  The ability to control electromagnetic fields, heat currents, electric
currents, and other physical phenomena by coordinate transformation methods has
resulted in novel functionalities, such as cloaking, field rotations, and
concentration effects. Transformation optics, as the underlying mathematical
tool, has proven to be a versatile approach to achieve such unusual outcomes
relying on materials with highly anisotropic and inhomogeneous properties. Most
applications and designs thus far have been limited to functionalities within a
single physical domain. Here we present transformation optics applied to
thermoelectric phenomena, where thermal and electric flows are coupled via the
Seebeck coefficient and Joule heating is taken into account. Using laminates,
we describe a theoretical thermoelectric cloak capable of hiding objects from
thermoelectric flow. Our calculations show that such a cloak does not depend on
the particular boundary conditions and can also operate in different single
domain regimes. These proof-of-principle results constitute a significant step
forward towards finding unexplored ways to control and manipulate coupled
transport.
