Patent Publication Number: US-2010108534-A1

Title: Electrochemical actuator

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
     This application relates to U.S. patent application Ser. No. (to be assigned) (Attorney Docket No. 2137.018), filed on the same day as the present patent application, and titled “ELECTROCHEMICAL ACTUATOR”; and U.S. patent application Ser. No. (to be assigned) (Attorney Docket No. 2137.018A), filed on the same day as the present patent application, and titled “ELECTROCHEMICAL ACTUATOR” the contents of which are both incorporated herein by reference. 
    
    
     FIELD OF THE INVENTION  
     This invention relates generally to actuators, and more particularly, to electrochemical actuator&#39;s and methods for providing actuation to mechanical systems. 
     BACKGROUND OF THE INVENTION  
     There are many products and processes requiring very small actuators and valves such as portable devices and devices that have packaging limitations on size. One example industry is the consumer electronics industry and another is the medical industry. An example product in the electronics industry utilizing such small actuators and valves is a fuel cell system as described below. 
     Fuel cells are devices in which electrochemical reactions are used to generate electricity. A variety of materials may be suited for use as a fuel depending upon the nature of the fuel cell. Organic materials, such as methanol, are attractive fuel choices due to their high specific energy. 
     Direct oxidation fuel cell systems may be suited for utilization in smaller mobile devices (e.g., mobile phones, handheld and laptop computers), as well as in some larger scale applications. In fuel cells of interest here, a carbonaceous liquid fuel in an aqueous solution (typically aqueous methanol) is applied to the anode face of a membrane electrode assembly (MEA). The MEA contains a layer of membrane electrolyte which may be a protonically conductive, but electronically non-conductive membrane (PCM or membrane electrolyte). Typically, a catalyst, which enables direct oxidation of the fuel on the anode aspect of the PCM, is disposed on the surface of the PCM (or is otherwise present in the anode chamber of the fuel cell). In the fuel oxidation process at the anode, the products are protons, electrons and carbon dioxide. Protons (from hydrogen in the fuel and water molecules involved in the anodic reaction) are separated from the electrons. The protons migrate through the PCM, which is impermeable to the electrons. The electrons travel through an external circuit, which includes the load, and are united with the protons and oxygen molecules in the cathodic reaction, thus providing electrical power from the fuel cell. 
     One example of a direct oxidation fuel cell system is a direct methanol fuel cell system or DMFC system. In a DMFC system, a mixture comprised predominantly of methanol and water is used as fuel (the “fuel mixture”), and oxygen, preferably from ambient air, is used as the oxidizing agent. The fundamental reactions are the anodic oxidation of the methanol and water in the fuel mixture into CO 2 , protons, and electrons; and the cathodic combination of protons, electrons and oxygen into water. 
     Direct methanol fuel cells are being developed towards commercial production for use in portable electronic devices. Thus, the DMFC system, including the fuel cell and the other components should be fabricated using materials and processes that are compatible with appropriate form factors, and are cost effective in commercial manufacturing. Furthermore, the manufacturing process associated with a given system should not be prohibitive in terms of associated labor or manufacturing cost or difficulty. 
     Typical DMFC systems include a fuel source, fluid and effluent management and air management systems, and a direct oxidation fuel cell (“fuel cell”). The fuel cell typically consists of a housing, hardware for current collection and fuel and air distribution, and a membrane electrode assembly (“MEA”) disposed within the housing. 
     A typical MEA includes a centrally disposed, protonically conductive, electronically non-conductive membrane (“PCM”). One example of a commercially available PCM is NAFION® a registered trademark of E.I. Dupont de Nemours and Company, a cation exchange membrane comprised of polyperflourosulfonic acid, in a variety of thicknesses and equivalent weights. The PCM is typically coated on each face with an electrocatalyst such as platinum, or platinum/ruthenium mixtures or alloy particles. On either face of the catalyst coated PCM, the electrode assembly typically includes a diffusion layer. The diffusion layer on the anode side is employed to evenly distribute the liquid fuel mixture across the anode face of the PCM, while allowing the gaseous product of the reaction, typically carbon dioxide, to move away from the anode face of the PCM. In the case of the cathode side, a diffusion layer is used to achieve a fast supply and even distribution of gaseous oxygen across the cathode face of the PCM, while minimizing or eliminating the collection of liquid, typically water, on the cathode aspect of the PCM. Each of the anode and cathode diffusion layers also assist in the collection and conduction of electric current from the catalyzed PCM. 
     It is important that the fuel cells for use in powering the smaller mobile devices described above be as small as possible such that it is convenient to carry the devices incorporating the fuel cells. Thus, it is desirable for the components forming the fuel cell systems be as small as possible while still providing adequate power to the devices. For example, it is desirable that actuators providing mechanical action or motion within such fuel cell systems be as small as possible while still providing sufficient power to perform such mechanical action or motion. For example, actuators could be switches, valves, regulators or other components providing mechanical action or motion within a fuel cell system or other devices requiring such actuators. Actuators and valves (e.g., 1-way, 2-way, variable) that are commercially available are too large for applications on the scale appropriate for handheld devices. For example, MEMS actuators and valves are limited in how large they can be made thereby making them impractical for applications in the millimeter scale and above. Alternative actuator technologies such as electrostatic, shape memory alloys, piezoelectric (e.g., stacks and Bimorph, hydraulic) all have limitations either in force available, displacement or cost leaving a significant technology gap for actuators and valves in the above MEMs but below conventional technology size range. 
     Thus, a need exists for small actuators to produce force, pressure, or motion for products in size sensitive industries, such as consumer electronics and medical devices. 
     SUMMARY OF THE INVENTION  
     The present invention provides, in a first aspect, a valve system which includes a gas generator coupled to a first chamber and a passage for conveying a flow of a fluid therethrough. The first chamber is configured to hold a gas generated by the gas generator. The chamber includes a diaphragm deformable in response to an increase in an amount of the gas in the first chamber received by the gas generator. A deformation of the diaphragm in response to the increase in the amount of the gas in the first chamber inhibits flow of the fluid through the passage. 
     The present invention provides, in a second aspect, a method for controlling flow of a fluid which includes providing a passage for conveying a flow of the fluid therethrough. A gas is generated by a gas generator and is received in a first chamber having a diaphragm. The diaphragm is deformed in response to an increase in the amount of the gas in the first chamber such that deformation of the diaphragm restricts or inhibits flow of the fluid through the passage. 
     The present invention provides, in a third aspect, a fluid supply system which includes a fluid source in fluid communication with a first valve and a second valve. The first valve includes a gas generator, a first passage and a first chamber. The gas generator is coupled to the first chamber. The first passage is configured to convey a flow of fluid from the fluid source therethrough. The first chamber is configured to hold a gas generated by the gas generator. The first chamber includes a flexible member deformable in response to an increase in the amount of the gas in the first chamber received from the gas generator, wherein a deformation of the flexible member in response to the increase in the amount of the gas in the first chamber inhibits flow of the fluid through the first passage. The second valve includes a second gas generator coupled to a second chamber. The second passage of the second valve is configured to convey a flow of the fluid from the fluid source therethrough. The second chamber is configured to hold a second gas generated by the second gas generator. The second chamber includes a second flexible member deformable in response to an increase in the amount of the second gas in the second chamber received from the second gas generator, wherein a deformation of the second flexible member in response to the increase in the amount of the second gas in the second chamber inhibits flow of the fluid through the second passage. 
