A model is proposed to predict the electroelastic moduli of 0-3 connectivity piezo-composites from which parameters such as longitudinal wave velocity and thickness mode coupling factor can be deduced. The composite, a polymer loaded with ceramic particles, represented by unit cell, matrix manipulation shown practical way perform generalization series parallel analysis used for 2-2 composites. anisotropy phase taken into account, its effect on properties composite shown. then optimize...

A Phononic Crystal (PC), constituted of a homogeneous piezoelectric plate covered by 1D periodic arrangement thin metallic electrodes on both surfaces, is studied. The application Electric Boundary Conditions (EBCs) the enables propagation control ultrasonic guided waves in PC. band structure investigated for different EBCs: are either at floating potential or they alternately short-circuited and potential. In latter case, Bragg gap appears fundamental S0 Lamb mode. These results verified...

We investigated the innovative processing of poly(vinylidene fluoride-trifluoroethylene) P(VDFx-TrFE1-x) (x = 83 mol. %) by inkjet printing to deliver uniform and thickness-controlled layers on silicon substrates. Here, we provide detailed steps optimize film deposition conditions. The thickness coupling factor for a P(VDF-TrFE) around 11 μm thick was 22%, demonstrating good electromechanical performance after poling. These multilayer structures were specifically high-frequency,...

A screen-printed PZT thick film with a final thickness of about 40 mum was deposited on porous substrate to obtain an integrated structure for ultrasonic transducer applications. This process makes it possible decrease the number steps in fabrication high-frequency, single-element transducers. The substrates allow high acoustic impedance and attenuation be obtained, satisfying backing requirements medical imaging. piezoelectric films deliver electromechanical performance, comparable that...

We demonstrate numerically and experimentally the opening of a locally resonant bandgap in an active phononic crystal (PC) made homogeneous piezoelectric plate covered by 1D periodic array thin electrodes connected to inductive shunts. The application electrical boundary conditions (EBCs) enables at will tailoring dispersion properties PC plate, thus leading control propagating guided elastic waves plate. Depending on nature EBCs, several bandgaps open up, most important being Hybridization...

A model previously developed for pure 0-3 connectivity piezocomposites has been extended to 3-3 connectivity. This matrix method allows the prediction of effective electroelastic moduli a piezocomposite according its It is used optimize composite performance by choosing optimal constituents each phase. simple combination results and connectivities proportion be defined in highly loaded piezocomposites. theoretical analysis evaluate proportions five samples. The values obtained are shown...

Detection of high-order nonlinear components issued from microbubbles has emerged as a sensitive method for contrast agent imaging. Nevertheless, the detection these high-frequency components, including third, fourth, and fifth harmonics, remains challenging because lack transducer sensitivity bandwidth. In this context, we propose new design imaging based on simple fabrication process The is composed two elements: outer low-frequency (LF) element was centered at 4 MHz used in transmit mode,...

We studied the effect of porosity and pore morphology on functional properties Pb(Zr0.53Ti0.47)O3 (PZT) ceramics for application in high frequency ultrasound transducers. By sintering a powder mixture PZT polymethylmetacrylate spherical particles (1.5 10 μm) at 1080°C, we prepared with ∼30% interconnected micrometer sized pores predominantly ∼8 μm pores. The acoustic impedance was ∼15 MRa both samples, which lower than dense PZT. attenuation coefficient α (at 2.25 MHz) higher (0.96 dB mm− 1...

In this work, the effects of thermal annealing at 500 °C on aerosol-deposited 0.65Pb(Mg1/3Nb2/3)O3-0.35PbTiO3 thick films stainless-steel substrates are investigated using two complementary methods high and low applied external electric fields. The first one is positive up negative down method, which allows us to obtain information about switching non-switching contributions polarization. It shows that as-deposited film ferroelectric before annealing, since it has a contribution After both...

Ferroelectric perovskites are pivotal in diverse technological applications; however, a gap persists our comprehension of their mechanical properties, emphasizing the need for additional exploration. In present study, we report on nanomechanical behavior BiFeO3 ceramics force range between 200 μN and 2 mN, including evolution hardness reduced Young's modulus from (9.9 ± 0.4) GPa (113.7 6.9) GPa, respectively, with increasing force. A sequence plastic-deformation mechanisms under cube-corner...

In a high volume fraction particle-loaded piezocomposite, some ferroelectric particles appear to be in contact, as 3-3 connectivity material; others are isolated the polymer matrix, pure 0-3 material. Such material can considered composite of composites characterized by 3-3(0-3) connectivity. This paper follows two that have described matrix method calculate all effective parameters and piezocomposites. These previous models used obtain properties composite. A proportion is introduced,...

A new hybrid finite-difference (FD) and pseudospectral (PS) method adapted to the modeling of piezoelectric transducers (PZTs) is presented. The time-dependent equations propagation are solved using PS while electric field induced in material determined through a FD representation. purpose this combination keep advantages both methods one model: adaptability representation model elements with various geometries materials, low number nodes per wavelength required by method. This approach...

Abstract Piezoelectrics are key materials for energy conversion, example in ultrasound transducers and harvesters. This work presents the synthesis characterization of lead-free piezoelectric composition (Li 0.06 (K 0.52 Na 0.48 ) 0.94 )(Nb 0.71 Ta 0.29 )O 3 doped with 0.25 mol% Mn (KNNLTM) as textured ceramics. Templated grain growth from NaNbO platelet templates aligned by tape casting was used to introduce texture, after sintering 14 h at 1100 °C this produced up 84% (100) pc orientation....

The objective of this work is to provide an accurate model the lateral resonance modes in 1–3 piezoelectric composite materials. These materials are widely used ultrasonic transducers and lowest mode frequency gives upper limit for usable transducer bandwidth. Considering propagation purely transverse waves a 2-D periodic medium infinite thickness, two different approaches obtaining solutions presented compared. first approach based on use Bloch theory. second straightforward method (a...

This work presents the fabrication of a 30 MHz, linear-array transducer based on KN, 1–3 piezocomposite. Performances were characterized and compared to PZT-based linear array with similar structure. The composites designed minimize lateral modes vibration which can severely degrade imaging performances. Fabrication steps optimized achieve 40 MHz resonant frequency in air composite thickness 69 µm. measured coupling factor was around 50%. A 128-element, then fabricated 100 µm pitch 1.5 mm...

This numerical study compares the acoustic performance of three focalization principles (using a concave piezoelectric element, lens, or Fresnel Zone Plate) for high-frequency (50 MHz) PVDF-based single-element transducer. A pseudo-spectral time-domain method was used to simulate ultrasound wave propagation in water and deduce properties focal zone. The distance investigated between 10-20 mm with step 1 mm. external diameter identical all configurations fixed at 6 results showed similar...

Lead–zirconate–titanate ( PZT ) thick films for high‐frequency ultrasound applications were fabricated using an electrophoretic deposition EPD process. The powder was synthesized from constituent oxides at close‐to‐room temperature by mechanochemical activation followed calcination 700°C. Homogeneous with a thickness of ~30 μm and density ~80% produced ethanol‐based colloidal suspensions containing PbO particles that deposited constant‐current mode on platinized alumina substrate sintered in...