Nanoscale materials are nowadays widely used in many different modern technologies. Special attention is thus required for their characterization in order to optimize fabrication processes. However, current characterization systems which can achieve nanometric resolution over a large area and in three dimensions are few. Classical optical microscopy presents a resolving power limited by diffraction, making impossible the visualization of elements with a size under half the wavelength. Recently, several methods have thus been developed to overcome this limitation, among them microsphere-assisted microscopy. Indeed, using a transparent microsphere, a full-field image of the sample can be retrieved with a higher resolution than the diffraction-limit. In this paper, this new imaging technique is combined with phase-shifting interferometry in order to reconstruct the 3D surface of nanostructures. An enhancement of a factor of 4.0 in the lateral resolution is demonstrated while combining this with the nanometric axial sensitivity of interferometry. Results are shown of the topography of reference gratings as well as periodic Ag nano-dots on silicon and laser induced ripples in steel, spaced by a few hundred nanometres. A comparison of these results is made with those from SEM and atomic force microscopy. status solidi physica a Interference Microscopy www.pss-a.com

We have considered in this work the Wilhelmy plate tensiometer to characterize the wetting properties of two model surface textures: (i) a series of three superhydrophobic micropillared surfaces and (ii) a series of two highly water-repellent surfaces microtextured with a femtosecond laser. The wetting forces obtained on these surfaces with the Wilhelmy plate technique were compared to the contact angles of water droplets measured with the sessile drop technique and to the bouncing behavior of water droplets recorded at a high frame rate. We showed that it is possible with this technique to directly measure triple-line anchoring forces that are not accessible with the commonly used sessile drop technique. In addition, we have demonstrated on the basis of the bouncing drop experiments wetting transitions induced by the specific test conditions associated with the Wilhelmy plate tensiometer for the two series of textured surfaces. Finally, the tensiometer technique is proposed as an alternative test for characterizing the wetting properties of highly liquid-repellent surface, especially under immersion conditions.

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