  Transformation methods have stimulated many interesting applications of
manipulating electromagnetic and acoustic waves by using metamaterials, such as
super-lens imaging and cloaking. These successes are mainly due to the
form-invariant property of the Maxwell equations and acoustic equations.
However, the similar progress in manipulating elastic waves is very slow,
because the elastodynamic equations are not form-invariant. Here we show that
the expression of the elastodynamic potential energy can almost retain its form
after conformal mapping, if the longitudinal wave velocity is much larger than
the transverse wave velocity, or if the wavelength can be shortened by
converting the waves into surface modes. Based on these findings, it is
possible to design and fabricate novel devices with ease to manipulate elastic
waves at will. One example presented in this paper is an efficient vibration
isolator, which contain a 180-degree wave bender made of conventional rubbers.
Compared with a conventional isolator of the same shape, similar static support
stiffness and smaller damping ratio, this isolator can further reduce wave
transmissions by up to 39.9dB in the range of 483 to 1800 Hz in the experiment.
