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Piezoelectric accelerometers present higher sensitivities and better signal-to-noise ratios in comparison with piezoresistive and capacitive accelerometers. A micro-electromechanical system (MEMS) piezoelectric accelerometer was designed and manufactured with four L-shaped beams covered by Lead Zirconate Titanate (PZT) thin film with $1~\mu \text{m}$ in thickness which was deposited using sol-gel methods. The micro devices, whose size and the optimized PZT distribution were determined by theoretical and simulation analysis, were fabricated on the silicon substrate using PZT films working in the ${d}_{31}$ mode. Different from the conventional vertical crossbeam accelerometers, the designed structure devotes to the larger area piezoelectric film laid on L-shaped supporting beams with higher energy transferring efficiency for sensing. Then the chips of accelerometer were fabricated, and the proposed sensor was packaged on the printed circuit board (PCB). In addition, the microsphere was integrated in the center of the beams. Finally, the properties of the accelerometer were measured by vibration measurement system. The measuring results show that the initial sensitivity of the accelerometer is 28.14mV/g at 500Hz. The proposed piezoelectric accelerometer has high sensitivity and low resonance frequency, and the frequency response on each beam is consistent, providing a new structure for high-performance accelerometer. [ABSTRACT FROM AUTHOR]

Nanomechanical properties are extremely critical to the applications of flexible electric devices and energy harvester; however, the direct mechanical measurement of composite nanofibers is challenging and rarely explored. In this work, we apply an effective method to obtain the elastic modulus distribution of lead zirconium titanate (PZT)-doped polyvinylidene fluoride (PVDF) nanofibers via bimodal amplitude modulated-frequency modulated scanning probe microscopy (AM-FM SPM). All the samples exhibit obvious piezoelectric properties, and the mechanical properties are clearly enhanced through doping of PZT. Compared with pure PVDF nanofibers, the composite nanofibers with PZT doping show higher elastic modulus which indicates superior stability under the same bending condition. The enhancement of mechanical properties in composite nanofibers via filler doping pave a way to the design of stable and flexible sustainable energy harvesters. [ABSTRACT FROM AUTHOR]

Abstract In this study, we investigated the impact of electrodes on the structural, crystal orientation, and electrical characteristics of lead zirconate titanate [Pb(Zr 0.52 Ti 0.48)O 3 , PZT] thin films, that were deposited on Pt, Au, and LaNiO 3 (LNO) electrodes through sol-gel processes. The peak voltage, that is, the voltage corresponding to the maximum switching current point, was developed to depict the novel peak-drift electric characteristics in ferroelectric thin films. It increases in the positive ferroelectric peak voltage, and decreases in the negative peak voltage with an increase in the driving voltage amplitude. Based on space-charge-limited bulk conduction, we evaluated the peak-drift phenomenon, Schottky contact and their influences on the switching current. When polarization orientation is reversed, the Schottky contact disappears at one side of the PZT/electrode, and forms at the other side synchronously. Our results indicate that the formation of a Schottky contact affects the shape of the switching curves, and its disappearance influences the magnitude of the current characteristics. [ABSTRACT FROM AUTHOR]

Pb(Zr 0.3 Ti 0.7)O 3 - x mol% Mn (PZTM) (x = 0, 1, 2, and 3) thin films with high density and good crystallinity were obtained using a sol-gel method. Improved crystallization, domain, and ferroelectricity through controlling the lead/oxygen vacancies in Mn-doped lead zirconate titanate (PZT) thin films were investigated. Enhanced ferroelectricity and piezoelectricity were obtained in the 1 mol% Mn-doped PZT thin films. According to the Bragg equation, a small amount of Mn replaces the A-site (Pb2+) to achieve donor doping, which is conducive to the movement of domains and enhances the ferroelectric performance and piezoelectric coefficient. The pinning effect leads to reduced ferroelectric performance, which is caused by oxygen vacancies generated by Mn2+ replacing the B-site (Zr4+/Ti4+) during acceptor doping. The research results show that Mn doping is an effective method for improving the ferroelectric performance of PZT thin films. • The Mn contant dependence of the ferroelectricity and domain switching behavior is thoroughly investigated by PFM. • The Mn first replaces the A-site when the Mn content is small, and replaces the B-site as the Mn content increases. • Enhanced ferroelectricity and piezoelectricity are obtained in the 1mol% Mn-doped PZT thin films. [ABSTRACT FROM AUTHOR]