     The present invention provides, in a fourth aspect, a method for controlling a flow of fluid which includes coupling a fluid source with a first valve and a second valve. The first valve includes a gas generator coupled to a first chamber and a first passage for conveying a flow of the fluid from the fluid source therethrough. The first chamber is configured to hold a gas generated by the gas generator. The first chamber includes a flexible member deformable in response to an increase in an amount of the gas in the first chamber received from the gas generator, wherein a deformation of the flexible member in response to the increase in the amount of the gas in the first chamber inhibits flow of the fluid through the first passage. The second valve includes a second gas generator coupled to a second chamber and a second passage for conveying a flow of the fluid from the fluid source therethrough. The second chamber is configured to hold a second gas generated by the second gas generator. The second chamber includes a second flexible member deformable in response to an increase in an amount of the second gas and the second chamber received from the second gas generator, wherein a deformation of the second flexible member in response to the increase in the amount of the second gas in the second chamber inhibits flow of the fluid through the second passage. A flow of a fluid from the fluid source past at least one of the first valve and the second valve is controlled by generating a gas by at least one of the generator and the second generator. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS  
       The subject matter which is regarded as the invention is particularly pointed out and distinctly claimed in the claims at the conclusion of the specification. The foregoing and other objects, features, and advantages of the invention will be apparent from the following detailed description of preferred embodiments taken in conjunction with the accompanying drawings in which: 
         FIG. 1  is a side cross-sectional view of an electrochemical actuator system in accordance with the present invention; 
         FIG. 2  is a perspective cross-sectional view of a second electrochemical actuator system in accordance with the present invention; 
         FIG. 3  is an exploded perspective view of the actuator system of  FIG. 2 ; 
         FIG. 4  is a side cross-sectional view of the actuator system of  FIG. 2 ; 
         FIG. 5  is a perspective cross-sectional view of another electrochemical actuator system in accordance with the present invention; 
         FIG. 6  is an exploded perspective view of the actuator system of  FIG. 5 ; 
         FIG. 6A  is a side cross-sectional view of another embodiment of an electrochemical actuator system in accordance with the present invention; 
         FIG. 7  is a perspective cross-sectional view of a heat switch in accordance with the present invention; 
         FIG. 8  is a perspective cross-sectional view of another embodiment of a heat switch in accordance with the present invention; 
         FIG. 9  is perspective cross-sectional view of a valve system in accordance with the present invention; 
         FIG. 10  is an exploded perspective view of the valve system of  FIG. 9 ; and 
         FIG. 11  is a schematic view of a O 2  pumping operation performed relative to the membrane electrode assembly of  FIG. 1 ; and 
         FIG. 12  is a schematic view of a H 2  pumping operation performed relative to the membrane electrode assembly of  FIG. 1 . 
     
    
    
     DETAILED DESCRIPTION OF AN ILLUSTRATIVE EMBODIMENT  
     In accordance with the principles of the present invention, electrochemical actuator systems for providing actuation force for valves, heat removal, pilot pressure source and restrictions are provided. Such systems are particularly useful in size sensitive actuation applications. 
     In an exemplary embodiment depicted in  FIG. 1 , an electrochemical actuator system  10  includes a membrane electrode assembly  20  having a protonically conductive (or proton-exchange) membrane  40  with catalyst coatings in intimate contact with its major surfaces and which is disposed between a first electrode, such as an anode side diffusion layer structure  30 , and a second electrode, such as a cathode side diffusion layer structure  50 . Protonically conductive membrane  40  is electronically non-conductive and, for example, may be formed of NAFION®, a registered trademark of E.I. Dupont de Nemours and Company, which is based on a polyperflourosulfonic acid and is available in a variety of thicknesses and equivalent weights. The membrane is typically coated on each of its major surfaces with an electrocatalyst such as platinum or a platinum/iridium mixture or alloyed particles (e.g., Pt, or PtIr, or PtIrOx). Alternatively, the electrocatalyst may be disposed on the anode side diffusion layer or the cathode side diffusion layer, and then placed in intimate contact with the protonically conductive membrane during the assembly process. One face of membrane  40  is an anode face or anode aspect, which abuts anode side diffusion layer structure  30 . The opposing face of membrane  40  is on the cathode side and is herein referred to as the cathode face or the cathode aspect, which abuts cathode side diffusion layer structure  50 , for example. The descriptions above of anode faces and aspects along with cathode faces and aspects refer to anodes and cathodes during a gas creation phase (e.g., during electrolysis). 
     Anode side diffusion layer structure  30  and cathode side diffusion layer structure  50  may be formed of materials known to those skilled in the art, including but not limited to carbon paper, carbon cloth, silicon, ceramics, metallic substances, and/or microporous plastics. The diffusion layer structures must be electrically conductive, and various additives or coatings may be added or applied to achieve desired properties. Anode side diffusion layer structure  30 , cathode side diffusion layer structure  50 , and membrane  40  may be bonded (e.g., laminated) together by applying heat and pressure to anode side diffusion layer structure  30  and/or cathode side diffusion layer structure  50  via heat pressing or heat rolling. 
     Membrane electrode assembly  20  may be received between a first current collector or compression plate  60  and a second current collector or compression plate  70 . A first gas seal  35  (e.g., an O-ring) extends around a perimeter of anode side diffusion layer structure  30 , is located between membrane  40  and first compression plate  60 , and is configured to inhibit a movement of gas past seal  35  toward the surrounding ambient environment. A second gas seal  45  (e.g., an O-ring) extends around a perimeter of cathode side diffusion layer structure  50 , is located between membrane  40  and second compression plate  70 , and is configured to inhibit a movement of gas past seal  45  toward the surrounding ambient environment. A water seal  55  extends around a circumference of membrane  40  and is configured to inhibit movement of water past seal  55  toward the surrounding ambient environment. Also, first gas seal  35  may also inhibit movement of water toward the surrounding ambient environment such that the mating of first gas seal  35  and water seal  55  may provide a seal to inhibit movement of water toward the surrounding ambient environment. Further, first gas seal  35  could also be low in water permeability to inhibit the transfer of water past first gas seal  35 . In a further example, water seal  55  and gas seal  35  could be replaced by a single seal which extends around a circumference of membrane  40  and between first compression plate  60  and second compression plate  70 . 
