Challenges in Nanofluidics—Beyond Navier–Stokes at the Molecular Scale

The fluid dynamics of macroscopic and microscopic systems is well developed and has been extensively validated. Its extraordinary success makes it tempting to apply Navier–Stokes fluid dynamics without modification to systems of ever decreasing dimensions as studies of nanofluidics become more prevalent. However, this can result in serious error. In this paper, we discuss several ways in which nanoconfined fluid flow differs from macroscopic flow. We give particular attention to several topics that have recently received attention in the literature: slip, spin angular momentum coupling, nonlocal stress response and density inhomogeneity. In principle, all of these effects can now be accurately modelled using validated theories. Although the basic principles are now fairly well understood, much work remains to be done in their application.

Impact of the thermal motion of silicon atoms on the viscosity of nanoconfined aqueous NaCl solution

The properties of nanoconfined fluid are critical for the design and precise control of nanofluidic devices. To understand the fundamental details of the viscosity of nanoconfined aqueous NaCl solution, we investigated the impact of the thermal motion of silicon atoms on the viscosity of nanoconfined aqueous NaCl solution using molecular dynamic simulations. The results show that thermal motion of silicon atoms can decrease the viscosity of NaCl solution, and this impact is significant when the shear rate is small.