July 29/30 DARPA-meeting 1
Technological BasisTechnological BasisTechnological BasisTechnological Basis
Fundamental PhysicsFundamental PhysicsFundamental PhysicsFundamental Physics
Device ApplicationsDevice ApplicationsDevice ApplicationsDevice Applications
Ion Channels, Carbon Nanotubes, wet/dryIon Channels, Carbon Nanotubes, wet/dry
July 29/30 DARPA-meeting 2
Technological BasisTechnological Basis
Fundamental PhysicsFundamental Physics
Device ApplicationsDevice Applications
Technological BasisTechnological Basis
wet/dry/interfacewet/dry/interface
Bio-ChannelsBio-Channels NanotubesNanotubes
The technological basis is provided by nature
The increased knowledge in the chemistry and physics of Ion Channels (location of fixed charges etc.) permits progress in simulation and to learn from nature
July 29/30 DARPA-meeting 3
Technological BasisTechnological Basis
Fundamental PhysicsFundamental Physics
Device ApplicationsDevice Applications
Technological BasisTechnological Basis
NanotubesNanotubes
Synthetic techniques are in infancy
• Laser-ablation (expensive)• Arc-evaporation (MWNT)• CVD in chamberwill give soot to be purified• CVD on chipwill give NTs in desired locations
- Need for control of structure of a single tube
Bio-ChannelsBio-Channels
The technological basis is provided by nature
The increased knowledge in the chemistry and physics of Ion Channels (location of fixed charges etc.) permits progress in simulation and to learn from natureNanotubes grow from CoSi islands
July 29/30 DARPA-meeting 4
Technological BasisTechnological Basis
Fundamental PhysicsFundamental Physics
Device ApplicationsDevice Applications
Technological BasisTechnological Basis
As a self-organized structure, tubes have various symmetry and controllable electronic properties
Bio-ChannelsBio-Channels
The technological basis is provided by nature
The increased knowledge in the chemistry and physics of Ion Channels (location of fixed charges etc.) permits progress in simulation and to learn from nature
NanotubesNanotubes
Synthetic techniques are in infancy
July 29/30 DARPA-meeting 5
Technological BasisTechnological Basis
Fundamental PhysicsFundamental Physics
Device ApplicationsDevice Applications
Technological BasisTechnological Basis
Characterization e.g. by Tunneling Spectroscopy
Bio-ChannelsBio-Channels
The technological basis is provided by nature
The increased knowledge in the chemistry and physics of Ion Channels (location of fixed charges etc.) permits progress in simulation and to learn from nature
As a self-organized structure, tubes have various symmetry and controllable electronic properties
NanotubesNanotubes
Synthetic techniques are in infancy
July 29/30 DARPA-meeting 6
Technological BasisTechnological BasisTechnological BasisTechnological Basis
Fundamental PhysicsFundamental PhysicsFundamental PhysicsFundamental Physics
July 29/30 DARPA-meeting 7
Technological BasisTechnological Basis
Fundamental PhysicsFundamental Physics
Device ApplicationsDevice Applications
Fundamental PhysicsFundamental Physics
Bio-ChannelsBio-Channels NanotubesNanotubes
Classical vs. Quantum Mechanical Description
• Casimir Forces at nanoscalequantum electrodynamical description - full microscopics vs. continuum theory
pp11
pp22
EE
J.D.van der Waals, 1873. J.D.van der Waals, 1873. F. London, 1930F. London, 1930H.B.G. Casimir, 1949H.B.G. Casimir, 1949
July 29/30 DARPA-meeting 8
Technological BasisTechnological Basis
Fundamental PhysicsFundamental Physics
Device ApplicationsDevice Applications
Fundamental PhysicsFundamental Physics
NanotubesNanotubes
pp11
pp22
EE
Bio-ChannelsBio-Channels
Classical vs. Quantum Mechanical Description
• Casimir Forces at nanoscalequantum electrodynamical description - full microscopics vs. continuum theory
J.D.van der Waals, 1873. J.D.van der Waals, 1873. F. London, 1930F. London, 1930H.B.G. Casimir, 1949H.B.G. Casimir, 1949
July 29/30 DARPA-meeting 9
Technological BasisTechnological Basis
Fundamental PhysicsFundamental Physics
Device ApplicationsDevice Applications
Fundamental PhysicsFundamental Physics
Bio-ChannelsBio-Channels NanotubesNanotubesClassical vs. Quantum Mechanical Description
Multiple scales in modeling• Equations of Continuity
July 29/30 DARPA-meeting 10
