Finite-difference time-domain (FDTD) method with non-homogeneous cells filled with voxels

With the objective of reducing the overall number of FDTD cells in applications where the objects of interest are given as sets of voxels, as in bio-electromagnetism, a subcell technique is introduced to allow the FDTD method to account for non-homogeneous cells composed with voxels of different permittivity's. Numerical experiments with dielectric objects are reported to illustrate the effectiveness and the limitations of the method.