Abstract: A high-sensitivity field effect transistor using as a channel ultrafine fiber elements such as carbon nanotube, and a biosensor using it. The field effect transistor comprises a substrate, a source electrode and a drain electrode arranged on the substrate, a channel for electrically connecting the source electrode with the drain electrode, and a gate electrode causing polarization due to the movement of free electrons in the substrate. For example, the substrate has a support substrate consisting of semiconductor or metal, a first insulating film formed on a first surface of the support substrate, and a second insulating film formed on a second surface of the support substrate, the source electrode, the drain electrode, and the channel arranged on the first insulating film, the gate electrode disposed on the second insulating film.

Abstract: A single-electron transistor comprising at least a substrate, a source electrode and a drain electrode formed on top of the substrate opposing to each other, and a channel arranged between the source electrode is disclosed wherein the channel is composed of ultra fine fibers. By having such a constitution, a sensor can have excellent sensitivity.

Abstract: A single-electron transistor comprising at least a substrate, a source electrode and a drain electrode formed on top of the substrate opposing to each other, and a channel arranged between the source electrode is disclosed wherein the channel is composed of ultra fine fibers. By having such a constitution, a sensor can have excellent sensitivity.

Abstract: A single-electron transistor comprising at least a substrate, a source electrode and a drain electrode formed on top of the substrate opposing to each other, and a channel arranged between the source electrode is disclosed wherein the channel is composed of ultra fine fibers. By having such a constitution, a sensor can have excellent sensitivity.

Abstract: This invention provides a process for producing a carbon nanotube electric field effect transistor that can improve yield in channel preparation. Carbon nanotubes dispersed in a mixed acid composed of sulfuric acid and nitric acid are subjected to radical treatment with aqueous hydrogen peroxide to cut the carbon nanotubes and thus to provide carboxyl-introduced carbon nanotube fragments. The carbon nanotube fragments are attached, through a covalent bond and/or an electrostatic bond, to a site, where a source electrode is to be formed, and a site where a drain electrode is to be formed, in a substrate with a functional group, to be attached to a carboxyl group, introduced thereinto. The carbon nanotube fragments attached to the substrate are attached to carbon nanotubes as channels through n-n interaction to fix the carbon nanotubes as channels to the substrate.

Abstract: A high-sensitivity field effect transistor using as a channel ultrafine fiber elements such as carbon nanotube, and a biosensor using it. The field effect transistor comprises a substrate, a source electrode and a drain electrode arranged on the substrate, a channel for electrically connecting the source electrode with the drain electrode, and a gate electrode causing polarization due to the movement of free electrons in the substrate. For example, the substrate has a support substrate consisting of semiconductor or metal, a first insulating film formed on a first surface of the support substrate, and a second insulating film formed on a second surface of the support substrate, the source electrode, the drain electrode, and the channel arranged on the first insulating film, the gate electrode disposed on the second insulating film.

Abstract: A single-electron transistor comprising at least a substrate, a source electrode and a drain electrode formed on top of the substrate opposing to each other, and a channel arranged between the source electrode is disclosed wherein the channel is composed of ultra fine fibers. By having such a constitution, a sensor can have excellent sensitivity.

Abstract: A probe for measuring a leakage magnetic field includes a substrate, a flexible cantilever having one end fixed to the substrate and a free end, and at least one magneto resistive element arranged on the free end of the cantilever. The magneto resistive element has a width within a range from 10 nm to 1 &mgr;m as measured in a direction perpendicular to a longitudinal direction of the cantilever and in a direction in which the cantilever can be deflected.

Abstract: At the forefront of a probe is formed a carbon nanotube having an armchair type crystal structure or of which the forefront is chemically modified with modifying molecules.

Abstract: At the forefront of a probe is formed a carbon nanotube having an armchair type crystal structure or of which the forefront is chemically modified with modifying molecules.

Abstract: A probe for measuring a leakage magnetic field includes a substrate, a flexible cantilever having one end fixed to the substrate and a free end, and at least one magneto resistive element arranged on the free end of the cantilever. The magneto resistive element has a width within a range from 10 nm to 1 &mgr;m as measured in a direction vertical to a longitudinal direction of the cantilever and also to a direction in which the cantilever can be deflected.