Sound cloak to trap sound waves

    The idea is to develop an invisibility cloak that will trap sound waves, preventing the sound from leaving the material.
    The proof of concept 'cloak' will be a small, thin plate made up of rings of micro-structured polymer material that will resonate at different frequencies. Sound wave vibrations will follow a circular path around the plate, unable to leave the material.
    The cloak will differ from conventional noise protection devices in that the sound waves will be neither absorbed nor reflected.