     Returning to  FIG. 1 , water seal  55  inhibits drying of system  10  by inhibiting membrane  40  from being exposed to ambient conditions. Typically, in the prior art the edge of a membrane (e.g., membrane  40 ) in an electrochemical cell (e.g., a membrane electrode assembly sandwiched between two compression plates) would be sandwiched between two seals or gaskets to prevent gas leaks from either side of the membrane with an edge of the membrane extending outwardly beyond the seals. The membrane (e.g., formed of NAFION) often moves water very effectively therein such that it may move water from within the sealed portion of the cell (i.e., behind the seals holding the membrane) to an area of the membrane outside the seals and thereby exposed to the ambient environment if the partial pressure of water is less in the area beyond the membrane. Thus, in the prior art, the extension of a membrane past the seals of an electrochemical cell (e.g., a membrane electrode assembly sandwiched between two compression plates) allows the drying out of such cell by movement of water via the membrane from an interior portion of such a cell to an exterior portion thereof. Water seal  55  and gas seal  35  solve the problem of the transport of water via such a membrane to an exterior of an electrochemical cell by inhibiting movement of water and thereby maintaining a desired moisture or water level within system  10 . For example, water will only migrate via membrane  40  to a cavity between second gas seal  45  and water seal  55  until the cavity has a partial pressure similar to the remainder of system  10 . The water is thus maintained in system  10  for reuse in electrolysis as described below. For example, second gas seal  45  and water seal  55  may be two O-rings with an edge of a membrane lying in a cavity between the two O-rings. Further, second gas seal  45  and water seal  55  may be separate relative to each other, connected to each other or monolithically formed together. Also, second gas seal  45  and water seal  55  may be two sealing bumps on a single piece (i.e., monolithic) seal instead of being two separate seals. 
     First compression plate  60  and second compression plate  70  include passages  65  to allow gas generated by a gas generator, such as membrane electrode assembly  20 , to pass therethrough. For example, such a gas may be generated by applying an electric current to the electrodes (e.g., first electrode  30  and second electrode  50 ) of the membrane electrode assembly to electrolyze water present on MEA  20  thereby forming hydrogen and oxygen gas on opposite sides of the membrane which may pass through passages  65  in each compression plate (i.e., compression plates  60  and  70 ). A cap plate  100  may be connected to, or monolithic relative to, compression plate  60  and may be an outermost portion of system  10 . A gas storage cavity  110  may receive gas generated by the membrane electrode assembly (e.g., by electrolysis). Cavity  110  may be bounded and defined by interior surfaces  115  of plate  100  and an outside surface  62  of compression plate  60 . A seal  120  (e.g., an O-ring) may be received in a cavity  122  of cap plate  100  and may inhibit movement of gas (e.g., hydrogen or oxygen) from cavity  110  toward the surrounding ambient environment. 
     Interior surfaces  137  of an actuation chamber plate  130  and an outside surface  72  of compression plate  70  may bound and define a gas storage chamber  142  receiving a diaphragm  140 . An interior  145  of diaphragm may receive gas (e.g., hydrogen or oxygen) generated by membrane electrode assembly  20  (e.g., by electrolysis). A seal  135  (e.g., an O-ring) between diaphragm  140  and compression plate  70  held in a groove  136  of actuation chamber plate  130  may inhibit movement of gas (e.g., hydrogen or oxygen) and/or water toward the surrounding ambient environment. As described above, it is important to retain water within an electrochemical cell (e.g., MEA  20 , compression plate  60 , and compression plate  70 ) since such water is required for electrolysis and promotes conductivity on the membrane of the MEA. For example, loss of water in small electrochemical cells is one of the main failure modes thereof. It is also important to retain gases when such gases are stored in storage chambers. Preferably, diaphragm materials and seal material are low in O 2 , H 2 , and water permeability are utilized to prevent the loss of water and gases from an electrochemical cell. 
     Diaphragm  140  may be flexible and movable within gas storage chamber  142  in response to a change in an amount of gas in interior  145 . Actuation chamber plate  130  may include an opening  132  through which diaphragm  140  may extend in response to increase in an amount of gas in interior  145 , and the corresponding increase in pressure. The increase in pressure behind diaphragm  140  caused by the increase in the amount of gas in the interior may move the diaphragm and thereby an actuating member, such as a plunger  150 , piston or other component for providing mechanical action or motion. Also, a decrease in the amount of gas, and the accompanying gas pressure, in interior  145  may cause diaphragm  140  to retract or move toward compression plate  70 , e.g. through opening  132 . Such a retraction of the diaphragm may be aided by a spring or other resilient member coupled to the diaphragm or an actuating member driven by the diaphragm. The diaphragm itself could also be resilient. For example, such a decrease in size of diaphragm  140  may be caused or allowed by a recombination of hydrogen from interior  145  and oxygen from gas storage chamber  110  to form water on membrane  40  by reverse electrolysis (i.e., by reversing the current flow direction). For example, the decrease in the amount of gases in interior  145  may decrease the size of the diaphragm to cause a retraction of plunger  150  driven by the diaphragm. Such a retraction of the plunger could also cause the plunger to be at least partially received within gas storage chamber  142 . 
     As described above, applying a voltage to Membrane electrode assembly  20  saturated with water causes electrolysis to electrochemically convert water into H 2  gas and O 2  gas as depicted below: 
     Net: Electrolysis &amp; Recombination: 
     
         
         2 H 2 O(liquid) 0 2  (gas)+2 H 2  (gas)
 
Thus, two 2 moles of liquid water produce 2 moles of H 2  and  1  mole of O 2  and there is a 3/2 molar ratio between the gases produced and the liquid water required. The O 2  and H 2  gas produced on either side of membrane  40  (e.g., a NAFION membrane) may be used to extend plungers (e.g., plunger  150 ), pistons or other actuating members to create motion (e.g., linear motion). Also, one of the gases may be utilized to create such motion while the other gas is expelled or stored for later recombination. The gases may be recombined to form water to remove pressure or retract the plungers, pistons or other actuating members. For example, at a constant pressure of 1 ATM, 1 cc of liquid water will produce 2050 cc of gas (683 cc O 2  &amp; 1367 cc of H 2 ). The ratio of O 2  and H 2  produced from the liquid water is directly proportional to the current supplied to the membrane. Likewise, the rate of recombination of the gases back to water is also directly proportional to current across the membrane. Controlling current is therefore an easy and effective way to control the pressure, and amount of gas, in interior  145 . Further, the relatively large gas volume to liquid volume ratio (e.g., 1 cc of liquid water will produce 2050 cc of gas) for the electrolysis process described above enables a system, such as system  10 , utilizing such plungers, pistons or other actuating members driven by the changes in gas pressure to develop relatively large strains and pressures.
 
       
    
     In order to repeatedly utilize an electrochemical actuator system, such as system  10 , the process of electrolysis and reverse electrolysis must be repeatable. This requires that the proportions of hydrogen to oxygen produced during electrolysis be maintained in storage in proportion such that may they be recombined as desired to form water. However, in the case of leakage of oxygen or hydrogen from the chamber(s) (e.g., chamber  110  or chamber  142 ), it would not be possible to completely retract or otherwise disengage an actuating member (e.g., plunger  150 ) driven by a diaphragm (e.g., diaphragm  140 ), because enough of one of the elements (e.g., oxygen or hydrogen) may not be present to recombine the elements into water and thereby reduce the amount, and corresponding pressure, of each element in the chambers. For example, if H 2  gas permeated and leaked out of the appropriate storage chamber at a rate higher than the O 2  did from the other storage chamber, a recombination of the gases stored in the chambers back to water would result in a residual amount of O 2  left over thereby preventing a diaphragm (e.g., diaphragm  140 ) driving an actuating member from fully retracting. Further, in another example, permeation of inert gases into one or both of the chambers holding the gases could create a portion of inactive gas, which could also prevent the diaphragm from fully retracting due to its continued presence in the expandable diaphragm (e.g., diaphragm  140 ). 
