Figure 1
J. Prat-Camps et al./Autonomous Univ. of Barcelona

Field trip. Cylindrical shells with the right properties would expel magnetic field energy. Here, the field from a bar magnet within the shell on the left is pushed outward, increasing its strength in the exterior region. A second shell, on the right, captures the field passing through it and concentrates the field’s strength in this shell’s interior. This scheme could allow the transfer of magnetic energy with improved efficiency.