Theoretical simulation on Zn microelectrodes. (A) The simulations of potential, electric field distribution, and energy distribution of (top) concentric circle structured, (middle) straight interdigital, and (down) circular Zn-PANI microbatteries [79]. (B) FEA of a nonplanar 3D-printed electrode and a conventional 2D sheet-type electrode on non-developable surfaces. The left scheme depicts the non-developable surface with non-zero Gaussian curvature [71]. (C) Optical images (up) and corresponding strain maps in the stretching direction (down) of an interdigitated current collector under different global tensile strains. The contour of the current collector at 0% strain is shown in the dashed line [101]. Reproduced with permission.