In accordance with the present invention, nanometer-scale reversible electronic switches are provided that can be assembled to make cross-bar circuits that provide memory, logic, and communications functions. The electronic switches, or crossed-wire devices, comprise a pair of crossed wires that form a junction where one wire crosses another at an angle other than zero degrees and at least one connector species connecting the pair of crossed wires in the junction. The junction has a functional dimension in nanometers, wherein at least one connector species and the pair of crossed wires forms an electrochemical cell. The connector species comprises a bistable molecule having a general formula given by ##STR1## The bistable molecules evidence high switching speed. Such molecules are essentially stable against switching due to thermal fluctuations.
CROSS-REFERENCE TO RELATED APPLICATIONS
The present application is also related to the following applications and patents: Ser. No. 09/280,048 ("Chemically Synthesized and Assembled Electronic Devices"); Ser. No. 09/280,225 ("Molecular Wire Crossbar Interconnects for Signal Routing and Communications"); Ser. No. 09/282,045 ("Molecular Wire Crossbar Logic"); Ser. No 09/282,049 ("Demultiplexer for a Molecular Wire Crossbar Network"); and Ser. No. 09/280,188 ("Molecular Wire Transistors"), all filed on Mar. 29, 1999, and U.S. Pat. No. 6,128,214, issued on Oct. 3, 2000 ("Molecular Wire Crossbar Memory").
The present application is an improvement over the foregoing applications and patent in that it utilizes a new type of switching mechanism, namely, an electric field-induced rotation of a molecular group or rotor that carries a large dipole moment.
Diodes and switches are combined in a single molecular species. Thus, the single molecular species is capable of performing more than one function. A single molecular species having both diode and switch functionalities is provided. The molecular species is represented by the formula: ##STR1## where A and B are non-identical conducting moieties, I is an insulating bridge between A and B, CL and CR are connectors to left and right electrodes, respectively, and "+" and "-" represent a rotatable dipolar moiety. Further, a diode-switch combination is provided, comprising the single molecular species. The teachings herein provide a set of principles to combine diodes and switches within one molecular species. Further, with the present teachings, only a single molecular species is needed for the fabrication of viable moletronic devices such as crossbar memory arrays. Consequently, device fabrication is easier and cheaper, and the device itself less faulty and more reliable.
A nanowire comprising only metal having an average length of 1 .mu.m or more which could not be produced in the prior art, and a method of manufacturing this wire. This invention provides a method of manufacturing a metal nanowire, which comprises the step of reducing a nanofiber comprising a metal complex peptide lipid formed from the two-headed peptide lipid represented by the general formula (I): ##STR1## in which Val is a valine residue, m is 1-3 and n is 6-18, and a metal ion, using 5-10 equivalents of a reducing agent relative to the two-headed peptide lipid. It further provides a metal nanowire having an average diameter of 10-20 nm and average length of 1 .mu.m or more. It is preferred that the metal is copper.
An architecture for computing includes nanometer scale crossbar switches configured to perform a logical function in response to a sequence of pulses that encode logic values in the nanometer scale crossbar switches as impedances.
A bistable molecular switch can have a highly conjugated first state and a less conjugated second state. The bistable molecular switch can be configured such that application of an electric field reversibly switches the molecular switch from the first state to the second state. Additionally, the bistable molecular switch can include a hydrophobic moiety and a hydrophilic moiety. Such molecular switches can be incorporated into a thin film as part of a molecular switch system which can include a layer of molecular switches between a first electrode layer and a second electrode layer. The layer of molecular switches can have substantially all of the molecular switches having their hydrophilic moiety oriented in the same direction. An electric potential can then be induced between the first and second electrode layers sufficient to switch the molecular switches from the first or second state to the second or first state, respectively. The first and second states have differences in resistivity which are suitable for use in electronic applications. Thin films containing these oriented molecular switches can be used to produce a wide variety of electronic components such as ROM memory and the like.
Bistable molecules are provided with at least one photosensitive functional group. As thus constituted, the bistable molecules are photopatternable, thereby allowing fabrication of micrometer-scale and nanometer-scale circuits in discrete areas without relying on a top conductor as a mask. The bistable molecules may comprise molecules that undergo redox reactions, such as rotaxanes and catenanes, or may comprise molecules that undergo an electric-field-induced band gap change that causes the molecules, or a portion thereof, to rotate, bend, twist, or otherwise change from a substantially fully conjugated state to a less conjugated state. The change in states in the latter case results in a change in electrical conductivity.
