68
mean value for log (L/W) for the smooth areas around zero, but with a large standard
deviation.
Interaction Plot Data Means for log (L/W)
Fibronectin Coated Feature
10
20
0.3 5
-smooth
0.2
0.0
0.0 - - - - - - --
I I
1.5 5.0
Depth
Figure 4.4 Interaction plot representing the change in contact guidance with depth and
feature width for fibronectin coated silicone elastomer.
Figure 4.5 and Figure 4.6 are main effects and interaction plots for plasma treated
unmodified elastomers generated by Minitab. These are the same plots as Figure 4.3 and
Figure 4.4, which are treated with FN. As can be seen in Figure 4.5, the difference
between the feature widths is not as obvious, and the effect of the depth on the alignment
does not play as large a role from 1.5 .im to 5 rim, as confirmed by the small slope.
A two-way ANOVA comparison on plasma treated unmodified elastomer
comparing the effects of feature size and depth show that when including the smooth
areas in the analysis, the feature size is a very significant contributor to variance (p <
0.0001) while depth is not a significant influence. By removing the smooth terms and