A US research team has developed the first flexible hydrogen sensors from single-walled carbon nanotubes (SWNT) coated with individual palladium nanoparticles, it has been reported.

Argonne National Laboratory's sensors improve upon existing technology in that they are more efficient at detecting chemicals and are able to recover more quickly.

Moreover, through using SWNT and palladium composites instead of films of pure palladium, the fabrication costs are reduced.

Meanwhile, the employment of plastic sheets as the substrate, which forms the basis of the device, serves to increase its mechanical strength and reduce its overall weight.

In particular, the device's sensitivity to hydrogen - it will reveal a change of 75 per cent in resistance even if the hydrogen in air constitutes just 0.05 per cent - is set to make it especially useful for detecting leaks in hydrogen fuel cell-powered cars as well as in aviation craft fuelled by hydrogen.

Yugang Sun, who undertook the research with Hau Wang, told nanotechweb: "For example, individual rigid sensors could not easily detect hydrogen leaking out of tiny pinholes in the pipe of a space shuttle because we do not know where the holes are located in the first place.

"In contrast, the leakage could be detected by a dense of array of flexible sensors laminated onto the entire surface of the pipe."

It is hoped that the technology can now be scaled up to be used in large-area sensor rays.

Source:

Bendy hydrogen sensors take shape, 19/06/07
http://nanotechweb.org/articles/news/6/6/16?alert=1

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