  Recent advances in metasurfaces have shown the importance of controlling the
bianisotropic response of the constituent meta-atoms for maximum efficiency
wavefront transformation. Under the paradigm of a bianisotropic metasurface,
full control of the local scattering properties is allowed opening new design
avenues for creating reciprocal metasurfaces. Despite recent advances in the
perfect transformation of both electromagnetic and acoustic plane waves, the
importance of bianisotropic metasurfaces for transforming cylindrical waves is
still unexplored. Motivated by the possibility of arbitrarily controlling the
angular momentum of cylindrical waves, we develop a design methodology for a
bianisotropic cylindrical metasurface that enables perfect transformation of
cylindrical waves. This formalism is applied to the acoustic scenario and the
first experimental demonstration of perfect angular momentum transformation is
shown.
