Method of making acoustic devices with edge corrugation

A method of making an electronic device, comprising:

• forming or providing a printed circuit board that includes a substrate layer;
• forming or providing one or more piezoelectric microelectromechanical systems microphones via a process including (a) forming or providing a mold extending along a length and having one or more grooves in a top surface of the mold, the one or more grooves extending in a direction of the length of the mold to a distal end of the mold, (b) forming or depositing a structure having one or more piezoelectric layers over the top surface of the mold to define a beam with a proximal portion and a distal portion, the distal portion having a corrugated section including one or more grooves that correspond to the one or more grooves of the mold, (c) forming a gap in the structure to define two beams with free ends separated by the gap, (d) releasing the structure from the mold, and (d) leaving a part of the structure attached to a substrate in a cantilevered manner to form two cantilever beams having said free ends separated by the gap, the two cantilever beams configured to deflect independently of each other when subjected to sound pressure;
• and
• mounting the one or more piezoelectric microelectromechanical systems microphones on the printed circuit board.