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This study presents an advanced two‐step hot‐pressing process for fabricating the 1‐3 type Pb(ZrTi)O3/poly(vinylidene fluoride‐trifluoroethylene) (PZT/P(VDF‐TrFE)) piezoelectric composite sheets, demonstrating significant potential for nondestructive evaluation and information storage applications. The engineered columnar architecture within these composites induces a two‐phase clamping effect, which, upon polarization, facilitates the elongation of PZT and suppresses its lateral vibrations, thus enhancing the electromechanical coupling effect as verified by COMSOL simulations. A notable dielectric constant of 2200 at 100 Hz and a coupling coefficient of 0.725 was achieved with specific geometric modifications to the PZT/P(VDF‐TrFE) sheets. These findings suggest that P(VDF‐TrFE) as a polymer matrix exceeds the performance of conventional epoxy matrices, offering a novel approach to designing 1‐3 type piezoelectric composites. Highlights: P(VDF‐TrFE) effectively drives the elongation strain of internal PZT columns.COMSOL simulation clarifies the clamping effect of piezoelectric P(VDF‐TrFE).PZT/P(VDF‐TrFE) shows a higher kt of 0.725 than that of pure PZT samples. [ABSTRACT FROM AUTHOR]

A 1-3 type poly(vinylidene-trifluoroethylene)/lead zirconate titanate (P(VDF-TrFE)/Pb(Zr0.52Ti0.48)O3) piezoelectric composite is prepared using a two-step hot-pressing method, showing a considerable dielectric constant (εr ~ 4614) and a very low dielectric loss factor (tanδ) of 0.05 and at 100 Hz are obtained in PZT/P(VDF-TrFE) sheet with a thickness of 1.2 mm. Because the polarized P(VDF-TrFE) has a clamping pressure on the engineered columnar architecture by the inverse piezoelectric effect, the elongation of PZT is improved by suppressing its lateral vibrations, which is well expressed by COMSOL simulations. As such, an attractive electrical coupling coefficient (kt) of 0.733 is achieved with specific geometric modifications to the PZT/P(VDF-TrFE) sheets. These findings indicate that piezoelectric P(VDF-TrFE) to replace conventional epoxy resin as the polymer matrix offers a route to construct 1-3 type piezoelectric composites. [ABSTRACT FROM AUTHOR]

A lead‐free tetragonal‐phase (Ba0.94Ca0.06)(Ti0.95Zr0.05)O3 (BCTZ) micro sheet is prepared by molten‐salt growth method, which exhibits a polarizing behavior of relaxor ferroelectricity and possesses a high dielectric constant (εr) of ~2400. Subsequently, the BCTZ sheet is evenly doped into ferroelectric copolymer P(VDF‐TrFE)55/45 mol% with different mass fractions, and the flexible BCTZ/P(VDF‐TrFE) composite films are prepared using a conventional solution casting process. εr of BCTZ/P(VDF‐TrFE) increases with the mass content of BCTZ, and reaches 23.8 in 20 wt% BCTZ sample. Meanwhile, at a high electrical field of 30 MV/m, the strain and electric field of BCTZ/P(VDF‐TrFE) are in the opposite direction, indicating a negative value of piezoelectric strain coefficient (d33) caused by inverse piezoelectric effect. In addition, d33 of different BCTZ/P(VDF‐TrFE) films are fitted using a strain‐electrical field curve, which firstly increases and then decreases with increases in BCTZ content. As such, a high d33 of −47.3 pC/N is obtained in BCTZ/P(VDF‐TrFE)15/85 wt% film. Thus, this research concerning the inverse piezoelectric effect may provide a reference for designing a piezoelectric composite using in transducers and actuators. [ABSTRACT FROM AUTHOR]

It is well thought that the performance of polyvinylidene fluoride trifluoroethylene [P(VDF-TrFE)] is better than that of oriented polyvinylidene fluoride (oriented PVDF). But the harsh fabrication process or poor stability of P(VDF-TrFE) polymer limits its mass production. Therefore, it is worth making a comparative property assessment of PVDF and P(VDF-TrFE) piezoelectric polymers from the point of view of the practical application. In this work, we have used the oriented PVDF and P(VDF-TrFE) films to prepare an array of flexible piezoelectric and pyroelectric hybrid energy conversion devices. The responses of devices to different scenarios and environments were investigated. It was found that the two energy conversion devices can convert various forms of energy from the external stimulus conditions to get the output electrical signals. However, the two conversion devices exhibited different signal responses to different forms of external stimuli, which provides a reference for the choice of device materials in practical applications. It was confirmed that the oriented PVDF film fabricated by the simple and economical method has also great potential applications as wearable and electronic touch screens and medical monitoring devices. [ABSTRACT FROM AUTHOR]

