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A fuel cell system including an anode chamber having a fuel mixture comprising methanol and water, and a diffusion layer, a fuel source in fluid communication with the anode chamber via a conduit, a cathode chamber having a cathode and a diffusion layer, wherein the diffusion layer is in fluid commu

A fuel cell system including an anode chamber having a fuel mixture comprising methanol and water, and a diffusion layer, a fuel source in fluid communication with the anode chamber via a conduit, a cathode chamber having a cathode and a diffusion layer, wherein the diffusion layer is in fluid communication with an oxidizer, and a proton conducting, electrical non-conducting membrane electrolyte separating the chambers and positioned substantially adjacent to said diffusion layers. The membrane includes a catalyst exposed to each of the chambers for initiating chemical reactions to produce electricity. The system also includes a first valve for automatically controlling a flow of fuel from the fuel supply cartridge, where the first valve includes a shape memory alloy.

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1. A fuel concentration-actuated valve for controlling a fluid flow in a fuel cell comprising a first material which expands in direct relation to fuel concentration.2. The fuel concentration-actuated value according to claim 1, wherein the first material comprises a perfluorosulfonic acid polymer.3

1. A fuel concentration-actuated valve for controlling a fluid flow in a fuel cell comprising a first material which expands in direct relation to fuel concentration.2. The fuel concentration-actuated value according to claim 1, wherein the first material comprises a perfluorosulfonic acid polymer.3. A fuel cell comprising:a housing including an anode chamber, a cathode chamber, a protonically conductive, substantially electronically non-conductive membrane electrolyte separating said chambers; and a thermally sensitive actuator for controlling a flow of a fluid to/from the fuel cell. 4. The fuel cell according to claim 3, wherein said flow comprises a flow fuel or a flow of water.5. The fuel cell according to claim 3, wherein the anode chamber is in fluid communication with a fuel source and wherein said flow comprises a flow of fuel or a fuel mixture to the anode chamber.6. The fuel cell according to claim 5, wherein said fuel source communicates with said anode chamber via a conduit.7. The fuel cell according to claim 6, wherein said thermally-sensitive actuator is proximate said conduit.8. The fuel cell according to claim 6, wherein a temperature of said conduit reflects an operational temperature of said fuel cell.9. The fuel cell according to claim 3, wherein said thermally-sensitive actuator comprises a bi-metal material and/or a shape-memory alloy.10. The fuel cell according to claim 9, wherein said shape memory alloy comprises nickel and/or titanium.11. The fuel cell according to claim 6, wherein said conduit includes a deformable material.12. The fuel cell according to claim 5, wherein said fuel source is selected from the group consisting of: a fuel cartridge, a pump, and a mixing chamber.13. The fuel cell according to claim 11, wherein said actuator is positioned adjacent said deformable material.14. A fuel cell comprising:a housing including an anode chamber having a fuel mixture, said anode chamber in communication with a flow for adjusting the concentration of said fuel mixture, a cathode chamber, a protonically conductive, substantially electronically non-conductive membrane electrolyte separating said chambers; and a fuel concentration-actuated valve for controlling said fluid flow. 15. The fuel cell according to claim 14, wherein said flow comprises a fuel flow or a water flow.16. The fuel cell system according to claim 14, wherein said fuel mixture includes methanol.17. The fuel cell according to claim 14, wherein said fuel concentration-actuated valve comprises a first material which expands in direct relation to fuel concentration.18. The fuel cell according to claim 17, wherein said first material comprises a perfluorosulfonic acid polymer.19. A sensor for determining a concentration of fuel in a fuel mixture for a fuel cell comprising a conductor disposed on or within a first material, wherein said first material expands in proportion to the concentration of fuel based on exposure to a fluid.20. A sensor for determining the presence of a fuel in a fuel cell comprising a conductor disposed on or within a first material, wherein said first material expands in proportion to the concentration of fuel based on exposure to a fluid.21. The sensor according to claim 19 or 20, wherein said fluid is water, methanol or a methanol/water mixture.22. A direct methanol fuel cell system comprising:an anode chamber having an anode and a diffusion layer, wherein a fuel is introduced to the anode chamber via the diffusion layer; a fuel source in fluid communication with said anode chamber; a cathode chamber having a cathode and a diffusion layer, wherein said diffusion layer is in fluid communication with an oxidizer; and a protonically conductive, substantially, electronically non-conductive membrane electrolyte separating said chambers and positioned substantially adjacent to said diffusion layers; and a first valve for controlling a flow of a fluid in response to an operating parameter of the fuel cell system. 23. The system according to claim 22, where said valve comprises a thermally-sensitive actuator.24. The system according to claim 23, wherein said thermally-sensitive actuator comprises a shape memory material or alloy.25. The system according to claim 22, wherein said operating parameter comprises temperature and/or fuel concentration.26. The system according to claim 22, wherein said valve comprises a first material capable of expansion proportional to a change in fuel concentration.27. The system according to claim 26, wherein the first material comprises a perfluorosulfonic acid polymer.28. A switch for a fuel cell, said fuel cell comprising a housing including an anode chamber, a cathode chamber, a protonically conductive, substantially electronically non-conductive, membrane electrolyte separating said chambers, said switch comprising:a thermally-sensitive material wherein below a predetermined temperature, said switch is in a first position, and upon said fuel cell reaching said predetermined temperature said switch is switched to a second position. 29. The switch according to claim 28, wherein said thermally sensitive material comprises a shape memory alloy.30. The switch according to claim 29, wherein said thermally-actuated shape memory alloy comprises nickel and/or titanium.31. The switch according to claim 28, wherein said switch is disposed proximate to a portion of said fuel cell which reflects a current operational temperature of said fuel cell.32. The switch according to claim 28, wherein a positioning of said switch between said first position and said second position is variable depending upon an operating temperature of said fuel cell.33. A switch for a fuel cell, said fuel cell comprising a housing including an anode chamber, a cathode chamber, a protonically conductive, substantially electronically non-conductive, membrane electrolyte separating said chambers, said switch comprising:a first material having expansion properties upon exposure to a fluid, wherein said switch is in a first position prior to exposure to said fluid and said switch is in a second position after said first material is exposed to said fluid. 34. The switch according to claim 33, wherein a positioning of said switch between said first position and said second position is variable in a non-linear aspect in relation to an amount of said fluid said first material is exposed to.35. The switch according to claim 33, wherein said switch is placed in a third position upon exposure of said first material to a concentration of a second fluid.36. The switch according to claim 33, wherein the fluid comprises water or methanol.37. The switch according to claim 33, wherein an actual position of said third position is directly dependent upon said concentration of methanol.38. A thermally sensitive actuator for controlling a flow of a fluid to/from the fuel cell comprising a bi-metal material and/or a shape-memory alloy.39. The actuator according to claim 38, wherein said shape memory alloy comprises nickel and/or titanium.