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Moletronics

http://www.quinion.com/words/turnsofphrase/tp-mol1.htm

Late 1940s -Mulliken& Szent-Gyorgi’stheory of molecularconduction.

1959 - Feynman 1974 - Ratner &

Aviram proposedmolecular rectifiers.

1999 - first singlemoleculemeasurementsdemonstrated.

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Single crystalnanowires (Si, Ge, etc.)

Carbon nanotubes Quantum dots Organic molecules Biomolecules

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Scientific American

Break junctions. Electric cut junctions. SAM on curved

electrodes. SPM, STM.

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Single electron devices. Single atom switching. Switching by biomolecular

recognition. Spintronics.

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Crossbar architectures

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Molecular devices

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Some difficulties in data interpretation

Contact resistance. Multiple conduction mechanisms. Molecular distortions. Specific example: DNA conductivity

Insulator, semiconductor, conductor, superconductor.

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Key difficulties to be overcome formolecular circuit design

Scalability to near molecular dimensions. Tolerance of manufacturing defects. Introduction of non-traditional fabrication methods

(e.g. chemically directed self-assembly). Bridging between device densities potentially

achievable at molecular scale with those at forstandard lithography.

Simplicity of fabrication.

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Crossbars and demultiplexers

Memory circuitdetails shown.

2n memory bits(black nanowirecrossings) canbe addressedby n pairs ofmicro wires(blue).

MEcomponentslocated atnanowirescrossings.

Binary tree multiplexer

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Summary of ME advances in recent years:

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Each junction containedseveral millionmolecules.

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Bio•Nano•Technology

Biomolecules in artificial nanosystems. Biological inspiration or principles. Engineering and in vitro evolution of

biomolecules. Chemical self-assembly. Molecular electronics.