Multilayer PZT Research Articles

Carbon footprint of piezoelectrics from multi-layer PZT stacks to piezoelectric energy harvesting systems in roads

Piezoelectric energy harvesting devices (PEHDs) for road installation are being researched as potentially low-emission electrical generators, but their life cycle greenhouse gas (GHG) emissions must be assessed to guide their design and implementation toward minimizing their carbon footprint. Parametric life cycle assessments (LCAs) of a PEHD, its generator, and the piezoelectric material were performed using data from a pilot-scale PEHD installation. The GHG emissions of the lead zirconate titanate (PZT) piezoelectric stack were determined to be lower than previously reported in the literature at 10.81-15.90kg CO2eq/kg piezoelectric. The GHG emissions of electricity generated by a PEHD range from 48.65-588.63g CO2eq/kWh, spanning from similar to renewables to slightly higher than electricity from natural gas. Sensitivity analysis indicated that spatial parameters and the device lifetime had the largest influence on the LCA results. PEHDs installed on roads show potential to be low-GHG emission energy systems.

Improvement of energy storage performance in PbZr0.52Ti0.48O3/PbZrO3 multilayer thin films via regulating PbZrO3 thickness

In this work, to prepare the PbZr0.52Ti0.48O3(PZT)/PbZrO3(PZ) multilayer films, PZ films and PZT films were spin-coated on LaNiO3/SiO2/Si substrates in sequence by the sol-gel method, and the PZ films were prepared using PZ precursor solution with different concentrations. After each spin-coating, PZ layer and PZT layer were annealed with rapid thermal annealing (RTA) technique at 650 °C and 550 °C, respectively. The crystal structures, microstructures and electrical properties of the films with different PZ film thickness were comprehensively investigated. The PZ films with different thickness showed perovskite phase. The PZT films on crystallized PZ films exhibited the coexistence of pyrochlore phase and perovskite phase at the annealing temperature of 550 °C. The PZT/PZ multilayer films with 0.2 M PZ precursor solution exhibit typical anti-ferroelectricity with double hysteresis loops, while other multilayer films exhibit nearly linear loops. In addition, the recoverable energy storage density increases with the increase of the film thickness and reaches the maximum value 32.4 J/cm3 in the PZT/PZ multilayer films with 0.4 M PZ precursor solution. Therefore, the ferroelectric properties of the PZT/PZ multilayer films could be regulated by different PZ film thickness, which effectively further enhances the energy storage performance.

Improved electrical properties of sputtering Pb1.10(Zr0.52,Ti0.48)O3/Pb1.25(Zr0.52,Ti0.48)O3 multilayer thin films

Multilayer PZT thin films composed of Pb1.10(Zr0.52,Ti0.48)O3 and Pb1.25(Zr0.52,Ti0.48)O3 films were deposited on Pt(111)/Ti/SiO2/Si(100) substrate coated by Pb1.10(Zr0.52,Ti0.48)O3 buffer layer using RF magnetron sputtering. The effect of variation of layer numbers of Pb1.10(Zr0.52,Ti0.48)O3 and Pb1.25(Zr0.52,Ti0.48)O3 thin films in multilayer PZT films was investigated. X-ray diffraction (XRD) analysis indicates all PZT films possess pure perovskite phase and (111) preferred orientation. For multilayer thin films, dense perovskite microstructures without obvious defects were observed using scanning electron microscope (SEM). Optimal dielectric properties with a er of 1092 and a tanδ of 0.04 at 1 kHz were obtained in the PZT film with the maximum layer numbers (8-layer film, namely L-8). Well-saturated P–E was observed in L-8 film by a standard ferroelectric test system (Pr = 26.1 µC/cm2, Ec = 60.1 kV/cm). Moreover, a Lower leakage current density (J = 5.49 × 10−6 A/cm2 at 117 kV) was achieved in sample L-8.

