Carbon Nanostructures in MEMS Applications

A new field emission pressure sensor based on carbon nanotubes (CNTs) emitting array is described in this paper. The pressure sensor is based on the principle that the field emission current is correlated with the electrical field intensity, i.e. the variable anode-emitter distance caused by pressure changes when the applied voltage is fixed. The sensor consists of two main parts, silicon etched membrane anode and CNTs emitting array cathode. The silicon single crystal (Si) wafer with <100> orientation is doped by phosphorus to obtain low resistant value. The CNTs were grown by plasma enhanced chemical vapour deposition by using iron as a catalyst in atmospheric pressure microwave torch. The field emission device has high emission current density, low threshold voltage, resistance to radiation, and quick response.