Figure 6.
Localized mechanical modulations at distinct surfaces induce characteristic folds of shallow V-shape or deep U-shape. The cells at the center (Nc = 5, orange) of the sheet (N = 13) are modulated at the apical (A) or basal-lateral (B) surfaces. The flat sheet at the lower-right corner is generated with same parameter values as those in Fig. 1. (C) Quantification of epithelial fold morphology (gray) by the geometry of apical surface (red). (D and F) The local geometry, such as the V- and U-shapes, is characterized by the curvature κ = 1/Rc. (E and G) The deep (D) and shallow (S) global fold morphology is quantified by the aspect ratio γ = Da/Wa. The value Δq with q = ao, Ka, λb, and λℓ measures the mechanical differential between the central and the surrounding cells. Results for the cuboidal and squamous sheets are provided in Fig. S5. To see this figure in color, go online.