Technological BasisTechnological Basis
Fundamental PhysicsFundamental Physics
Device ApplicationsDevice Applications
Fundamental PhysicsFundamental Physics
Bio-ChannelsBio-Channels NanotubesNanotubesClassical vs. Quantum Mechanical Description
Multiple scales in modeling• Equations of Continuity• Monte-Carlo solution of the Boltzmann transport equation• Finite size of the ions !!• Quantum Effects : van der Waals, Casimir, DFT
July 29/30 DARPA-meeting 11
Technological BasisTechnological Basis
Fundamental PhysicsFundamental Physics
Device ApplicationsDevice Applications
Fundamental PhysicsFundamental Physics
NanotubesNanotubes
Classical vs. Quantum Mechanical Description
-3 -2 -1 1 2 3
-3
-2
-1
1
2
3
-6 -4 -2 2 4 6
-3
-2
-1
1
2
3
Bio-ChannelsBio-ChannelsClassical vs. Quantum Mechanical Description
Multiple scales in modeling• Equations of Continuity• Monte-Carlo solution of the Boltzmann transport equation• Finite size of the ions !!• Quantum Effects : van der Waals, Casimir, DFT
July 29/30 DARPA-meeting 12
Technological BasisTechnological Basis
Fundamental PhysicsFundamental Physics
Device ApplicationsDevice Applications
Fundamental PhysicsFundamental Physics
NanotubesNanotubes
Multiple scales in modeling
Classical vs. Quantum Mechanical Description
• Continuum theory of elastic deformationswith Molecular Dynamics for parametrization• Classical electrostaticswith atomistic quantum capaciatnce• van der Waals
Nanotube Electromechanical Switch
0 10 20 30 40z,nm
0
0.2
0.4
0.6
0.8
, e/
nm
Charge Density Profile
July 29/30 DARPA-meeting 13
Technological BasisTechnological BasisTechnological BasisTechnological Basis
Fundamental PhysicsFundamental PhysicsFundamental PhysicsFundamental Physics
Device ApplicationsDevice ApplicationsDevice ApplicationsDevice Applications
July 29/30 DARPA-meeting 14
Technological BasisTechnological Basis
Fundamental PhysicsFundamental Physics
Device ApplicationsDevice Applications
Device ApplicationsDevice Applications
Bio-ChannelsBio-Channels Nanotube FETsNanotube FETs
High ION/IOFF ratio (approaching infinity)
Operation voltage: low
Device characteristics: slow
July 29/30 DARPA-meeting 15
Technological BasisTechnological Basis
Fundamental PhysicsFundamental Physics
Device ApplicationsDevice Applications
Device ApplicationsDevice Applications
Nanotube FETsNanotube FETs
Significant improvement (105) of ION/IOFF ratio was claimed in 4 years
Best NT-FETs operate as unconventional SB-FET
S.J. Tans, 1998. S.J. Tans, 1998. Ph. Avouris, 1998.Ph. Avouris, 1998.
C. Dekker, 2001. C. Dekker, 2001. Ph. Avouris, 2002.Ph. Avouris, 2002.
Bio-ChannelsBio-Channels
High ION/IOFF ratio (approaching infinity)
Operation voltage : low
Device characteristics : slow
July 29/30 DARPA-meeting 16
Technological BasisTechnological Basis
Fundamental PhysicsFundamental Physics
Device ApplicationsDevice Applications
Device ApplicationsDevice Applications
Nanotube FETsNanotube FETs
Significant improvement (105) of ION/IOFF ratio was claimed in 4 years
Best NT-FETs operate as unconventional SB-FET
S.J. Tans, 1998. S.J. Tans, 1998. Ph. Avouris, 1998.Ph. Avouris, 1998.
C. Dekker, 2001. C. Dekker, 2001. Ph. Avouris, 2002.Ph. Avouris, 2002.
July 29/30 DARPA-meeting 17
Technological BasisTechnological Basis
Fundamental PhysicsFundamental Physics
Device ApplicationsDevice Applications
Device ApplicationsDevice Applications
Nanotube FETsNanotube FETs
Significant improvement (105) of ION/IOFF ratio was done in 4 years
Best NT-FETs operate as unconventional SB-FET
Sub-threshold slope ??
S.J. Tans, 1998. S.J. Tans, 1998. Ph. Avouris, 1998.Ph. Avouris, 1998.
C. Dekker, 2001. C. Dekker, 2001. Ph. Avouris, 2002.Ph. Avouris, 2002.
High sensitivity to oxygen
Nanotube artificial ion-atom- molecule channels
July 29/30 DARPA-meeting 18
Technological BasisTechnological Basis
Fundamental PhysicsFundamental Physics
Device ApplicationsDevice Applications
ConclusionsConclusions
Powerful multi scale simulation approaches to both Biological Ion Channels and Carbon Nanotubes possible in near future
Both areas can learn from each other; the wet-dry interface being of particular interest
Interesting device opportunities: low power off/on -> 0
molecular transport in dry world