As ellipsometry capabilities gain wider publicity there is a remarkable interest in using the technique for unusual material characterizations. In the past decades, the possibility of non-destructive, contactless investigations regarding the structural and optical properties of free liquid surfaces has gained importance for both chemical and biological applications. To obtain high-accuracy ellipsometric measurements on liquid surfaces certain technical obstacles must be eliminated.

The first obvious difficulty stems from the presence of environmental vibrations which make the liquid surface oscillate in a way that the resulting surface waves scatter out the light upon reflection. The second problem is that the liquid surface is always horizontal (vid. spirit leveled), thus the incident plane must be aligned according to it.

In this study we present a solution for both above-mentioned problems by utilizing active pneumatic isolators. The capability of the method is demonstrated on bulk liquid samples of high purity distilled water, glycerol, and Polydimethylsiloxane (PDMS) and on liquid layer on liquid substrates (PDMS on glycerol).

If you want to know more about the possibilities of this unusual but cost-effective method, read the full article published in Thin Solid Films Journal at Science Direct! The complete study is available for free to read until 4^th February, 2023.