Thermally-driven nanoscale pump by molecular dynamics simulation

The feasibility of a device is studied that drives a fluid in nanoscale channel using a phenomenon called thermal transpiration, where the fluid is set in motion by a temperature gradient in the fluid-solid interface. Four different types of systems are considered using the Molecular Dynamics Simulation. They differ mainly in channel configuration and the way the gradient is applied. The simulation results show that the design of the device has major technical obstacles. One is a difficulty in imposing a sufficiently-large temperature gradient in the small scale. In this case, the feature like thermal-contact-resistance at the interface needs to be included in design considerations. The second is a limited flow-development under an increased viscous drag in the narrow channel. One of the considered systems proves to be effective in a pumping operation. The system is based on a unit that repeats itself periodically in the system. The unit is composed of two regions: one that drives a fluid by thermophoretic force and the other that guides the fluid smoothly with little thermophoretic force. The latter region is made of a thermally-insulating, weakly-interacting