Nanoscale fluid pumping using a symmetric temperature gradient: a molecular dynamics study

ABSTRACT In this study, using the molecular dynamics simulation method, three systems for fluid pumping at the nanoscale have been proposed based on the thermo-osmotic mechanism. These pumps work by applying a symmetric temperature gradient along the wall of a nanopore, which is asymmetric in shape or material. The three systems are a composite nanotube, a conical nanotube, and a composite conical nanopore. The simulation results show that, in all of the proposed systems, the fluid can be pumped continuously by means of heat energy and without using any external force or moving component. The physical mechanisms of the flow in these pumps are clarified using the principles of the thermo-osmotic phenomenon. The simulations show the geometry of the pump and the fluid-solid interaction strength play an important role in determining the pumping strength in all systems. It is shown that a composite conical nanopump compared to other proposed systems has a better performance in fluid pumping.