     In an example, seal  120  between cap plate  100  and compression plate  60  may be configured to allow a gas (e.g., oxygen or hydrogen) to pass to the surrounding ambient environment when a particular pressure is reached in storage cavity  110  of cap plate  100 . Because the proportion of gas in each of these chambers may deviate (e.g., by permeation) from the 1/2 ratio of O 2  to H 2  described above, the chamber(s) may be configured (e.g., using seal  120 ) to allow gas to escape when pressure therein reaches a predefined amount. By allowing a chamber, such as cavity  110 , to leak above a typical working pressure, but prior to a mechanical failure of the chamber or the seal, the proper proportions of the gases may be restored. Water may be electrolyzed to provide gas to the respective storage chambers (e.g., storage chamber  110  and diaphragm  140  in chamber  142 ) for oxygen and hydrogen. For example, in the case of a hydrogen storage chamber lacking an appropriate amount of hydrogen for full combination with O 2  in an Oxygen storage chamber, O 2  and H 2  may be provided to the appropriate chambers by electrolysis. Some of the O 2  gas may leak past a seal (e.g., seal  120 ) in the Oxygen storage chamber (e.g., chamber  110 ) at pressures above a predefined leakage pressure while the H 2  gas would be retained in the appropriate chamber (e.g., chamber  142 ) as the excess O 2  gas is purged past the seal. The added flow (e.g., of O 2 ) or purging (e.g., past seal  120 ) may also purge out inert gases that may have migrated into the chamber (e.g., chamber  110 ). 
     Thus, the “overfilled” gas (e.g. oxygen) in the example described would leak past seal  120  when pressure in storage cavity  110  reached a leakage pressure thereby allowing hydrogen to continue to be generated such that the 1/2 desired ratio in the storage chambers may be recovered. Thus, the production of gases would eventually result in the desired ratio as O 2  and H 2  is continuously provided to the chambers and excess O 2  leaks out past the seal at the predefined pressure. The recovery of this ratio allows a diaphragm (e.g., diaphragm  140 ) and any actuating member driven thereby to be retracted to a start position because the gases may now be fully recombined into water. As depicted in  FIG. 1 , seal  120  could be an O-ring in groove  122  or it could be any other type of seal configured to inhibit movement of gas up to a particular pressure. Further, seal  135  could similarly provide a pressure relief function similar to that of seal  120 . 
     For example, the chambers (e.g., chambers  110  and  142 ) of an electrochemical actuator system (e.g., system  10 ) may be sized exactly twice as large for H 2  storage as for O 2  storage and valves (not shown) or seals (e.g., seal  120 ) may be incorporated that enable both chambers to leak gas above 1000 PSI. The restoration of a desired gas balance (i.e., the 1/2 ratio described) could be performed at any time. If excess O 2  remained in an O 2  chamber (e.g., chamber  110 ), the O 2  chamber would leak sooner than an H 2  chamber (e.g., chamber  142 ) during a purge (i.e., via electrolysis), but such a purge would eventually cause each gas to leak past such valves or seals leaving 1000 PSI of each remaining in the appropriate chamber. Since the volume of the H 2  chamber would be twice the volume of the O 2  chamber, a perfect ratio would be provided to allow the recombination of the gases to form water and fully retract a diaphragm and driven actuating member. Although such a perfect ratio is theoretically possible, it is rarely needed so it is within the scope of this invention to restore a close ratio or ratio needed to obtain functional actuating members. 
     Further, such seals (e.g., seal  120 ) configured to leak at a desired pressure may also prevent damage to the storage chambers (e.g., chamber  110  or chamber  142 ) and system (e.g., system  10 ) as a whole. For example, if H 2  was used for actuation (i.e., driving a plunger, piston or other actuating member) and O 2  was stored and there was a continuous loss of H 2  due to diffusion or otherwise due to the operation of the system over the course of time, O 2  pressure would continually rise as an out of proportion amount of O 2  was supplied to the O 2  storage chamber until system  10  was mechanically damaged from the excessive pressure, absent a pressure relief mechanism, such as a seal (e.g., seal  120 ). Seal  120  (e.g., an O-ring) may thus be selected and installed such that it would leak beyond a certain leakage pressure (e.g., 1000 PSI), which would be prior to mechanical damage and higher than that required to contain the necessary gas(es) of recombination. The difference between the two pressures (i.e., a leakage pressure to allow gas to escape and a damaging pressure that would cause damage to the seal and/or system  10 ) is often many multiples apart. 
     An electrochemical cell (e.g., a membrane electrode assembly held between two compression plates) must be held under compression to manage the electrical losses between all of the interfacing layers in such a cell or cell assembly. The components that provide this compressive force are typically referred to as the cell clamping. The clamping required for an electrochemical actuator system (e.g., system  10 ) may be achieved by overmolding the system together as a unit or overmolding portions of the system (e.g., MEA  20 , compression plate  60 , and compression plate  70 ) together using plastic in an injection molding process. Conventionally, electrochemical cells have mechanical fasteners or other mechanical means to hold them in compression. By using injection molding over other clamping methods fewer parts are required and accommodations may be made relative to variations in cell component thickness. For example, system  10  may be compressed by a closing of a mold in an injection molding machine where it would have a layer of plastic applied to enough of an outside surface thereof to hold system  10  together under compression after the plastic applied has cured. In another example, the compression of system  10  in such an injection molding machine may be performed after the closing of a mold by a compression mechanism which causes the mold to compress system  10  via a threaded rod and adjustment nut or other mechanism providing such compression. 
     In a typical prior art electrochemical cell, a spring accommodates a relaxation of the membrane electrode assembly (MEA) to maintain the cell under compression. Absent such a spring, as the MEA relaxed there would be a significant fall off of cell compression leading to very high resistive losses. In one example, an electrochemical actuator system (e.g., system  10 ) is preloaded with a force to provide adequate sealing and compression of the MEA at the same time. A seal (e.g., seal  120 ) above a compression plate (e.g., compression plate  60 ) thereof provides resilience and acts as a spring would in the prior art device by maintaining the system under compression. As the MEA (e.g., MEA  20 ) relaxes, the seal (e.g., seal  120 ) expands due to the lessening of pressure thereon to maintain the pressure desired in the MEA. This is possible for small gas generation cells and actuation systems due to the very high linear gasket length of the seal (e.g., seal  120 ) relative the cell active area. Also, the sealing effectiveness of the seal (e.g., seal  120 ) would not be compromised because the deflection of the seal during compression is significantly more than the amount of relaxation of the MEA. For instance, if the seal deflected 0.010″ during compression and the MEA only relaxed 0.002″ over the life of the system (e.g., system  10 ) there would be very little effect on the seal effectiveness over the life of the cell. 
