(a) Transmembrane potential at the poles θ = 0, π calculated from Eq. 30, and (b) interior electric field calculated from Eq. 49 for a spherical shell with different membrane thickness, x = 5 × 10−4 and x = 10−3, in a uniform AC electric field. Λ = 0.5, S = 1.001, Cm = 0.025/x, Gm = 0.