1. A fuel cell comprising:
at least two bipolar plates;
a membrane electrode assembly, which is arranged between the bipolar plates and has at least one contact place with each bipolar plate, making indirect or direct electrical contact; and
a short-circuiting means provided in an area between or in the two bipolar plates, for short-circuiting the bipolar plates in response to the introduction of heat.
2. The fuel cell as claimed in claim 1, wherein:
the bipolar plates and the membrane electrode assembly have at least one common contact place; and
the short-circuiting means is provided in the area of the contact place for each respective bipolar plate.
3. The fuel cell as claimed in claim 1, wherein the short-circuiting means is arranged between at least one bipolar plate and the membrane electrode assembly.
4. The fuel cell as claimed in claim 1, wherein the short-circuiting means is one of:
integrated in the respective bipolar plates;
integrated in the membrane electrode assembly;
fitted to the bipolar plates; and
fitted to the membrane electrode assembly.
5. The fuel cell as claimed in claim 1, wherein the short-circuiting means is fusible and has a melting point between 50\xb0 C. and 120\xb0 C.
6. The fuel cell as claimed in claim 1, wherein the short-circuiting means is fusible and has a melting point between 80\xb0 C. and 90\xb0 C.
7. The fuel cell as claimed in claim 1, wherein at least one of the following is true:
each bipolar plate has a channel or pore structure to ensure that the melted short-circuiting means flows; and
the membrane electrode assembly has a channel or pore structure to ensure that the melted short-circuiting means flows.
8. The fuel cell as claimed in claim 1, wherein the short-circuiting means:
makes contact with both bipolar plates irrespective of the temperature;
is electrically conductive in a temperature range between 50\xb0 C. and 120\xb0 C.; and
is electrically isolating in other temperature ranges.
9. The fuel cell as claimed in claim 1, wherein the short-circuiting means:
makes contact with both bipolar plates irrespective of the temperature;
is electrically conductive in a temperature range between 80\xb0 C. and 90\xb0 C.; and
is electrically isolating in other temperature ranges.
10. The fuel cell as claimed in claim 1, wherein the membrane electrode assemble includes a polymer electrolyte membrane that can be melted through by means of the short-circuiting means.
11. The fuel cell as claimed in claim 1, wherein:
at least two fuel cells form a fuel cell stack, which is connected to a common gas inlet channel; and
the fuel cells or fuel cell parts which are arranged in an area of the gas inlet channel include the short-circuiting means.
12. The fuel cell as claimed in claim 11, wherein the fuel cells or fuel cell parts which are arranged in an area of the fuel cell stack where the temperature is critical have the short-circuiting means.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A thin layer chromatography plate, comprising:
a substrate; and
a plurality of stationary phase structures extending generally away from the substrate, wherein at least some of the plurality of stationary phase structures exhibit an elongated geometry which is substantially free of carbon nanotubes, and wherein the plurality of stationary phase structures exhibit a non-linear configuration.
2. The thin layer chromatography plate as recited in claim 1, wherein the at least some of the plurality of stationary phase structures exhibit an average aspect ratio between about 10,000 and about 2,000,000.
3. The thin layer chromatography plate as recited in claim 1, wherein the plurality of stationary phase structures exhibit an average spacing of about 4 \u03bcm and about 8 \u03bcm.
4. The thin layer chromatography plate as recited in claim 1, wherein the plurality of stationary phase structures are functionalized.
5. The thin layer chromatography plate as recited in claim 1, wherein the plurality of stationary phase structures are attached over the substrate without a binder.
6. The thin layer chromatography plate as recited in claim 1, wherein the wherein at least some of the plurality of stationary phase structures are at least partially intertwined with each other.
7. The thin layer chromatography plate as recited in claim 1, further comprising a catalyst layer including a first portion on which a first portion of the plurality of stationary phase structures are disposed and at least a second portion on which a second portion of the plurality of stationary phase structures are disposed, wherein the first and at least a second portions of the catalyst layer are spaced from each other and exhibit a selected non-linear configuration.
8. The thin layer chromatography plate as recited in claim 1, wherein a density of the plurality of stationary phase structures is selectively varied in different regions of the plurality of stationary phase structures.
9. The thin layer chromatography plate as recited in claim 1, wherein at least a portion of the plurality of stationary phase structures are hollow.
10. The thin layer chromatography plate as recited in claim 1, wherein at least a portion of the plurality of stationary phase structures form nanowires.
11. A thin layer chromatography plate, comprising:
a substrate; and
a plurality of stationary phase structures extending generally away from the substrate, wherein a first portion and at least a second portion of the plurality of stationary phase structures are arranged in a non-linear configuration.
12. The thin layer chromatography plate as recited in claim 11, wherein the at least a portion of the plurality of stationary phase structures exhibit an average aspect ratio between about 10,000 and about 2,000,000.
13. The thin layer chromatography plate as recited in claim 11, wherein the plurality of stationary phase structures are functionalized.
14. The thin layer chromatography plate as recited in claim 11, wherein the plurality of stationary phase structures are attached over the substrate without a binder.
15. The thin layer chromatography plate as recited in claim 11, wherein the stationary phase structures of the first portion are at least partially intertwined with each other and the stationary phase structures of the at least a second portion are at least partially intertwined with each other.
16. The thin layer chromatography plate as recited in claim 11, further comprising a catalyst layer including a first portion on which the first portion of the plurality of stationary phase structures are disposed and at least a second portion on which the at least a second portion of the plurality of stationary phase structures are disposed, wherein the first and at least a second portions of the catalyst layer are spaced from each other and exhibit a selected non-linear configuration.
17. The thin layer chromatography plate as recited in claim 11, wherein a density of the plurality of stationary phase structures is selectively varied in different regions of the plurality of stationary phase structures.
18. The thin layer chromatography plate as recited in claim 11, wherein a composition of plurality of stationary phase structures is selectively varied in different regions of the plurality of stationary phase structures.
19. The thin layer chromatography plate as recited in claim 11, further comprising:
a first region wherein the plurality of stationary phase structures therein are selectively functionalized with a first chemical species; and
at least a second region wherein the plurality of stationary phase structures therein are selectively functionalized with a second chemical species that allows for greater retention of at least one analyte than the first chemical species in the first region.
20. A thin layer chromatography plate, comprising:
a substrate;
a catalyst layer disposed on the substrate, the catalyst layer including a first portion and at least a second portion spaced from each other in a non-linear configuration;
a plurality of stationary phase structures extending generally away from the substrate, wherein at least some of the plurality of stationary phase structures exhibit an elongated geometry which is substantially free of carbon nanotubes, a first portion and at least a second portion of the plurality of stationary phase structures each disposed on a respective one of the first and at least a second portion of the catalyst layer; and
wherein one or more of a density or a composition of a first group of the plurality of stationary phase structures is different than a density or a composition of a second group of the plurality of stationary phase structures.