A novel piezoelectric hydrophone sensor was analyzed, designed and fabricated with PZT-on-Si process platform, which can be used for acquiring or recording underwater sound signals. • A novel passive piezoelectric MEMS vector hydrophone was designed and fabricated based on PZT films. • The hydrophone has excellent low-frequency response and high sensitivity (up to up to -189.3dB in the frequency of 920Hz). • The piezoelectric MEMS vector hydrophone shows good "8" directivity. Hydrophone, serving as a part of sonar, has a significant effect on the performance of acoustic sensors such as frequency characteristics and sensitivity, however, some limitation such as high cost and complexity in SOI manufacturing technique hinder the industrial application of hydrophones. Therefore, a novel Micro-Electro-Mechanical Systems (MEMS) piezoelectric vector hydrophone based on PZT (lead zirconate titanate) film has been adopted in obtaining vector information of underwater sound field. The piezoelectric hydrophone sensor was analyzed, designed and fabricated with PZT-on-Si substrate, and the structure consists of a four-cantilevers and an acoustics columnar cilium fixed on the center micro mass. According to the simulation results, the piezoelectric films are optimally distributed at the tip of the four beams, where the maximum strain locates. Finally, the piezoelectric vector hydrophone was characterized by comparative calibration experiments in a standing wave bucket. This passive MEMS piezoelectric hydrophone has the characteristics of receiving sensitivity with −189.3 dB at 920 Hz (0dB = 1 V/μPa) and a typical directional pattern of "8" shape, low noise output and high dynamic test range, which is suitable for high precision passive underwater detection. [ABSTRACT FROM AUTHOR]

As a promising functional material, ferroelectric Pb(ZrxTi1−x)O3 (PZT) are widely used in many optical and electronic devices. Remarkably, as the film thickness decreases, the materials' properties deviate gradually from those of solid materials. In this work, multilayered PZT thin films with different thicknesses are fabricated by Sol-Gel technique. The thickness effect on its microstructure, ferroelectric, and optical properties has been studied. It is found that the surface quality and the crystalline structure vary with the film thickness. Moreover, the increasing film thickness results in a significant increase in remnant polarization, due to the interfacial layer effect. Meanwhile, the dielectric loss and tunability are strongly dependent on thickness. In terms of optical properties, the refractive index of PZT films increase with the increasing thickness, and the photorefractive effect are also influenced by the thickness, which could all be related to the film density and photovoltaic effect. Besides, the band gap decreases as the film thickness increases. This work is significant for the application of PZT thin film in optical and optoelectronic devices. [ABSTRACT FROM AUTHOR]

Abstract As a functional ferroelectric material, PbZr 0.53 Ti 0.47 O 3 (PZT) film is widely used in many electronic devices. However, with the rapid development of intelligent terminal, traditional PZT device cannot meet the demand for flexible wearable devices. In this work, a high-quality flexible PZT film is fabricated by the controlled spalling technology (CST) for the first time, which is novel, simple and cost-efficient. LaNiO 3 (LNO) film by sol-gel process is used as the buffer layer for the PZT film growth due to good lattice match and low cost. The PZT film on silicon substrate is successfully transferred onto a flexible one by electroplating Ni stressor layer. LNO buffer layer thickness has an important influence on the spalled silicon depth and Ni stressor layer thickness during the spalling process. The exfoliated PZT film based on sandwich capacitor structure Au/PZT/Au with an area of 1 cm2 exhibits good ferroelectric properties under different mechanical deformation. Moreover, the ferroelectric response of flexible PZT film does not show obvious deterioration after repeated operation cycles. Therefore, the flexible PZT thin film has a good application prospect on wearable ferroelectric microelectronics. [ABSTRACT FROM AUTHOR]

Highlights • A stretchable piezoelectric elastic composite is demonstrated in this paper. • The output voltage and current of our composite can reach 8 V and 0.4 μA, respectively. • The proposed composite can be conformally attached on human body for energy harvesting and posture monitoring. Abstract In this work, a stretchable piezoelectric elastic composite has been developed by incorporating PbZr 0.52 Ti 0.48 O 3 (PZT) particles into polymer matrix. The output voltage and current can reach 8 V and 0.4 μA, respectively. Likewise, the steady piezoelectric signal can respond to different strain rates. The measurement on human body shows that the piezoelectric composite can be used to capture kinetic energy and monitor limb motion for body sensor network application. This work is significant for the conformal assembly of piezoelectric devices used in artificial intelligence system. [ABSTRACT FROM AUTHOR]

Because of high temperature process, it has been a challenge to fabricate flexible piezoelectric or ferroelectric devices based on PbZr 0.53 Ti 0.47 O 3 (PZT). In this work, a high-quality flexible PZT film is successfully fabricated by the controlled spalling technology (CST). The PZT film deposited on sapphire substrate using sol-gel method is transferred onto a flexible polyimide (PI) substrate through electroplating Ni stressor layer, realizing the flexible heterogeneous integration of PZT film and PI substrate. The obtained PZT film exhibits a good crystalline perovskite structure and a smooth surface before and after spalling process. The ferroelectric response of the spalled PZT film based on Au/PZT/Au structure does not show obvious deterioration under different mechanical deformation, which indicates good ferroelectric property and stable mechanical performance. Further, the film on flexible Ni layer has the better piezoelectric property compared with that on conventional rigid Pt/Ti/SiO 2 /Si substrate. This work has the important significance for the development of flexible ferroelectric and piezoelectric devices like sensors, memorizers and nanogenerators. • High-quality PZT film on sapphire is successfully transferred onto flexible PI by CST. • Ferroelectric performance of spalled PZT film does not deteriorate after deformation. • The spalled PZT film on flexible Ni layer has a better piezoelectric property. [ABSTRACT FROM AUTHOR]