MEMS Energy Harvesting Based on Uniform-Stress Cantilever with Multilayer PZT Thin Films

Multilayered piezoelectric MEMS energy harvesters based on sputtering depositions are designed and fabricated. To obtain high endurance and output power, the unimorph cantilever structure with totally 10 μm-thick multilayered PZT thin films and 80 μm-thick Si elastic layer is designed. In addition, the cantilever is designed to undergo a uniform stress on the PZT. The output power and voltage was 90 μW and 1.0 Vrms under the input acceleration of approximately 1.2 G (=11.76 m/s2) and optimum load resistance.

The study of the properties of lead zirconate-titanate films on silicon substrate after halogen lamps rapid thermal annealing

Ferroelectric thin films of lead zirconate titanate (PZT) are important is creation of ferroelectric MEMS, memory devices, sensors of physical quantities and converters energy. The thermal annealing is used to obtain satisfactory electro-physical parameters and optimal crystal structure PZT films. The rapid thermal annealing (RTA) in comparison with isothermal annealing has a possibility of selective annealing of individual layers of the multilayer PZT composition by selecting appropriate temperature and duration of the RTA. The purpose of this work is to study the phase-structural state of PZT films formed by high-frequency reactive plasma sputtering and subjected to rapid thermal annealing by halogen lamps. The PZT thin films with a thickness of 1.0 ± 0.1 µm were deposited by oxygen atmosphere high-frequency reactive plasma sputtering on silicon (100) substrates and silicon substrates with SiO2 on surface. After applying, PZT film underwent RTA at temperatures of 600-800 °C and with speed 60 degrees/s. With X-ray phase analysis, the structure-phase composition of the PZT film is revealed. Besides that, the effect of RTA was investigated using electron microscopy. It is established that temperature change at RTA leads to a qualitative change in the phase-structural state of the PZT films as compared to their initial state. This gives a chance to use RTA in formation of the PZT films with given parameters.

Multilayer PZT 95/5 Antiferroelectric Film Energy Storage Devices with Giant Power Density.

A new type of energy storage devices utilizing multilayer Pb(Zr0.95 Ti0.05 )0.98 Nb0.02 O3 films is studied experimentally and numerically. To release the stored energy, the multilayer ferroelectric structures are subjected to adiabatic compression perpendicular to the polarization direction. Obtained results indicate that electrical interference between layers (10-120 layers) during stress wave transit through the structures has an effect on the generated current waveforms, but no impact on the released electric charge. The multilayer films undergo a pressure-induced phase transition to antiferroelectric phase at 1.7 GPa adiabatic compression and become completely depolarized, releasing surface screening charge with density equal to their remnant polarization. An energy density of 3 J cm-3 is successfully achieved with giant power density on the order of 2 MW cm-3 , which is four orders of magnitude higher than that of any other type of energy storage device. The outputs of multilayer structures can be precisely controlled by the parameters of the ferroelectric layer and the number of layers. Multilayer film modules with a volume of 0.7 cm3 are capable of producing 2.4 kA current, not achievable in electrochemical capacitors or batteries, which will greatly enhance the miniaturization and integration requirements for emerging high-power applications.

Thickness Dependence of Ferroelectric and Optical Properties in Pb(Zr0.53Ti0.47)O3 Thin Films.

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.

Impedance Matching Techniques of Multi-layered PZT Ceramics for Piezoelectric Energy Harvesters

In this research, the possibility of passive damping system based on the piezoelectric energy harvesting has been proposed and tested. To apply passive damper system, piezoelectric ceramics were stacked, and impedance was matched. Piezoelectric energy harvesters were employed due to their excellent piezoelectric and robust properties. Especially, multilayered (Pb,Zr)TiO3 piezoelectric ceramic have high piezoelectric charge coefficient d33 and piezoelectric voltage coefficient g33 for actuator and harvester applications, respectively. Multilayered (Pb,Zr)TiO3 piezoelectric ceramics can generate comparatively high current level compared with single layered piezoelectric ceramics due to its parallel connected capacitors. In energy harvester applications, multilayered (Pb,Zr)TiO3 piezoelectric ceramics have a role of voltage source with capacitive impedance. Due to considerable impedance in voltage sources, the role of impedance matching between the source and output terminal is more critical. By employing the piezoelectric energy harvesting system for the passive damper, output energy of 11 μJ/cm3 was obtained at the 100 μF capacitors. Therefore, impedance matching technologies were intensively investigated to obtain maximum output energy for storing capacitors.

