical signals applied to either conductive trace associated with NO or NC nano/micro relay switches  80 ,  82 , when open, flows to the corresponding conductive trace due to electrical capacitance formed across capacitive plates (formed by the conductive dimple  97  and the conductive counter dimple  98 ) of the included nano/micro switch contact  96 . By comparison, lower frequency signals are nearly entirely attenuated by the capacitance of the capacitive plates formed by the nano/micro switch contact  96  associated with NO or NC nano/micro relay switches  80 ,  82  (when open). As such, spacing between the conductive dimple  97  and the conductive counter dimple  98  can be selected, designed, or adjusted to vary the frequencies of signals transmitted or attenuated through each nano/micro switch contact  96  (when in the open position). The above describes one embodiment of capacitive coupling as provided by the conductive dimple  97  and the conductive counter dimple  98 . By comparison, a capacitive coupling can also exist, as well as be designed for, between or within the conductive trace lines  84   a  to  84   d ,  84   f , and  84   h  for similar purposed, for example. 
     Both the NO set including the NO substrate-anchored cantilever  210  and NO conductive traces  84   c, f ; as well as the normally closed set including NC contact cantilever  209  and its NC conductive traces  84   c  and  84   h , may be viewed as forming a single contact point where the voltages are at a single level when the respective NO nano/micro relay switches  80  are actuated or closed. 
     The location, configuration, and dimensions of the piezoelectric stack layers  94  define the operational characteristics of the nano/micro actuator  70 . Those embodiments of the nano/micro actuator  70  that have the piezoelectric stack layers  94  deposited thereupon contributes to the bending of the nano/micro actuator  70 . As such, different nano/micro electro-mechanical relay  60  may be configured differently during fabrication by having different length, width, depth, or other configuration of the nano/micro actuators  70 . Those nano/micro electro-mechanical relays  60  with longer nano/micro actuators  70  would require a lesser voltage to transition between normal and actuated states. The voltage level at which the voltage that each active nano/micro relay switch  80 ,  82  transitions between normal and active states could be designed, calibrated, or confirmed. 
     A variety of NO nano/micro relay switches  80  can be configured as an analog to digital (ND) converter in which the calibrated transition value for each device could be determined. Different ones of the NO nano/micro relay switches  80  have nano/micro actuators  70  that have different lengths or other dimensions, and each NO nano/micro relay switch  80  deflects a different distance based on their length at a given bias voltage with those NO nano/micro relay switches  80  having a longer nano/micro actuator  70  deflecting further at the same bias voltage. The maximum deflection can be set for each NO nano/micro relay switches  80 , in certain embodiments. The established ranges set up between the calibrated values for successive NO nano/micro relay switches  80 . As such, during operation, all those different NO nano/micro relay switches  80  whose calibrated voltage value is below that of the applied voltage would be actuated, and those different nano/micro relay switches  80 ,  82  whose calibrated voltage value is above that of the applied voltage would not be actuated. For instance, assuming that there are eight NO nano/micro relay switches  80  for a particular ND converter, between 0 and 8 NO nano/micro relay switches  80  is closed at any given voltage. A digital output value of “11100000” would indicate that the actual analog value is between the calibrated value of the third NO nano/micro relay switch  80  and the fourth. The range above the nano/micro relay switches  80 ,  82  with the highest calibrated voltage value would indicate the range of the actual applied voltage in a digital manner. 
     There are a number of nano/micro electro-mechanical digital relay circuits  66  that can be configured with one or more nano/micro electro-mechanical relays  60 .  FIG. 7  shows a schematic diagram of one embodiment of a relaxation oscillator  300  that can be fabricated using the nano/micro electro-mechanical relay  60 . For example,  FIG. 7  shows a schematic diagram of one embodiment of a relaxation oscillator  300  that can be fabricated comprising the NO nano/micro relay switch  80  of the nano/micro electro-mechanical relay  60  (the NC nano/micro relay switch  82  is not involved in this relaxation oscillator configuration), a voltage source  302 , and external resistors  304  and  306 . The electrical resistance of resistor  306  is considerably less than that of resistor  304 . As per  FIG. 7 , a feedback loop  310 , set at the output voltage for the relaxation oscillator, forms by electrically coupling NO conductive trace  84   b  to one terminal of the resistor  304  and also the actuator electrode layer  206  of the piezoelectric stack layers  94 . The actuator electrode layer  206  of the piezoelectric stack layers  94  is electrically grounded. The voltage source provides voltage to the other terminal of the external resistor  304 . The NO conductive trace  84   b  is electrically grounded via resistor  306 . 
     During operation, the voltage supplied by voltage source  302  incrementally increases Vout, which is also applied at the electric contact of the actuator electrode layer  206 . The actuator electrode layer  204  is grounded. Vout builds to a level actuating the nano/micro actuator  70 , which actuates the NO nano/micro relay switch  80  causing the latter to close. Once the NO nano/micro relay switch  80  closes, the voltage at Vout discharges through the low resistance resistor  306  providing a low resistance pathway to ground and quickly returning the NO nano/micro relay switch  80  to its normal, open condition. The operation process of this paragraph repeats itself to produce the oscillation. 
