Acoustic devices with directional reinforcement

A piezoelectric microelectromechanical systems microphone, comprising:

• a substrate;
• and
• a plurality of piezoelectric sensors movably coupled to the substrate, each of the piezoelectric sensors spaced apart from an adjacent piezoelectric sensor by a gap and including:
• a piezoelectric cantilever beam formed from one or more piezoelectric layers and having a proximal portion attached to the substrate and a distal portion that is continuous with the proximal portion and extends from the proximal portion to a free end of the beam, the beam extending in a first direction between the proximal portion and the free end, the distal portion of the beam having a corrugated section including one or more grooves formed in the one or more piezoelectric layers and that extend generally in the first direction, a thickness of the beam between a top piezoelectric surface and a bottom piezoelectric surface in a second direction perpendicular to the first direction being greater in the corrugated section than in a proximal end of the beam that is vertically aligned with and vertically adjacent to and attached to the substrate, and an electrode disposed on or in the proximal portion of the beam, the one or more grooves being recessed relative to the top piezoelectric surface and having a length greater than a width and a depth, the one or more grooves extending linearly along their length in the first direction, the corrugated section increasing a rigidity of the cantilever beam in the first direction without adding to a mass of the distal portion,
• the plurality of piezoelectric sensors being configured to deflect when subjected to sound pressure.

An audio subsystem, comprising:

• an audio codec;
• and
• one or more piezoelectric microelectromechanical systems microphones in communication with the audio codec, each microphone including:
• a substrate and a plurality of piezoelectric sensors movably coupled to the substrate, each of the piezoelectric sensors spaced apart from an adjacent piezoelectric sensor by a gap and including a piezoelectric cantilever beam formed from one or more piezoelectric layers and having a proximal portion attached to the substrate and a distal portion that is continuous with the proximal portion and extends from the proximal portion to a free end of the beam, the beam extending in a first direction between the proximal portion and the free end, the distal portion of the beam having a corrugated section including one or more grooves formed in the one or more piezoelectric layers and that extend generally in the first direction, a thickness of the beam between a top piezoelectric surface and a bottom piezoelectric surface in a second direction perpendicular to the first direction being greater in the corrugated section than in a proximal end of the beam that is vertically aligned with and vertically adjacent to and attached to the substrate, and an electrode disposed on or in the proximal portion of the beam, the one or more grooves being recessed relative to the top piezoelectric surface and having a length greater than a width and a depth, the one or more grooves extending linearly along their length in the first direction, the corrugated section increasing a rigidity of the cantilever beam in the first direction without adding to a mass of the distal portion.