Piezoelectric MEMS with multilayered Pb(Zr,Ti)O3 thin films for energy harvesting

This study aims to report the design of high-performance piezoelectric MEMS energy harvesters using a full batch MEMS-fabrication process with a Si proof mass and multilayered Pb(Zr,Ti)O3 (PZT) thin films without bonding of a proof mass and/or bulk piezoelectric ceramics. These devices contain sputtered multilayered PZT thin films with internal metal electrodes as a thick energy-conversion layer. The thickening of the piezoelectric layer by multilayer sputter deposition technique enabled the batch fabrication of high-performance piezoelectric MEMS harvesters. These fabricated device with the footprint of 10 × 10 mm2 was found to provide a high output power of 53.7 μW per gravitational acceleration. These results are expected to be useful for the future development of alternatives to batteries for autonomous sensor systems.

Direct-Write Laser Greyscale Lithography for Multi-Layer Lead Zirconate Titanate Thin Films.

Direct-write laser greyscale lithography has been used to facilitate a single step patterning technique for multi-layer lead zirconate titanate (PZT) thin films. A 2.55 μm thick photoresist was patterned with a direct-write laser. The intensity of the laser was varied to create both tiered and sloped structures that are subsequently transferred into multi-layer PZT(52/48) stacks using a single Ar ion mill etch. Traditional processing requires a separate photolithography step and an ion mill etch for each layer of the substrate, which can be costly and time consuming. The novel process allows access to buried electrode layers in the multi-layer stack in a single photolithography step. The greyscale process was demonstrated on three 150 mm diameter Si substrates configured with a 0.5 μm thick SiO2 elastic layer, a base electrode of Pt/TiO2, and a stack of four PZT(52/48) thin films of either 0.25 μm thickness per layer or 0.50 μm thickness per layer, and using either Pt or IrO2 electrodes above and below each layer. Stacked capacitor structures were patterned and results will be reported on the ferroelectric and electromechanical properties using various wiring configurations and compared to comparable single layer PZT configurations.

Performance analysis on cascaded asymmetric photonic crystal Mach–Zehnder tunable filter

A cascaded asymmetric photonic crystal Mach–Zehnder filter structure is proposed to improve the quality factor (Q value) and the sensitivity of the tunable optical filter. The mathematical relationship between the output wavelength of M–Z filter and the voltage applied on the multilayer PZT is established. The simulation results show that the full width at half maximum can be decreased from 17 nm to 9 nm, in addition, the transmission peak wavelength varies by adjusting the applied voltage and the sensitivity can attain to 0.7 nm/V by using the multilayer PZT, which can achieve tunable filtering effectively.

Splitting of neutral mechanical plane of conformal, multilayer piezoelectric mechanical energy harvester

Flexible piezoelectric mechanical energy harvesters (MEHs) are of recent interest as an important emerging variant of traditional piezoelectric devices. The design of stacking multilayer MEHs with adhesive in between is an effective way to enhance the magnitude of power generation. Here, we present an analytic model to study the mechanical behavior of the multilayer MEHs based on lead zirconate titanate (PZT) subjected to Euler buckling. Being different from the hypothesis of the plane section for the entire stack, it is found that each polyimide (PI) layer holds plane section of its own, while soft adhesives serve as shear lags. Accordingly, the neutral mechanical plane is split into multiple ones. The deformation is almost the same for each PI layer, as well as PZT arrays, which is very beneficial to avoid the premature failure of devices. The extreme cases and the transition of these cases are all captured quantitatively with a unified analytic model which is verified by the finite element method. A dimensionless parameter is obtained to characterize the degree of the splitting of neutral mechanical plane, which is significant for the design of the multilayer PZT MEHs.

