Molecular-level machines energy problem

The problem of the construction of artificial molecular-level machines was posed for the first time by Richard P. Feynman, Nobel Laureate in Physics, in his famous address There Is Plenty of Room at the Bottom to the American Physical Society in 1959 [12] "... What are the possibilities of small but movable machines . ..An internal combustion engine of molecular size is impossible. Other chemical reactions, liberating energy when cold, can be used instead.. ..Lubrication might not be necessary bearings could run dry they would not run hot because heat escapes from such a small device very rapidly... 

For macroscopic machines, the energy payment for information can be relatively small as compared with the useful work performed by the machine. However, this is not the case, in general, for machines operating at the level of individual molecules. We will now consider two aspects of the problem of optimal efBciency of molecular machine action ... 

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