  The frequency of a wave is a crucial parameter to understanding its
propagation to a structured medium. While metamaterials can be designed to
focus or steer deformations or waves toward a specific location, wave steering
toward multiple targeted locations at different frequencies remains
challenging. Here we show that pruning of random elastic networks allows
realizing such multi-objective, multi-frequency acoustic steering. Our study
opens up a viable route to the rational design of multi-frequency acoustic
metamaterials.
