Since most of the MVD is made up of four-silicon C-cages, it was important to note any differences between the four and six-silicon cages. Figure 8a shows the percent change in width for a four-silicon C-cage which has been coated with Parylene. It indicates that the width that had no silicon glued to it (See figure 5), expands as if it were a bare cage. The width with silicon has its expansion constrained again by about a factor of two. This is different from the six-silicon cage that has all widths constrained by the silicon. As the mechanical tolerance was defined in order to prevent silicon wafers from touching, the fact that the sections of the C-cage without silicon expand more than the sections with silicon is not a concern. In addition, neither case exceeds the -0.4% mechanical tolerance.
Figure 8b shows that the change in length is significantly different between the four and six-silicon cages. While the six-silicon cage contracts at low humidity, the four-silicon cage expands at low humidity and visa-versa for high humidity. This is due to the geometry of the four and six-silicon cages and how the presence of the silicon wafers influence the behavior of the cages in a changing environment. The four and six-silicon cages will be located relative to each other via light-weight tubes. The stresses caused by the movements of the cages in length with the changing environment are well within the elastic limits of the assembled support structure components.