     Also, to allow flexibility of design of electrochemical actuator systems, such as system  10 , various gases can be used as a working fluid to drive a diaphragm (e.g., diaphragm  140 ). For example, H 2  and O 2  can be created by electrolyzing water as described above and one or both of the gases may drive the diaphragm while the other may be stored in a storage chamber. In a configuration shown in  FIG. 6  one side of a cell is exposed to ambient air. In this configuration O 2  from the air is pumped across the membrane causing O 2  pressure behind the diaphragm. Such O 2  pumping is defined herein as the consumption of O 2  on one side of a membrane and a generation of O 2  on the other side of such a membrane as depicted in  FIG. 11 . For example, on a first side of a membrane open to the ambient air or a low pressure source of oxygen, oxygen may be combined with electrons and hydrogen ions to form water as depicted in the following formula: 
       O 2 +4H + +4e 2H 2 O 
     On a second side of the membrane oxygen is generated via the following formula in which water is electrolyzed to form hydrogen ions and oxygen: 
       2H 2   4H ++ 4e+O 2    
     In this manner, O 2  from the air may be pumped across a membrane to cause O 2  pressure behind a diaphragm to actuate an actuating member or mechanical device, for example. Such O 2  pumping may occur at a voltage of about 0.5 to 1.3 volts, for example. H 2  may also be utilized to drive a diaphragm while oxygen may be stored in a storage chamber. H 2  or O 2  may be pumped back and forth across the membrane by itself without using a second gas by applying electrical energy (e.g., direct current) to the membrane electrode assembly. 
     H 2  pumping as defined herein is depicted in  FIG. 12  in which low pressure hydrogen is subjected to a voltage (e.g., 0.05-0.2 volts) to split the H 2  into hydrogen ions and electrons as depicted in the following formula: 
       2H 2   4H + +4e 
     On an opposite of the membrane, hydrogen ions and electrons are formed as hydrogen (e.g., under pressure) as described in the following formula: 
       4H + +4ē 2H 2    
     As described above, permeation can cause the amount of gases held in storage chambers (e.g., chamber  110  or chamber  142 ) of electrochemical actuator systems (e.g., system  10 ) to be uncertain. Also, It may be difficult to know an amount of gas on a pumped/high pressure side of an electrochemical cell or system due to diffusion of gases across the membrane. It is desirable to know the state of an actuating member, such as the position of a diaphragm or actuating member driven thereby. It is also helpful to know when an active gas is depleted and the actuating member is fully retracted. Knowing this condition (i.e., the point at which a diaphragm and driven actuating member is fully retracted) would create a starting-over point after an unknown amount of diffusion occurred or after a long shutdown. A method of determining a point of full retraction of such a diaphragm or actuating member includes applying a voltage that would normally pump a gas (e.g., O 2  as described above) across a membrane and watching the fall-off of current via a current monitor (not shown). When the gas (e.g., O 2 ) that is being pumped is depleted the current will fade to a very low number. For example, if O 2  was used as a working fluid then a zero state of O 2  in an O 2  storage cavity may be found by applying 1.3 volts to pump the O 2  from the cavity until it is depleted. When the current approaches zero it is reasonable to assume that no O 2  remains in the cavity. The process may then be reversed and it would be possible to keep track of the O 2  quantity made by measuring the amount of electrical current per unit time (i.e., coulombs), via a current sensor (not shown). This method may be utilized to provide an estimate of the state of an actuating member prior to re-use thereof, or at any time to see how far off a calculated state of O 2  compares to the actual state of O 2 . Also, these calibrations may be used to establish a regularly calibrated O 2  leak rate. In this way forecasts for a system (e.g., system  10 ) may be made on actual measurements. Although O 2  is described above as the working fluid, H 2  and H 2 /O 2  may also be used in such a method with voltages different from that for O 2 , for example. 
     As described above, a membrane (e.g., membrane  40 ) may allow water to move within an electrochemical actuator system (e.g., system  10 ). Water diffuses through the membrane allowing a water source to be on either side of a membrane electrode assembly (e.g., membrane electrode assembly  20 ). As described above, it is important to maintain the water within such a system (e.g., system  10 ) to prevent drying out of the membrane to ensure adequate conductivity and to allow sufficient water for electrolysis. Water is placed in a particular location at the start up of a system and when additional water is desired, e.g., on leakage of water from the system. Such water may be placed between a diaphragm (e.g., diaphragm  140 ) and a chamber receiving such diaphragm. For example, water may be received in interior  145  of diaphragm  140 . As described, interior  145  may receive gas generated by membrane electrode assembly  20  and since interior  145  receives the gas from the membrane electrode assembly, there will be sufficient water available to create such gas via electrolysis. For example, as the amount of gas in interior  145  decreases during recombination (i.e., reverse electrolysis) process, the amount of water therein will increase with the water taking up less space than the gas which the water replaces. 
     As described above, it may be desirable to utilize oxygen as a working fluid in an electrochemical actuator system. However, it is not desirable to provide oxygen to electrochemical actuating member during assembly thereof such that only O 2  was held therein due to difficulties in providing the oxygen into a storage chamber of such a system during assembly or soon thereafter. However, such oxygen may be supplied to an electrochemical actuator system for use as a working fluid by creating both O 2  and H 2  using electrolysis and taking advantage of the fact that there is twice as much H 2  consumed during recombination (i.e., reverse electrolysis). In one example, two gas holding chambers for receiving gas generated by an MEA may be provided of equal size. Such chambers may both be configured to leak at a certain leak pressure. Water may be electrolyzed until both gases in the corresponding chambers reach the leak pressure. At the leak pressure, each full chamber would contain an equal amount of gas despite twice as much hydrogen being generated, i.e. the remainder of the hydrogen would leak out at the leak pressure. The electrical current may then be reversed to recombine the oxygen and hydrogen, but the H 2  will be fully consumed and only half of the O 2  would be used. The O 2  remaining may then be utilized as a working fluid, i.e. pumped back and forth across a membrane. 
     In another example,  FIGS. 2-4  depict an electrochemical actuator system  200  similar to system  10  except that system  200  includes two oppositely disposed actuating members in contrast to plunger  150  and storage chamber  110  ( FIG. 1 ). In particular, system  200  includes a membrane electrode assembly  220  having a protonically conductive membrane  240 . Membrane electrode assembly  220  may be received between a first current collector or compression plate  260  and a second current collector or compression plate  270 . First compression plate  260  and second compression plate  270  include passages  265  to allow gas generated by membrane electrode assembly  220  (e.g., via electrolysis) to pass therethrough. An actuation chamber plate  300  may be connected to compression plate  260 . A gas storage chamber  342 , similar to_gas storage chamber  142 , may be defined by interior surfaces of actuation chamber plate  300  and may receive gas generated by the membrane electrode assembly (e.g., by electrolysis) along with receiving a diaphragm  341 . An interior  310  of diaphragm  341  similar to interior  145  may receive a gas (e.g., hydrogen or oxygen) generated by membrane electrode assembly  320  (e.g., by electrolysis). A seal  335  between diaphragm  341  and compression plate  360  may inhibit movement of gas (e.g., hydrogen or oxygen) and/or water toward the surrounding ambient environment. Diaphragm  341  may be flexible and movable in response to a change in an amount of gas in interior  310 . Actuation chamber plate  300  may include an opening  333  through which diaphragm  341  may extend in response to increase in an amount of gas in the interior, and the corresponding increase in pressure. The increase in pressure behind diaphragm  341  caused by the increase in the amount of gas in the interior may move the diaphragm and thereby an actuating members, such as a plunger  350 , piston or other actuating members. Also, a decrease in the amount of gas, and the accompanying gas pressure, in interior  310  may cause diaphragm  341  to retract or move toward compression plate  260 , e.g. through opening  333 . Plunger  351  may be held (e.g., provided circumferential or perimeter support) by a plunger support plate  401 . Also, the plunger may extend into and out of gas storage chamber  342  as diaphragm  341  expands and retracts. 
