Fig. 3. Schematic diagram showing: (A) the geometry of the initial sphere; r₀ is the initial radius of the cell before inflation; (B) the geometry of the inflated sphere before compression; r_i is the radius of the cell after inflation; and (C) the geometry of a compressed sphere; η is the half‐distance between the probe surface and the plate, ρ is the maximum radius of the deformed wall and membrane. In compression, a typical point like A, at an angle ψ to the vertical axis of symmetry, moves to point B. The angle Γ identifies points that move to the edge of the contact region, which has radius r_c.