Co-firing of PZT–PMS–PZN/Ag Multilayer Actuator Prepared by Tape-Casting Method

Abstract Multilayer ceramic actuator composed of piezoelectrically active 0.90Pb(Zr0.48Ti0.52)O3–0.05Pb(Mn1/3Sb2/3)O3–0.05Pb(Zn1/3Nb2/3)O3 (PZT–PMS–PZN) layers and electrically conducting silver metal layers were fabricated. Low-temperature sinterable PZT–PMS–PZN ceramics were used as the piezoelectric layers, and silver paste was used as the conductive inner-electrode layers. PZT–PMS–PZN powder, adding 1% CuO as a sintering agent, was prepared by a conventional solid-state reaction process. The green sheet was fabricated by tape-casting method. Silver inner-electrode was printed on the green-tape sheets and the sheets were stacked, warm-pressed, and sintered at 900°C for 4 h after burning out the organic additions. The sintered multilayer ceramics actuator shows distinct layers with few defects in the interfaces. The thicknesses of the piezoelectric and conducting layers are about 40 and 6 μm, respectively. The multilayer PZT–PMS–PZN actuator, composed of 60 active piezoelectric layers, presents a longitudinal displacement of about 2.7 μm at an applied voltage of 80 V, approximately 0.1% of the total thickness of itself.

Multi-layered piezoelectric energy harvesters based on PZT ceramic actuators

In this study, we have investigated 1–3 story structured piezoelectric energy harvesters based on lead zirconate titanate (PZT) multi-layered actuators. These piezoelectric energy harvesters were fabricated using Pb(Zr,Ti)O3 based ceramic actuators. The multi-layered PZT actuators were based on green sheets that were prepared by a tape casting process. The ceramic actuators were attached on metallic electrodes with poled states. The structures were filled with polydimethylsiloxane (PDMS). The multi-layered piezoelectric energy harvesters were stacked as single-story structured, double-story structured, and triple-story structured devices, respectively. Generated output voltages, stored power, and maximum output power with various loads of the piezoelectric energy harvesters with various story structures were analyzed.

Reliability of Ferroelectric Multilayer PZT Thick Films Fabricated by Aerosol Deposition

Multilayer PZT thick film (∼10 μm) on Ti-metal substrate fabricated by aerosol deposition (AD) with LaNiO3 (LNO) top and bottom electrode and investigated their dielectric and ferroelectric properties. The film was found to be highly dense and crack free. The ferroelectric fatigue up to 109 bipolar switching cycles as well as the thermal shock (−30°C and 90°C) with 30 cycles test revealed no significant change in the remnant polarization, dielectric constant and dielectric loss was observed which shows the reliability of AD film. The temperature dependent dielectric and ferroelectric properties of PZT thick films were discussed in this paper.

단결정 PMN-29PT 적층형 작동기: 제작과 성능

Piezoelectric PMN-29PT single crystal multilayer actuators [100 ㎟ in cross section and 22 mm in length] are designed and fabricated by stacking square plates [10 × 10 × 0.5(t) ㎣] of PMN-29PT single crystals having a d 33 of about 1,500 pC/N. The characteristics of PMN-29PT multilayer actuators are compared with those of P-025.40P multilayer PZT ceramic actuators [490 ㎟ in cross section and 60 mm in length] produced by PI in Germany. Even though the total volume of the PMN-29PT single crystal multilayer actuator is only about 7.5% of that of the P-025.40P ceramic multilayer actuator, PMN-29PT single crystal multilayer actuators are expected to show very similar properties to P-025.40P ceramic actuators in terms of static stroke and blocking force. Therefore, on the basis of their smaller mass and volume compared to the conventional PZT ceramic multilayer actuators, piezoelectric PMN-29PT single crystal multilayer actuators have significant potential regarding the development of various high performance actuators for aerospace subsystems.

