Nano watermill driven by the revolving charge

摘要

Using molecular dynamics simulations, we propose a novel nanoscale watermillfor unidirectional transport of water molecules through a curved single-walledcarbon nanotube (SWNT). In this nanoscale system, a revolving charge isintroduced to drive water chain confined inside the SWNT, which is served asnano waterwheel and nano engine. A resonance-like phenomenon is found that therevolving frequency of the charge plays a key role in pumping water chain. Thewater flux across the SWNT increases with respect to the revolving frequency ofthe external charge and reaches the maximum when the frequency is 4 THz.Correspondingly, the number of the hydrogen bonds of water chain inside theSWNT decreases dramatically with the frequency ranging from 4 THz to 25 THz.The mechanism behind the resonant phenomenon has been investigatedsystematically. Our findings are helpful for designing nanoscale fluidicdevices and energy converters.