     Similarly, an actuation chamber plate  330  may be connected to compression plate  270 . A gas storage chamber  345 , similar to gas storage chamber  142 , may be defined by interior surfaces of actuation chamber plate  330  and may receive gas generated by the membrane electrode assembly (e.g., by electrolysis) along with receiving a diaphragm  340 . An interior  311  of diaphragm  340 , similar to interior  145 , may receive gas (e.g., hydrogen or oxygen) generated by membrane electrode assembly  220  (e.g., by electrolysis). A seal  355  between diaphragm  340  and compression plate  370  may inhibit movement of gas (e.g., hydrogen or oxygen) and/or water toward the surrounding ambient environment. Diaphragm  340  may be flexible and movable in response to a change in an amount of gas in the interior thereof. Actuation chamber plate  330  may include an opening  334  through which diaphragm  340  may extend in response to increase in an amount of gas in interior  311 , and the corresponding increase in pressure. The increase in pressure behind diaphragm  340  caused by the increase in the amount of gas in the interior may move the diaphragm and thereby an actuating members, such as a plunger  350 , piston or other actuating members. Also, a decrease in the amount of gas, and the accompanying gas pressure, in the interior may cause diaphragm  340  to retract or move toward compression plate  270 , e.g. through opening  334 . Plunger  350  may be held (e.g., provided circumferential or perimeter support) by a plunger support plate  402 . Also, plunger  350  may extend into and out of gas storage chamber  345  as diaphragm  340  extends and retracts. 
     Plunger  350  and plunger  351  may be moved in opposite directions in response to the amounts of gas provided by the MEA (e.g., via electrolysis) behind the diaphragms (i.e., diaphragm  340  and diaphragm  341 ) to drive the plungers (i.e., plunger  350  and plunger  351 ). The plungers may be used to provide linear motion, activate or deactivate switches or other mechanical action. 
     In another example depicted in  FIGS. 5-6 , an electrochemical actuator system  400  is similar to system  200  except that system  400  includes a diaphragm  440  and plunger  450  on a first side of a membrane electrode assembly  420  while on an opposite side of the membrane electrode assembly, system  400  is open to the surrounding ambient environment. An actuation chamber plate  430  may be connected to compression plate  470 . A gas storage chamber  442 , similar to gas storage chambers  142  and  342 , may be defined by interior surfaces of actuation chamber plate  430  and may receive gas generated by the membrane electrode assembly (e.g., by electrolysis) along with receiving a diaphragm  440 . An interior  445  of diaphragm  440 , similar to interior  145 , may receive gas (e.g., hydrogen or oxygen) generated by membrane electrode assembly  420  (e.g., by electrolysis). A seal  435  between diaphragm  440  and compression plate  470  may inhibit movement of gas (e.g., hydrogen or oxygen) and/or water toward the surrounding ambient environment. Diaphragm  440  may be flexible and movable in response to a change in an amount of gas in interior  445 . Actuation chamber plate  430  may include an opening  434  through which diaphragm  340  may extend in response to increase in an amount of gas in interior  445 , and the corresponding increase in pressure. The increase in pressure behind diaphragm  440  caused by the increase in the amount of gas in the interior may move the diaphragm and thereby an actuating members, such as a plunger  450 , piston or other actuating members. Also, a decrease in the amount of gas, and the accompanying gas pressure, in the interior may cause diaphragm  440  to retract or move toward compression plate  470 , e.g. through opening  434 . Plunger  450  may be held (e.g., provided circumferential or perimeter support) by a plunger support plate  500 . As indicated, the membrane electrode assembly may be open to the surrounding ambient environment via openings or passages  465  in compression plate  460  allowing oxygen to be drawn directly from the surrounding ambient environment for recombination of oxygen and hydrogen (e.g. stored in interior  445  and used as a working fluid to drive plunger  450 ). Upon electrolysis to provide hydrogen to interior  445 , oxygen is expelled to the surrounding ambient environment from which it can be reclaimed when desired for recombination of the stored hydrogen and such oxygen into water on MEA  420 . The use of the surrounding ambient environment as an oxygen source allows system  400  to be smaller than if the oxygen was stored in a storage chamber of system  400 . Plunger  450  may be used to provide linear motion, activate or deactivate switches or other mechanical motion or force. 
     In another example depicted in  FIG. 6A , an electrochemical actuator system  1300  is similar to electrochemical actuator system  10  (including identical reference numerals referring to identical parts) except that system  1300  includes a seal  1035  in groove  136  and located between diaphragm  140  and actuation chamber plate  130  instead being located between diaphragm  140  and compression plate  70  as is seal  135  ( FIG. 1 ). Seal  1035  may inhibit movement of gas (e.g., hydrogen or oxygen) and/or water toward the surrounding ambient environment as does seal  135 . 
     The location of seal  1035  on an opposite side of diaphragm  140  allows seal  1035  to the located away from, and avoid contact with, the working fluid (e.g., hydrogen, oxygen) and/or water located in storage chamber  142 . As indicated above, diaphragm materials that are low in O 2 , H 2 , and water permeability are preferable. Also, the seals should be formed of material configured to retain the gases (e.g., hydrogen, oxygen) generated and/or water. The materials typically used for sealing are very elastic and may be high in permeability. As described, seal  1035  is placed on an opposite side of membrane  140  relative to storage chamber  142  and thus is outside the wetted area. Seal  1035  thus may retain a desired sealing function by having the seal press on the diaphragm from an opposite side thereof relative to seal  135 . Such a location of the seal allows the diaphragm to make the actual seal eliminating exposure of the seal to the working fluids (e.g., oxygen, hydrogen and/or water). For such a seal (e.g., seal  1035 ) to be effective the seal must be relatively thick and compliant to make up for any surfaces that may be out of flatness. By placing the seal behind the diaphragm the seal still performs this needed function (i.e., making up for any surfaces out of flatness) but is not exposed to the working fluid(s). Further, utilizing the arrangement depicted in  FIG. 6A , the material forming the diaphragm (e.g., diaphragm  140 ) may be optimized for its function free of the seal material requirements, such as compression stress relaxation, and the seal material can be optimized for its function free of the diaphragm requirements such as gas permeability and MEA material compatibility. 
