Optimize multilayer matching layer design for tone-burst underwater acoustic transducers

Abstract

In this study, a theoretical model has been constructed to address the optimization of matching layers for tone burst excitation underwater acoustic transducers and to investigate the functional mechanism change of matching layers. Single, double, and triple matching layers are attached to piezoelectric composite plates, and tone burst signals with a different number of burst-cycles are applied. Acoustic pressure function ( Sp) and acoustic pressure transient response (PTR) are compared among these transducers. The results demonstrated that when the cycle number M ≤ 2, more matching layers lead to shorter ringdown with similar PTR amplitude. Since the objective is for better axial resolution, three matching layers have noticeable advantage, whereas for the case of M > 5, far detection distance is the main objective, and more matching layers caused the decrease in PTR amplitude. Besides, matching layers become part of the resonance structure; they do not serve as a transmission medium anymore. Therefore, the transducer with single matching is optimal for the long tone burst excitation. For the case of 2–5 cycle excitation, one may use double matching layers, which has a balance between the transmitting voltage response amplitude and bandwidth. With the increase in M, the role of matching layers changes from a bridging transmission medium to amplifying vibration velocity and introducing additional vibration modes to broaden the bandwidth.

A Conformable Ultrasound Patch for Cavitation‐Enhanced Transdermal Cosmeceutical Delivery

“…No backing or matching layers are added to the PZT‐D as the objective of the design is to create large undamped peak pressures at a single driving frequency very close to the PZT‐D surface, rather than maximize the energy transfer over a large frequency bandwidth and decrease the Q ‐factor, as is desirable for imaging transducers. [ 52 ] Four PZT‐Ds are then arranged in a 2×2 array configuration with a center‐to‐center separation of 20 mm along with the serpentine metal (copper, Cu) electrodes that establish their electrical connections. The system is placed in a custom 3D printed poly(lactic acid) mold and fully encapsulated in a 2 mm‐thick PDMS layer.…”

“…The design and mechanical properties of the piezoelectric components and polymer encapsulation should be tailored for better biomechanical integration with soft facial skin. [81,82] Further, dual-frequency ultrasound [83] in conjunction with heavy matching layers [52] can be applied alternatively to nucleate, grow and collapse the bubbles using the distinct effects achieved with each mode as seen in Video S5, Supporting Information, and improve the abrasive and convective action of the bubbles. Finally, the issue of heat generation within the patch can be addressed through various routes: 1) shortening the duty cycle or total ultrasound application time, and 2) adding heat-sinks in the form of a metallic or conductive polymeric mass on the backing of the PZT-Ds to dissipate the heat to the surrounding air.…”