High-speed Atomic Force Microscope for Research on Dynamics at the Solid-liquid Interface

Atomic force microscopy (AFM) is a technique that makes it possible to observe surface profiles of an object in any environment, including atmosphere or under water, and at as high a spatial resolution as nanometer resolution (a nanometer is one billionth of a meter). Traditional AFM microscopes, however, would take 5-10 minutes to acquire an image, making it difficult to make a real-time observation of an object that changes its shape. Through industry-academia collaboration, Kao has introduced high-speed AFM technology that is capable of acquiring an image in as fast as several tens of milliseconds, to understand dynamic changes in form at a nanometer resolution, in its effort in the research on dynamics at the solid-liquid interface. Existing studies reported that a surfactant is stable in a globular micelle form at a specific salt concentration whereas its structure changes to wormlike micelles when it is adsorbed to the surface of mica, which creates electric interactions. Kao was the first to successfully observe this process, with the help of the high-speed AFM technique (Chem Commun 47 (2011) 4974).

As this analytical technique enables direct visualization of form changes at the solid-liquid interface, Kao has been pursuing the development of applications to a wide range of research objects, anticipating that it will shed light on the nature of expression of function at the interface level.