The design and evaluation of additively manufactured piezoelectric acoustic transducers

Abstract

Ceramic additive manufacturing (AM) has been demonstrated as a capable method to fabricate piezocomposite acoustic transducers that exhibit augmented sensitivity, increased bandwidth, and controlled directivity by virtue of geometry. These improvements are intrinsic to the novel piezoelectric ceramic structure, which may be printed in forms that cannot be fabricated through conventional manufacturing methods. The AM process allows for functionally-graded apertures, 3-3 piezocomposite structures, and auxetic lattices which have been simulated, printed, and measured with compelling results. This presentation expands upon previous work completed through a collaboration between Lithoz America, LLC (Lithoz), MSI Transducers Corp. (MSI), and the MITRE Corporation (MITRE) to produce novel piezoelectric structures and validate acoustic and hydrostatic pressure performance of 1-3 piezocomposite structures under operationally relevant conditions. The presentation will encompass a discussion of Finite Element Analysis (FEA) of piezoelectric metamaterials conducted at MITRE, the lithography-based ceramic manufacturing (LCM) process of said structures at Lithoz, and empirical measurements of piezoelectric and acoustical specifications of the printed structures conducted at MSI. Finally, test data recorded at Woods Hole Oceanographic Institute (WHOI) will be shown, demonstrating the resilience of AM 1-3 piezocomposite under 10 000 PSI of hydrostatic pressure derived by means of in-situ electrical impedance measurements.