Patent ID: 6995502

Claim:
A thermionic emission device, comprising: a substrate having a cavity extending into a surface of the substrate; a cathode having an electron-emitting coating disposed thereon, the cathode suspended near the cavity in the substrate; an anode constructed of an electrically conductive material, wherein the anode is configured to receive electrons emitted by the cathode; an elongated grid supported by at least one elongated wall-shaped support extending perpendicularly from the substrate, the wall-shaped support configured to be free standing and not supporting the anode, the elongated grid forming at least one aperture configured for allowing the passage of electrons therethrough and wherein the elongated grid is positioned between the cathode and the anode, but not directly in a path for electrons to travel from the cathode to the anode; a seal for creating a controlled environment in an area surrounding the anode, the cathode, and the elongated grid; and a circuit configured for heating the cathode.