Acoustic modes in 2-dimensional self-similar composite plates

We present the first experimental investigation of a Sierpinski carpet structure. This was constructed from piezoelectric square plates embedded in a polymer matrix according to a 4^th generation Sierpinski carpet. The resonant frequencies and vibrational displacement patterns have been measured. Experimental evidence for the existence of localised modes, together with a simple model for the estimation of the spectral density of states d_s, are presented