Nanobubbles on the immersed substrates

Surface nanobubbles is one significant discovery in interfacial physics in recent decade. Scientists have confirmed their existence since the surface nanobubbles were observed by using atomic force microscope (AFM). Studies of nanobubbles' properties and influence factors have been developed deeply because of its potential applications in microelectromechanical system (MEMS), micro biochemical system, hydrodynamics, surface science, etc. The stability (abnormal longevity) of nanobubbles, however, is still one of open questions. The latest research results of nanobubbles' stability are mainly reviewed in this paper, including line tension theory, dynamic balance theory, impurity theory and Knudsen gas type theory. Additionally, the applications, influences and formation of nanobubbles are sketchily introduced. In the end, we give some suggestions on what still needs to be done to obtain a full understanding of nanobubbles.