Detection of nanobubble generation and stability by a SOI nanophotonic ring resonator

Studies on physical aspects of nanobubbles, i.e., nanoscopic soft domains at the liquid-solid interface, have been increasingly undertaken in the past few years. On the technical application side, specifically in the field of microand nanofluidics, it has been conjectured that nanobubbles are responsible for various phenomena associated with the liquid-solid interface, such as liquid slippage at walls, nanometer-scale anomalous attraction of hydrophobic surfaces, or the stability of colloidal systems. More fundamentally, nanobubbles are a puzzling object, i.e., the existence of nanobubbles violates classic thermodynamic laws: According to the experimental data, these bubbles have a radius of curvature smaller than 1 micron, and therefore they should dissolve on timescales of mini-seconds, due to a large Laplace pressure inside of the bubbles. In marked contrast, the experiments reveal that nanobubbles are stable for periods as long as some hours!