US Patent 7564246 - CNT field emission pressure sensor

http://www.freepatentsonline.com/7564246.html

Carbon nanotube (CNT) field emitters are most often mentioned for applications in displays but another potential application is in pressure gages. This patent teaches an improved version of a CNT pressure gage with less potential damage to the nanotube emitters by using a multiple grid system. Claim 1 reads:

1. A pressure sensor using a field emission of a carbon nano-tube, comprising:

an array of carbon nano-tubes formed on a metallic layer;

a first grid disposed on the array of the carbon nano-tubes;

a second grid disposed on the first grid such that the second grid is spaced apart by a first distance from the first grid; and

a collector disposed on the second grid such that the collector is spaced apart by a second distance from the second grid,

whereby electrons emitted from the carbon nano-tube are collided with gas molecules to be ionized forming an ionized cation, and the ionized cation is sensed by the collector to be outputted as an electrical signal.