Figure 5
The sample layer is sealed between two polymer films by compressing the two films together against an underlying O-ring. As the O-ring compresses, the films are pulled laterally outwards over the rounded corner of a raised boss surrounding the window in the base plate. The surface of this boss projects 0.50 mm into the opening in the cover plate. Stretching helps remove any residual wrinkles in the films. The cover and base plate are both 2.50 mm thick, the films typically 2–6 µm thick and the sample layer typically 20 µm thick. |