Eur. Phys. J. E (2019) 42: 1
https://doi.org/10.1140/epje/i2019-11759-1

Topical Review

Capillarity-driven migration of small objects: A critical review

Department of Engineering Mechanics, College of Pipeline and Civil Engineering, China University of Petroleum (East China), 266580, Qingdao, China

^* e-mail: liujianlin@upc.edu.cn

Received: 28 October 2018
Accepted: 30 November 2018
Published online: 8 January 2019

Abstract

The phenomena on the capillarity-driven migration of small objects are full of interest for both scientific and engineering communities, and a critical review is thereby presented. The small objects mentioned here deal with the non-deformable objects, such as particles, rods, disks and metal sheets; and besides them, the soft objects are considered, such as droplets and bubbles. Two types of interfaces are analyzed, i.e., the solid-fluid interface and the fluid-fluid interface. Due to the easily deformable properties of the soft objects and distorted interfacial shapes induced by small objects, a more convenient way to obtain the driving force is through the potential energy of the system. The asymmetric factors causing the object migration include the asymmetric configuration of the interface, and the difference between the interfacial tensions. Finally, a simple outlook on the potential applications of small object migration is made. These behaviors may cast new light on the design of microfluidics and new devices, environment cleaning, oil and gas displacement and mineral industries.