Flexible Piezoelectric Wave-Based Sensor: Numerical Analysis And Validation

Abstract

The demand for acoustic wave-based devices has been rapidly increasing in the aerospace, chemical, and biological fields due to their versatility towards sensing measurands. This paper explores the characteristics and effectiveness of acoustic wave-based two-port sensors designed with bidirectional IDT electrodes placed in different configurations, such as surface mounted or embedded inside the substrate, through numerical and experimental analysis. The numerical study involves 3D modeling of the sensor design to investigate wave characteristics by utilizing time-domain, i.e., time delay and wave patterns, and frequency-domain analysis, i.e., scattering parameter study. The sensor made of polyvinylidene fluoride polymer is modeled to ensure the concordance between the theoretical and numerical results as well as a preliminary experimental result obtained from transparent piezoelectric films. The coupling of modes theoretical model is used to obtain the device’s frequency response by a transmission matrix cascading technique. These investigated results will stand as guidance and facilitate defining an approach that can predict the behavior of the sensor with a specific design under different operating environments and expand its viability towards multi-functional devices that are reliable and sensitive to intended measurands.

On the performance of PVDF based piezoelectric sensor with microstructures

“…Finite element modeling allows appropriate optimization of sensor performance with added microstructures conveniently before fabrication, which can be validated using experimental results. In this work, PVDF substrate with added microstructure shapes is simulated numerically using a COMSOL Multiphysics tool 18,19 . All the required mechanical and piezoelectric material properties related to the physics used for substrate (PVDF), electrode (gold), and microstructures (acrylic plastic -material similar to Nanoscribe IP-S resin printed during the experiment) are assigned to respective designed domains, as listed in Table 2.…”

Wave-based sensor responses with embedded electrode layouts

“…The numerical analysis includes scattering parameter and voltage response in frequency and time domains. Compared to the surface deposited IDTs, embedding the electrode demonstrates an enhancement in sensitivity due to higher piezoelectric coupling [12][13][14] , which also protects the IDT structure from the external environment. The sensitivity of each IDT layout towards mechanical strains is quantified using an initial strain model with varying mechanical strain concentrations.…”