US Patent 7874250 - High power nanoswitch for wellbore

http://www.freepatentsonline.com/7874250.html

This patent from Schlumberger Technology teaches switches used in the high temperature environment of wellbore applications using nanotube field emitters to enable high voltage (>1400 V DC) switching. Claim 1 reads:

1. An apparatus comprising:

a component for use in a wellbore;

a nano-diode coupled to the component to enable activation of the component,

wherein the nano-diode comprises an electrode and nano-emitters formed on the electrode, the nano-emitters to emit electrons.