Fig. 2.

Modulating the size of patterned patches by controlling the swelling time. (A) The spacing ($W$) between neighboring creases is proportional to the swollen layer thickness ($H$), which is controlled by the swelling time ($t$). An effective diffusion constant ($D_{eff}=7.69\mathrm{\times }{10}^{-10}\hspace{0.17em}{\mathrm{m}}^{\mathrm{2}}/s$) for the swelling of the elastomer by the solvent can be obtained by plotting $W^2$ as a function of $t$. (B) Micrographs showing three different pattern sizes resulting from three different swelling times.