A.k.a. microfluidics. See Complex fluid dynamics. For fluid at even smaller scales (nanoscales), one talks about nanofluidics.

Microfluidics: Fluid physics at the nanoliter scale

Nanofluidics, from bulk to interfaces

Encyclopedia of Microfluidics and Nanofluidics

https://scholar.google.com/scholar?cites=17428969843030616661&as_sdt=2005&sciodt=0,5&hl=en

MAE6240 Fall 2012

Interfacial forces

See Phoretic mechanisms of colloids. Colloid Transport by Interfacial Forces

Osmotic effects

Diffusioosmosis, thermoosmosis, etc.