       FIG. 8  shows a schematic diagram of one embodiment of a dynamic latch  320  that can be fabricated using one nano/micro electro-mechanical relay  60  and a capacitive element  322 . Certain embodiments of the capacitive element  322  can be configured as portion of another NO nano/micro relay switch  80  (using the conductive dimple and conductive counter-dimples to form two spaced capacitive plates when open), or alternately a distinct capacitor. An input is applied to input terminal  324 , which is in electrical communication with NC conductive trace  84   d . An electric voltage source V 0  is electrically applied between NO conductive trace  84   b  and NC conductive trace  84   c , and also one terminal of capacitive element  322 . An output terminal  326  is in electrical communication with the NO conductive trace  84   a . The actuator electrode layer  206  can be grounded, but in an alternate configuration, not shown, it can be tied to an arbitrary potential (such as the high voltage rail) to alter the sequential throughput of the element in that circuit. If the actuator electrode layer  206  is attached to the high voltage rail, then the clock signal at the phase output φ becomes inverted, so the states for the clock signal would be reversed. The phase φ is output from the phase output terminal  328  to the actuator electrode layer  204 . 
     During operation of the dynamic latch  320 , the normal state of the nano/micro electro-mechanical relay  60  allows the input terminal  324  to charge or discharge the capacitive element  322  while isolating the output terminal  326 . By comparison, when activated, the nano/micro electro-mechanical relay  60  isolates the input terminal  324  from charging or discharging the capacitive element  322 , and the output terminal  326  electrically couples to charge or discharge the capacitive element  322 . In this configuration, the nano/micro electro-mechanical relay  60  acts both as data storage and retrieval. This device utilizes only one nano/micro electro-mechanical relay  60 , which compares to in CMOS design where at least 2 MOSFETS (and typically 4 to limit signal degradation) would be used. The dynamic latch  320  configured with the capacitive element  322  would be expected to maintain its charged state (or uncharged state) for a considerable time such as to allow a temporary interruption in power. 
       FIG. 9  shows a schematic diagram of one embodiment of a dynamic latch with buffer  340  that can be fabricated by combining a nano/micro electro-mechanical relay  60   a  configured as a dynamic latch  360  (similar in structure and operation as the dynamic latch  320  described in  FIG. 8 ), a nano/micro electro-mechanical relay  60   b  configured as a buffer  362 , a least one capacitive element  322 , and associated circuitry. The dynamic latch  360  comprises the nano/micro electro-mechanical relay  60   a , while the buffer  362  comprises the nano/micro electro-mechanical relay  60   b . Each nano/micro electro-mechanical relay  60   a  and  60   b  is as described above and the reference characters are consistent except where now noted. The NO conductive trace  84   b  and NC conductive trace  84   c  of the buffer  362  is in electrical communication with an input terminal  344 . A power rail  350  is in electric communication with NO conductive trace  84   a  of buffer  362 . NC conductive trace  84   d  and actuator electrode layer  206  of buffer  362  are both grounded. 
     An output terminal  346  is in electrical communication with NO conductive trace  84   a  of the dynamic latch  360 . The NC conductive trace  84   d  of dynamic latch  360  electrically communicates to the actuator electrode layer  204  of the buffer dynamic latch  360 . The output phase terminal  348  electrically couples to actuator electrode layer  204  of the dynamic latch  360 . The buffer  360  acts to drive higher capacitance loads within the capacitive element  322 , and would allow the data to be maintained for an extended period (e.g., perhaps hours) that is related to leakage through piezoelectric actuator layer  205  of the dynamic latch  360 . The buffer  362  also allows new data to be written into and maintained for a considerable duration by the capacitive element  322  of the dynamic latch  360 , while the previous piece of data is being used elsewhere in the nano/micro electro-mechanical digital relay circuit  66 . As such, the dynamic latch with buffer  340  includes two nano/micro relay switch pairs  64 , instead of certain current CMOS designs that use at least 4 MOSFETS, and typically 6 to limit signal degradation. 
     Additionally, though not shown, two dynamic latches with buffer  340 , of the type described with respect to  FIG. 9 , could be further combined to provide a dynamic flip-flop with edge sensitivity to the storage process for mechanical logic. To make such a modification to the two dynamic latches  340  of  FIG. 9 , the input terminal  344  of a first dynamic latch  340  is electrically coupled only to the NO conductive trace  84   a  of the second dynamic latch  340 . During operation, the values stored in one dynamic latch  340  are sequentially passed to the other dynamic latch during each clock cycle. The dynamic flip-flop can be fabricated using four nano/micro relay switch pairs  64   a  and  64   b  (two of each for both flip flop) while still providing excellent operation instead of often more switch-type devices with CMOS designs. As such, a variety of sophisticated yet durable devices can be fabricated using arrays of nano/micro relay switch pairs  64 , and such devices may be fabricated using relatively few devices and chip real estate while limiting current loss during operation. Additionally, arrays of nano/micro relay switch pairs  64  can be inexpensively fabricated yet made with robust operating parameters, even to allow devices to be crafted to be radiation hardened, and exposed to severe climate conditions, etc. for varied military or civilian applications. Certain devices could be expected for aviation, space, nuclear containment, internal engine, or other such harsh environments; as with many discrete electromechanical relays. Such devices can be used in combination with, or in place of, many CMOS or other transistor-based devices for such computer or communication device applications as with processors, memories, logic gates, switching matrices, power gating, etc. 
     Various elements, devices, modules and circuits are described above in associated with their respective functions. These elements, devices, modules and circuits are considered means for performing their respective functions as described herein. 
     While the foregoing is directed to embodiments of the present invention, other and further embodiments of the invention may be devised without departing from the basic scope thereof, and the scope thereof is determined by the claims that follow.