Acoustic wave manipulation

A device for manipulating an incident acoustic wave to generate an acoustic output comprising:

• an M×N array of unit cells, at least some of said unit cells being configured to introduce time delays to an incident acoustic wave at the respective positions of the unit cells within the array of unit cells, such that said plurality of unit cells define an array of time delays to thereby define a spatial delay distribution for manipulating an incident acoustic wave to generate an acoustic output,
• wherein the M×N array of unit cells includes a plurality of different types of unit cells, and
• wherein the M×N array of unit cells includes a selection of unit cells comprising one or more unit cells including a substantially labyrinthine or meandered structure that determines the respective time delay for the unit cell.

A device for manipulating an incident acoustic wave to generate an acoustic output comprising:

• an M×N array of unit cells, at least some of said unit cells being configured to introduce time delays to an incident acoustic wave at the respective positions of the unit cells within the array of unit cells, such that said plurality of unit cells define an array of time delays to thereby define a spatial delay distribution for manipulating an incident acoustic wave to generate an acoustic output,
• wherein the M×N array of unit cells includes a plurality of different types of unit cells, and
• wherein the M×N array of unit cells includes a selection of unit cells comprising one or more unit cells comprising a multi-slit, helical, coiled, or Helmholtz-resonator type structure.