Patent ID: 6852996

Claim:
A sensor, comprising: an organic semiconductor layer having a sensing surface on one side and a contact surface on the side of the layer opposite from the sensing surface, the layer comprising material having majority mobile charge carriers of a first conductivity type distributed throughout a region beneath the sensing surface; a first conductive plate spaced from the sensing surface; a second conductive plate spaced from the sensing surface and from the first conductive plate; and a gate electrode interposed between the first and second conductive plates, the organic semiconductor layer being so constructed that a depletion region will be formed therein beneath the sensing surface in response to a voltage bias applied to the gate electrode, a dimension of the depletion region varying in response to the presence of an object proximate to the sensing surface, the variation in the dimension being detectable by sensing a signal communicated from the first conductive plate to the second conductive plate through the organic semiconductor layer below the sensing surface; wherein the first conductive plate, the second conductive plate, and the gate electrode are each disposed in contact with the contact surface.