       FIG. 7  depicts a heat switch system  600  similar to system  400  except that plunger  450  is replaced by a plunger  650  which drives a heat switch  655 . An actuation chamber plate  630  may be connected to compression plate  670 . A gas storage chamber  642 , similar to gas storage chambers  142  and  342 , may be defined by inner surfaces of actuation chamber plate  630  and may receive gas generated by a membrane electrode assembly  620  (e.g., by electrolysis or by O 2  pumping, i.e., extracting pure O 2  from air and forming O 2  on an opposite side of the membrane) along with receiving a diaphragm  640 . An interior  645  of diaphragm  640  and storage chamber  642 , similar to interior  145 , may receive gas (e.g., hydrogen or oxygen) generated by membrane electrode assembly  620  (e.g., by electrolysis or O 2  pumping). A seal (not shown) between diaphragm  640  and compression plate  670  may inhibit movement of gas (e.g., hydrogen or oxygen) and/or water toward the surrounding ambient environment. Diaphragm  640  may be flexible and movable in response to a change in an amount of gas in interior  645 . Actuation chamber plate  630  may include an opening  634  through which diaphragm  640  may extend in response to increase in an amount of gas in interior  645 , and the corresponding increase in pressure. The movement of diaphragm  640  caused by the increase in the amount of gas in the interior may move plunger  650 . Also, a decrease in the amount of gas, and the accompanying gas pressure, in the interior may cause diaphragm  640  to retract or move toward membrane electrode assembly  620 , e.g. through opening  634 . Plunger  650  may be held (e.g., provided circumferential or perimeter support) by a plunger support plate  700 . Also, plunger  650  may extend through opening  634  in response to the extension or retraction of diaphragm  640 . Compression plate  660  may be open to the surrounding ambient environment via passages  665  allowing oxygen to be drawn directly from the surrounding ambient environment for recombination of oxygen and hydrogen (e.g. stored in interior  645  and used as a working fluid to drive plunger  650 ). Upon electrolysis to provide hydrogen to interior  645 , oxygen is expelled to the surrounding ambient environment from which it can be reclaimed when desired for recombination of the stored hydrogen and such oxygen into water on MEA  620 . Also, as indicated above,  02  can be electrochemically pumped across the cell from the ambient to create gas behind the diaphragm in interior  645 . 
     In one example, direct oxidation fuel cells produce water, carbon dioxide and heat as a result of the reactions. This heat can be useful in terms of warming the fuel cell in a cold environment and ensuring that the reactions occur at a rate that is sufficient to generate sufficient power and current to provide power to the application device. However, in other operating circumstances, the heat can build up and result in dehydration of a membrane of such a fuel cell, which in turn results in a loss of efficiency and lower power output of the fuel cell. Thus, the heat generated in the reaction of such a fuel cell is preferably dissipated or transferred by heat switch  655 . 
     More specifically, heat switch  655  contains a first (e.g., “hot”) heat transfer member  710  which, is thermally coupled to a component (e.g., of a fuel cell) requiring temperature control. A second (e.g., “cold”) heat transfer member  720  is placed at a desired distance or a gap  721  from first heat transfer member  710 , and second heat transfer member  720  transfers heat to the ambient environment either directly or indirectly. For example, the second surface may be a portion of a casing or housing, or may be used to transfer heat to a casing or housing of an application device, a fuel cell system or other component. First heat transfer member  710  may include a heat transfer conduit  715  for receiving a heat transfer fluid and second heat transfer member  720  may include a second conduit  725  for receiving a heat transfer fluid. Such conduits may provide the excess heat (e.g. conduit  715 ) and the means (e.g., conduit  725 ) for expelling such excess heat, for example. A bottom contacting surface  723  of first heat transfer member  710  and a top contacting surface  724  of second heat transfer member  720  are separated by gap  721  provided that the temperature has not reached a particular threshold. Gap  721  may be maintained by a resilient member(s), such as a series of elastic beads or wave springs (not shown) therein. The gap is preferably on the order of about  250  microns, but it this will vary depending upon the particular application of the invention. 
     A sensor  711  may determine a temperature of first heat transfer member  71   0 . In response to such temperature, as indicated above, plunger  650  may be driven (e.g., automatically by a controller (not shown) by diaphragm  640  in response to electrolysis of water on MEA  620 . Plunger  650  may move bottom contacting surface  723  toward top contacting surface  724  (e.g., to contact) to reduce the thermally insulating air gap (i.e., gap  721 ) to increase heat transfer therebetween. For example, if first conduit  715  contains heat transfer fluid of excess temperature or otherwise has an elevated temperature, a contact between surface  723  and surface  724  may allow such excess heat to be transferred to second heat transfer member  720  and the heat transfer fluid in second conduit  725 . Such heat may be expelled via the heat transfer fluid in second conduit  725  or directly by second heat transfer member  720 . When the temperature of first heat transfer member  710  has decreased sufficiently (e.g., as determined by sensor  711 ), the electrolysis process may be reversed to recombine oxygen and hydrogen to form water on MEA  620  thereby retracting plunger  650  (e.g., with an assist from the wave springs) and moving first heat transfer member  710  away from second heat transfer member  720 . For example, such reversal electrolysis may be caused by a controller (not shown) coupled to a temperature sensor (e.g., sensor  711 ). The thermally insulating air gap (i.e., gap  721 ) may be varied via a controller and the electrolysis and reverse electrolysis processes described above depending on how much heat transfer is desired between first heat transfer member  710  and second heat transfer member  720  and therefore how much distance is desired between first heat transfer member  710  and second heat transfer member  720 , i.e., gap  721 . 
     Also, in another example, system  600  may be identical to that depicted in  FIG. 7  except that conduit  715  and conduit  725  may include heat conducting members connected to heat transfer members  710  and  720  instead of heat transfer fluids flowing through conduits in heat transfer members  710  and  720 . For example, such heat conducting members may be metal rods which are connected on one end to such heat transfer members and which are immersed in a second end in a heat transfer fluid or a heat sink. 
     In another example depicted in  FIG. 8 , a heat switch system  700  is similar to system  600  (including identical numbering), except that system  700  and includes a cap plate  800  connected to compression plate  660  and may be the outermost portion of system  10 . A gas storage cavity  810  may receive gas generated by the membrane electrode assembly (e.g., by electrolysis). Cavity  810  may be bounded and defined by interior surfaces (not shown and similar to interior surfaces  115 ) of plate  800  and outside surface (not shown and similar to outside surface  62 ) of compression plate  660 . A seal (not shown and similar to seal  120 ) may be received in a cavity (not shown and similar to cavity  122 ) of cap plate  800  and may inhibit movement of gas (e.g., hydrogen or oxygen) from cavity  810  toward the surrounding ambient environment. Thus, in contrast to system  600 , the gases generated by electrolysis are stored in cavity  810  (e.g., oxygen) and interior  645  (e.g., hydrogen). As described above, diaphragm  640  may extend in response to increase in an amount of gas (e.g., hydrogen) in interior  645 , and the corresponding increase in pressure. Such electrolysis may be reversed to retract diaphragm  40  utilizing the gases in cavity  810  and interior  645 . 