Fabrication of a piezoelectric microcantilever array with a large initial deflection and an application to electrical energy harvesting

This paper presents a new method to fabricate a multi-layered PZT microcantilever with a large upward initial deflection and the application for energy harvesting. The upward initial deflection is obtained by asymmetrically distributed residual stresses in the thin multilayer. The numerical analysis is carried out to simulate the upward deflection only based on the temperature history of process. In particular, the proposed method using the metal etching of the adhesion layer of tantalum and the plasma ashing of parylene-C is compared with that using the dry etching of polycrystalline silicon as a sacrificial layer to release the microcantilever from the substrate in fabrication simplicity and process time. An experimental evaluation confirmed that the proposed fabrication method is very simple and effective. The feasibility of the electricity generation is also measured on the PZT vibration test bed. A nano-watt electrical output is obtained, much higher than noise level. Also, a large output is obtained at a large length of the microcantilever with a large initial deflection.

Fabrication of Simple and Ring-Type Piezo Actuators and Their Characterization

A piezo multilayered stack of height 10 mm is fabricated using 80 μm thick PZT tapes prepared by tape-casting technique. About 120 layers of thin tapes are dried, screen-printed with Pt-electrode paste, stacked, laminated, and then isopressed to obtain a green multilayered stack. Cofiring of the stack is carried out at C for 1 h with very slow heating rate ( per 1 h). The sintered stack is poled at 2 kV per mm in hot (C) silicone oil bath for 45 minutes, and free displacement and block force were characterized. The actuator generates free displacement of 10 μm (0.1% strain) and block force of 1427 N at 175 V. In a similar way, a ring-shaped multilayered PZT stack was fabricated; the displacement was measured to be 8 μm. The ring-type actuator is mainly used for fluid flow control in space vehicles.

Design, Modeling and Analysis of Implementing a Multilayer Piezoelectric Vibration Energy Harvesting Mechanism in the Vehicle Suspension

This paper deals with the design, modeling and analysis of implementing a Multilayer Piezoelectric Vibration Energy Harvesting (ML PZT VEH) Mechanism in the vehicle suspension. The principle of work of the proposed ML PZT VEH mechanism is reducing the relative motion of the suspension, amplifying the applied force to the PZT by a specific design of mechanism and combining a single layer PZT into multilayer PZT to increase the produced electricity. To maintain the performance of suspension as the original suspension, the ML PZT VEH mechanism is mounted in series with the spring of the suspension. The proposed ML PZT VEH mechanism and its implementation to the vehicle suspension were mathematically modeled. Responses of the vehicle before and after implementing ML PZT VEH mechanism were simulated. The results show the proposed mechanism can produce output voltage of 2.75 and power of 7.17 times bigger than direct mounting to the vehicle suspension. And the simulation result shows that mounting ML PZT VEH mechanism in series with the spring of the vehicle suspension does not change the performance of suspension.

Particle Sorting Using a PZT Jet Pump

A method of using a PZT jet pump to separate small objects from the flow of the mainstream is presented. The objects may be, for example, cells, medical markers, or hard-to-handle machine parts. For such particles, sorting methods that change the channel mechanically are not particle-friendly and tend to damage them. This research is related to the development of equipment that uses a jet stream from an injection pump driven by a PZT actuator to sort small particles. The particles are separated from the mainstream by small amounts of fluid the pump injects. The injection is produced by the impulsive force generated when voltage is rapidly applied to a multilayer PZT element. In the experiment, white or black polystyrene particles 1 mm in diameter are sorted by color, their colors discriminated by a reflection-type photo sensor. By timing the pump according to the velocity of the flow, a high separation success rate is achieved.