  In this work, we present a practical design of quasi isotropic underwater
acoustic carpet cloak with pentamode microstructure. The quasi conformal
transformation is not only used to obtain the required parameters, but also
used to deform the retrieved regular pentamode material structure to the
desired carpet, during which the effective parameters can be considered as not
being affected too much. The nice and broadband cloak effect shows the success
of the design. This work will contribute to the experimental demonstration of
pentamode acoustic carpet cloak. Moreover, the technique in this work also can
be used to design arbitrarily shaped devices with microstructures.
