US Patent 7628959 - Nanowire hydrogen gas sensor

http://www.freepatentsonline.com/7628959.html

This patent from the University of California has some early priority (2001) and includes some basic claims to using metallic nanowire arrays as a hydrogen sensor. Claim 1 reads:

1. A hydrogen gas sensor comprising:

a first circuit exhibiting an increase in conductivity when exposed to hydrogen gas,

wherein the first circuit comprises an array of nanowires,

wherein a plurality of nanowires in the array are electrically discontinuous in the absence of hydrogen gas,

first and second electrical contacts coupled to the first circuit,

a power source coupled to the first and second electrical contacts, and

a second circuit coupled to the first circuit for sensing current across the first circuit.