US Patent 7842432 - Nanowire diffusion control barrier for fuel cells

http://www.freepatentsonline.com/7842432.html

This patent from Nanosys teaches a fuel cell membrane formed from a mixture of semiconductor nanowires and graphene. Claim 2 reads:

2. A fuel cell comprising

a fuel source,

a proton exchange membrane,

an anode electrode,

a cathode electrode and

a diffusion-controlling barrier comprising an interconnected network of nanowires, wherein fuel concentration at the proton exchange membrane is less than about 30% of that of the fuel source.