The experiment’s imaging system used a RedLake HG-XL high-speed camera from DEL Imaging Systems. This 1.7MPixel camera features a CMOS image sensor, 32GBytes of inbuilt record time memory and MotionCentral software, which has low-light dynamic range enhancement for color and monochrome imagers to enable the camera to see in dark or overexposed images. For its optics, it used a Sigma 180 F.2 APO Macro lens and a Vitacon 2X Auto Teleconverter.
An observation platform enabled the researchers to view the drops from the top. Glass surfaces were treated with 3-aminopropyltriethoxysilane (APTES) to achieve contact angles in the range. Contact angles were measured using static images of the drops, according to the research paper. From there, a metal mesh with 50 µm weave was fixed under the glass to allow the deformations of the patterns to be identified from the top view.
Below the mesh and glass platform, LED lights were used to pass light through the mesh in order to be refracted by the drop’s surface and reflected into the camera by a set of mirrors . This conveyed a deformed mesh pattern to the computer, which enabled the visualization of the deformation of the drop’s surface.
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