  Gradients in temperature and particle concentration fuel many processes in
the physical and biological world. In the present work we study a thermodynamic
engine powered by anisotropic thermal excitation (that may be due to e.g., a
temperature gradient), and draw parallels with the well-known principle of
impedance matching in circuit theory, where for maximal power transfer, the
load voltage needs to be half of that of the supplying power source. We
maximize power output of the thermodynamic engine at steady-state and show that
the optimal reactive force is precise half of that supplied by the anisotropy.
