NanomachinesNanomachines

The Thermodynamic RatchetThe Thermodynamic Ratchet

By Owen HickeyBy Owen Hickey

Why are nanomachines differentWhy are nanomachines different

When we talk about nano-distances, When we talk about nano-distances, nano-masses, and nano-fuel we get nano-masses, and nano-fuel we get nano-forcesnano-forces

Nanomachines must therefore take Nanomachines must therefore take into account thermal fluctuations into account thermal fluctuations (Brownian noise) when:(Brownian noise) when:

F~kF~kBBTT

Feynmann’s RatchetFeynmann’s Ratchet

Thermal Noise on SpringThermal Noise on Spring

Working Feynmann RatchetWorking Feynmann Ratchet

Works if spring is at lower temperature then thePawl (T2<T1)

Ratchets: simple nanomachinesRatchets: simple nanomachines

Hammond et al.

Actual DeviceActual DeviceMicromachine

Parrondo’s Paradox and the Parrondo’s Paradox and the RatchetRatchet

Applicability in the Macroworld:Applicability in the Macroworld:example by R.D. Astumianexample by R.D. Astumian

Another implementation on the Another implementation on the nanoscalenanoscale

Refraction ThroughBead Causes Motion

Biological Applications (Yanagida)Biological Applications (Yanagida)

Jumps are discrete 5.5-27.5 nm, all Jumps are discrete 5.5-27.5 nm, all multiples of 5.5 nm, uses one ATPmultiples of 5.5 nm, uses one ATP

Rocking RatchetRocking Ratchet

Rocking with AC field cause motion Rocking with AC field cause motion to the leftto the left

Hot-Cold Ratchet by HanggiHot-Cold Ratchet by Hanggi

Possible? (such a quick T change)Possible? (such a quick T change)

Hanggi’s Quantum RatchetHanggi’s Quantum Ratchet

ee- - waveguidewaveguide

Applied weak AC fieldApplied weak AC field

Low T,Left:tunnelingLow T,Left:tunneling

High T,Right:thermalHigh T,Right:thermal

Heat PumpHeat Pump

Actual Quantum SystemActual Quantum System

Positive CurrentIs to the left

The EndThe End