Abstract: Phononic crystal wave structures and methods of making same are discussed in this application. According to some embodiments, an acoustic structure can generally comprise a phononic crystal slab configured as a micro/nano-acoustic wave medium. The phononic crystal slab can define an exterior surface that bounds an interior volume, and the phononic crystal slab can be sized and shaped to contain acoustic waves within the interior volume of the phononic crystal slab. The phononic crystal slab can comprise at least one defect portion. The defect portion can affect periodicity characteristics of the phononic crystal slab. The defect portion can be shaped and arranged to enable confinement and manipulation of acoustic waves through the defect portion(s) of phononic crystal slab. Other aspects, features, and embodiments are also claimed and described.