  We present a method to achieve one-way mode isolation in acoustic waveguides
by considering spatio-temporal modulation of material properties. Mode
conversion between symmetric and antisymmetric shear horizontal (SH) modes of
an unbounded plate acoustic waveguide is demonstrated using this method.
Analytical and numerical evidence for the possibility of mode conversion is
presented. Possible experimental implementation and applications for on chip
signal isolation in MEMS devices are also suggested.
