###### Abstract  
Acoustic waves can be used for wireless telemetry as an alternative to situations where electrical or optical penetrators are unsuitable. However, the response of the ultrasonic transducer can be greatly affected by temperature variations, mechanical deformations, misalignment between transducers, and multiple layers in the propagation zone. Therefore, this work sought to quantify such influences on communication between ultrasonic transducers. The experimental measurements were performed at the frequency where power transfer is maximized. Moreover, there were four experimental models, each with its own performed setup. The ultrasonic transducers are attached to both sides of a 6 mm thick stainless-steel plate for configuring just one barrier. Multiple layers of transducers are attached to the outer side of two plates immersed in an acoustic fluid with a 100 mm thick barrier. In both cases, the S21 parameter was used to quantify the influence of the physical barrier because it correlates with the power flow between ports that return after a given excitation. The results showed that when a maximum deformation of 1250 \(\upmu\)m/m was applied, the amplitude of the S21 parameter varied around +0.7 dB. Furthermore, increasing the temperature from 30 to 100 \({}^{\circ}\)C slightly affected the S21 (+0.8 dB), but the signal decayed quickly for temperatures beyond 100 \({}^{\circ}\)C. Additionally, the ultrasonic communication with a multiple layer was found to occur under misalignment with an intersection area of up to 40%. None of the factors evaluated resulted in insufficient power transfer, except for a large misalignment between the transducers. Such results indicate that this type of communication can be a robust alternative, with a minimum alignment of 40% between transducers and electrical penetrators. Keywords:ultrasonic telemetry; elastic wave propagation; piezoceramic transducers; ultrasonic communication +
Footnote †: journal: Accepted: 25 August 2024  
these ultrasonic transducers are piezoelectric ceramics that emit and receive ultrasonic signals. Moreover, the system must be resonant to be efficient, and the best impedance match between emitters and receivers must always be sought. However, changes in ambient temperature, mechanical stresses, and strains generated in the wall, as well as misalignment between the ultrasonic transducers, tend to affect the quality of the communication through the channel. Nevertheless, as can be inferred from the ensuing literature review, although these effects have been separately studied, there are still questions regarding the severity of their combined effects. We address those in the present contribution. [PERSON] et al. [3] have theoretically demonstrated the feasibility of transmitting energy through a metallic barrier using piezoceramic transducers. Following their work, [PERSON] et al. [4] employed numerical simulations to investigate how dielectric, piezoelectric, and mechanical losses in the system affect its transfer efficiency, concluding that the adhesive layers that couple the UTs to the wall must play an important role in the overall system response. In an ensuing article, [PERSON] et al. [5] explored their prior results to examine three different options for bonding the UTs into the faces of the wall. Their experiments with conductive epoxy demonstrated a 40% efficiency in power transfer. They also analyzed nonlinear and thermal effects, proposing an operational envelope for their specific design. [PERSON] et al. [6] reported the design and characterization of a prototype for an acoustic-electric-feed-through capable of transferring 1 kW, with an efficiency of 88%, through a 5 mm thick titanium plate via ultrasonic waves.