  Inspired by recent graded metamaterials designs, we create phononic arrays of
micro-resonators for frequency signal amplification and wave filtering.
Leveraging suspended waveguides on a thick silicon substrate, we hybridize
surface Rayleigh and Lamb flexural waves to effectively achieve phononic signal
control along predefined channels. The guided waves are then spatially
controlled using a suitable grading of the micro-resonators, which provide high
signal-to-noise ratio and simultaneously create phononic delay-lines. The
proposed device can be used for sensing, wave filtering or energy harvesting.