Recently, for their advantages of lightweight, easy-shaped, good corrosion resistance, biocompatibility, etc., a series of flexible poly (vinylidene fluoride)-based (PVDF-based) piezoelectric composites have been proposed for use in self-powered electronic devices, such as piezoelectric nanogenerators, sensors, wearable electronic units, etc. In this review, we classify the polymer-based piezoelectric composites, combine their preparation method, filler type, structure, and performance, etc., and explain in detail the effects of different preparation methods and filler types on the piezoelectric properties of the composites. Then, the influence of composition, structure, and forming method on the piezoelectric and energy-transforming performances are investigated. Finally, the development trends of these PVDF-based piezoelectric composites are prospected. This review may provide a reference for the academic and application of the polymer-based piezoelectric composites in energy transfer-related and harvesting-related areas. [ABSTRACT FROM AUTHOR]

Piezoelectric self-powered electronic devices can convert ambient mechanical vibrations into electrical energy in an environmentally friendly manner, significantly alleviating the scarcity of non-renewable sources. This work prepares an one-dimensional potassium sodium niobate micro rods (1D KNN MRs) using the molten salt - topological chemical reaction method, showing the significant advantages over 0-dimension (0D) nanoparticles due to its anisotropy. Simultaneously, KNN MRs are introduced into poly (vinylidene fluoride-trifluoroethylene) to form a KNN MRs/P(VDF-TrFE) piezoelectric composite, effectively facilitating the piezoelectric β -phase in P(VDF-TrFE) film, and contributing to a high remnant polarization (P r ∼12.3 μC/cm2) at 125 MV/m and a high piezoelectric constant (d 33 = −28 pC/N). Interestingly, a piezoelectric sensor assembled by KNN MRs/P(VDF-TrFE) composite shows a considerable piezoelectric output of 17.6 V at a scene of 2.5 MPa stress, offering a novel route for designing the optimum ceramic/polymer combinations suitable for mechanical energy conversion and energy harvesting. [Display omitted] [ABSTRACT FROM AUTHOR]

To clarify the influence of various molar concentrations of vinylidene fluoride (VDF) on the piezoelectric and acoustic emission (AE) reception performances of poly(vinylidene fluoride-trifluoroethylene) [P(VDF-TrFE)] sensors, we systematically investigated the crystal structures and the dielectric and ferroelectric properties of P(VDF-TrFE) films with different compositions of VDF and TrFE monomers and found that low proportion (<30 mol%) TrFE as a wedge inserted into molecular chains of P(VDF-TrFE) will not only improve the fraction of regular β-phase crystal grains but also decrease the dielectric constant (εr) of these copolymers, which favors the piezoelectric voltage coefficient (g33) of this P(VDF-TrFE) film. As such, a considerable remanent electric polarization (Pr ~ 11.4 μC cm2) under 200 MV/m and a large piezoelectric coefficient (d33 ~ -25 pC/N) are obtained in P(VDF-TrFE) 80/20-mol% films. It is worth noting that a sensor made from P(VDF-TrFE) 80/20 mol% shows an attractive AE reception property of approximately 84 dB, a high signal voltage of above 10 mV from time-domain analysis, and a large signal voltage of above 4 mV from frequency-domain analysis, which are close to standard lead zirconate titanate (PZT) sensors. Considering its unique characters of flexibility, no required stretching, easily shaped, having high thermal Faille temperatures (Tc ~ 135.7 ∘C), etc., P(VDF-TrFE) piezoelectric film is considered a promising material for sensors, actuators, and energy transfer units. [ABSTRACT FROM AUTHOR]

Polyvinylidene fluoride-trifluoroethylene [P(VDF-TrFE)] polymer materials possess good piezoelectric properties, leading to their use in many practical applications as sensors and transducers. However, pure P(VDF-TrFE) exhibits relatively brittle properties and low thermal resistance. In this work, porous P(VDF-TrFE)/PBDMS flexible materials were designed by embedding a low Young's modulus polyborosiloxane (PBDMS) into the [P(VDF-TrFE)] structure. These P(VDF-TrFE)/PBDMS porous polymer materials exhibit excellent flexibility and piezoelectric response to external stimuli such as bending, shock, vibration, and breathing. The output voltage of these polymer materials can be maintained at a high value of 8.25 V over 6600 cycles of continuous vibration. In addition, the porous polymer materials generate a transient voltage response when in contact with small droplets of water at different temperatures. This work provides a novel approach for designing lightweight and wearable piezoelectric sensors for potential applications in human motion monitoring, mechanical vibration monitoring, and pyroelectric devices. [Display omitted] • A porous structured P(VDF-TrFE)/PBDMS composite film was designed to overcome the brittleness of the pure P(VDF-TrFE). • The composite film exhibits an excellent flexibility and piezoelectric sensing to the external stimuli. • A high output voltage of 8.25 V was constantly realized for the composite film over 6600 cycles of continuous vibration. • This work provides a strategy of designing lightweight and wearable piezoelectric sensors for human motion monitoring. [ABSTRACT FROM AUTHOR]