     As indicated above, the described and depicted heat switches may be utilized to cool or heat various components within a fuel cell, or other devices which would require cooling or heating and which small size and efficiency of the described heat switches is desired. For example, the heat switches described may be utilized in the applications described in co-owned U.S. patent application Ser. No. 11/021,971 relative to a different type of heat switch. 
       FIGS. 9-10  depict an electrochemically actuated valve system  1000  which includes a cap plate  1100  connected to a compression plate  1060 , and the cap plate may be an outermost portion of system  1000 . A gas storage cavity  1010  may receive gas generated by a membrane electrode assembly  1020  (e.g., by electrolysis) located between compression plate  1060  and compression plate  1070 . Cavity  1010  may be bounded and defined by interior surfaces (not shown and similar to interior surfaces  115 ) of plate  1100  and an outside surface (not shown and similar to outside surface  62 ) of compression plate  1060 . A seal  1035  may be received in a cavity (not shown and similar to cavity  122 ) of cap plate  1100  and may inhibit movement of gas (e.g., hydrogen or oxygen) from cavity  1010  toward the surrounding ambient environment. 
     A diaphragm  1040  is located on an opposite side of the MEA relative to cap plate  1100 . An interior (not shown and similar to interior  145 ) of diaphragm  1040  between diaphragm  1040  and compression plate  1070  may receive a gas (e.g., hydrogen or oxygen) generated by the membrane electrode assembly (e.g., by electrolysis). A seal  1055  between diaphragm  1040  and compression plate  1070  may inhibit movement of a gas (e.g., hydrogen or oxygen) and/or water toward the surrounding ambient environment. Diaphragm  1040  may be flexible and movable in response to a change in an amount of gas in the interior thereof. Actuation chamber plate  1030  may include an a cavity  1034  into which diaphragm  1040  may extend in response to increase in an amount of gas in interior  1045 , and the corresponding increase in pressure. Cavity  1034  may be open to allow gas or liquid flow therethrough along with receiving the diaphragm  1040  as it expands and contracts. As the diaphragm moves into cavity  1034  that has a fluid flowing in it the pressure drop of the fluid changes. In this way the valve is a variable pressure drop valve capable of regulating flow from fully open to fully closed off. Alternatively, a flexible tube (not shown) may be received in cavity  1034  and diaphragm  1040  may act on such a tube to regulate flow through the tube and plate  1030 . In a further example, such a flexible tube may be received in cavity  1034  and diaphragm  1040  may be absent such that gas generated may act directly on such a flexible tube to regulate the flow through such tube. 
     Actuation chamber plate  1030  may also include a conduit  1032  or tube therethrough which may receive a flow of gas or liquid to be controlled or regulated by valve system  1000 . For example, a movement of diaphragm  1040  caused by an increase in the amount of gas in the interior may control a flow of fluid through conduit  1032 . Diaphragm  1040  may be completely cover openings  1033  through plate  1030  to stop flow through plate  1030 . Alternately, diaphragm  1040  may partially cover such openings or just constrict the passage to the opening(s) to selectively regulate flow through plate  1030  at a particular flow level. Diaphragm  1040  may be extended (e.g., via electrolysis) or retracted (e.g., via reverse electrolysis) to regulate (e.g., regulated by a controller) such flow through plate  1030 . As depicted in  FIGS. 9-10 , conduit  1032  may include connecting portions  1036  insertable into openings  1033  to form conduit  1032 . 
     Further, plate  1030  may include any number of tubes or passages that may be regulated (e.g., completely or partially collapsed to regulate flow) by the extension and retraction of diaphragm  1040  driven by gas pressure in the interior of diaphragm  1040 . Further, multiple systems  1000  may regulate the flow of fluid through plate  1030  or multiple plates  1030 . In one example, system  1000  may be utilized to regulate the flow of air to two fuel cells being supplied from a single air source/pump. In such an application multiple systems  1000  may be placed downstream of a point where the air flow splits and extends into multiple branch lines, each of which extends toward a particular fuel cell. Each of systems  1000  in the corresponding branch line may be independently regulated (e.g., extension or retraction of diaphragm  1040  due to electrolysis controlled by a controller) to regulate a flow to each fuel cell. Further, it will be understood that such a system of regulating the flow of air utilizing multiple systems  1000  may be utilized for applications other than fuel cells that require such regulation of air from a single air source or pump. 
     In another example, an electrochemical gas generator system may be used to create and control pilot pressure operated devices (e.g., regulators, valves etc.). Typically pilot pressure controlled devices require a large pump to supply pilot pressure. An electrochemical gas generator (e.g., a membrane electrode assembly compressed between two compression plates, such as membrane electrode assembly  20  compressed between compression plate  60  and compression plate  70  via overmolding) having very accurate control may be substituted for such a pump with the resultant advantages of a very small package to create and control a pilot pressure operated device (e.g., a regulator, valve, or actuating member). Also, the electrochemical cell requires very little voltage and power relative to a prior art pump so the electrochemical cell may be supplied from a small battery. The electrochemical cell may be very compact thereby allowing the electrochemical cell to be built right into the regulator or mounted close to where the pressure is needed. Such electrochemical gas generators operating at a location where a pilot pressure is needed has many benefits over the conventional centralized pump with pneumatic lines running to all the locations needing pressure. These advantages include added mobility, substantial size reduction, lower power consumption, and higher reliability. 
     As described above relative to the figures, an electrochemical cell, including a membrane electrode assembly and compression plates holding such membrane electrode assembly in compression (e.g., by overmolding), may be utilized to generate gas to provide mechanical motion or force to provide actuation for various functions. The gases produced by providing electrical energy to such a membrane electrode assembly may be stored in a storage chamber (e.g., storage chamber  110 ) or provided to an interior (e.g., interior  145 ) of a membrane (e.g., membrane  140 ) which is moveable based on the amount of gas produced by the membrane electrode assembly and received in such an interior. The gases may be recombined to retract such a membrane and form water at the membrane electrode assembly. Methods for purging such gas storage chambers and/or interiors of membranes are also provided to provide repeatability and allow the maintenance of such electrochemical cells providing actuation. Various working fluids (e.g., H 2 , O 2 , may be utilized to control a size of a diaphragm to provide actuation. 
     Further, unlike conventional pneumatic actuating members that require a compressor, electrochemical actuating members as described above are self contained requiring only a small current from a low voltage (e.g., less than 2V) source such as a battery. Since they are sealed and contain their own water, they will require little or no outside gases or liquids to operate. 
     Also, the electrochemical actuating members described require very little hold power (e.g., the power expended to maintain a plunger or actuating member in a particular position) compared to conventional actuation mechanisms such as solenoid actuating members. For example, the only hold power required is to make up for the gas that may diffuse through the membrane or otherwise may leak to the surrounding ambient environment. Such leakage may be limited by utilizing the seals described above. 
     Although preferred embodiments have been depicted and described in detail herein, it will be apparent to those skilled in the relevant art that various modifications, additions, substitutions and the like can be made without departing from the spirit of the invention and these are therefore considered to be within the scope of the invention as defined in the following claims.