Ceramic Actuators Research Articles

Preload characteristics identification of the piezoelectric-actuated 1-DOF compliant nanopositioning platform

Packaged piezoelectric ceramic actuators (PPCAs) and compliant mechanisms are attractive for nanopositioning and nanomanipulation due to their ultra-high precision. The way to create and keep a proper and steady connection between both ends of the PPCA and the compliant mechanism is an essential step to achieve such a high accuracy. The connection status affects the initial position of the terminal moving plate, the positioning accuracy and the dynamic performance of the nanopositioning platform, especially during a long-time or high-frequency positioning procedure. This paper presents a novel external preload mechanism and tests it in a 1-degree of freedom (1-DOF) compliant nanopositioning platform. The 1-DOF platform utilizes a parallelogram guiding mechanism and a parallelogram load mechanism to provide a more accurate actual input displacement and output displacement. The simulation results verify the proposed stiffness model and dynamic model of the platform. The values of the preload displacement, actual input displacement and output displacement can be measured by three capacitive sensors during the whole positioning procedure. The test results show the preload characteristics vary with different types or control modes of the PPCA. Some fitting formulas are derived to describe the preload displacement, actual input displacement and output displacement using the nominal elongation signal of the PPCA. With the identification of the preload characteristics, the actual and comprehensive output characteristics of the PPCA can be obtained by the strain gauge sensor (SGS) embedded in the PPCA.

Model Identification and Controller Design for Piezoelectric Ceramic Actuator

Piezoelectric ceramics are widely used in precision measurement and precision positioning, but its nonlinear characteristics seriously affected its application. Thus, firstly input voltage and output displacement data of piezoelectric ceramics are collected by the experiment, the nonlinear characteristics of piezoelectric ceramics is analyzed. Then a piezoelectric ceramic linear model is established using recursive least squares algorithm based on input and output signal. The identification results show that the algorithm is effective. Finally PID controller is designed and the controller has better control effect.

Feedforward nonlinear PID control of a novel micromanipulator using Preisach hysteresis compensator

Recently, flexure-based micromanipulators with a large workspace, high motion precision, and high positioning bandwidth are really attractive for performing practical micro/nano manipulation tasks. Thus, a piezo-actuated flexible two-degrees-of-freedom (2-DOF) micromanipulator integrated with a pair of modified differential lever displacement amplifiers (MDLDA) is developed. To enhance the practical positioning performance of the micromanipulator, a novel feedforward nonlinear Proportion-Integration-Differentiation (FNPID) control strategy combining a nonlinear PID controller with an inverted hysteresis compensator is first proposed and implemented in detail. With the consideration of hysteresis effect inherent in piezoelectric ceramics (PZT) actuators, the hysteresis nonlinearity modeling is conducted by using the Preisach theory. Finally, a series of precision motion trajectory tracking experiments are successfully conducted by using the proposed closed-loop control strategy. The experimental results indicate that the mechanism has achieved a satisfactory performance for performing robotic biomanipulations. HighlightsA novel FNPID controller for the improvement of the practical working frequency of the flexure-based nanopositioning system is proposed.A new concept named area efficiency is proposed to make a quantitative evaluation for the designed nanomanipulator.Preisach method is adopted to model and compensate the complicated hysteresis nonlinearity.A series of trajectory tracking experiments are conducted to make comparisons between the proposed FNPID and PID controller.

Multi-mode Control in a Two-stage Piezoelectric Transducer for an Application of Physical Therapy

A novel as well as unique piezoelectric-driven system constructed with two sets of ceramic actuators connected in a series is able to produce both mechanical vibration and electric power at the output end. With power input to the first ceramic actuator to oscillate, the connected second one makes use of the transmitted mechanical vibration energy to generate electricity via piezoelectric direct effect. An application example of physical therapy including ultrasonic diathermy and electrotherapy is selected for further investigation in this article. Different from the traditional ultrasonic diathermy and electrotherapy systems that are built with their own specific method and independent structure, the developed two-stage piezoelectric transducer can achieve the same application purpose alone. Multi-mode control scheme is proposed by using Frequency- Hopping method to oscillate the first ceramic actuator with different vibration amplitude at various resonance frequencies under schematic switching process. Hence, the second ceramic actuator receives the transmitted energy and generates equivalent electricity with modulation amplitude signal for electrotherapy. The residual energy in the first ceramic actuator is also collected at the output end for ultrasonic diathermy. From the satisfactory experimental outcome, it indicates such a two-stage system not only can generate vibration and electricity but produce composite effect for desired application purpose under well-defined input control signal.

마이크로파 소결법을 이용한 Bi0.5Na0.5TiO3계 적층형 세라믹 액추에이터 제조

A comparative study has been attempted for microwave and conventional sintering of lead-free <TEX>$Bi_{0.5}Na_{0.5}TiO_3(BNT)$</TEX>-based multilayer ceramic actuators(MLAs). It was found that microwave sintering (MWS) could be successfully applied to the co-firing of piezoceramic/AgPd MLAs with a 10 times shorter firing cycle as well as <TEX>$100^{\circ}C$</TEX> lower firing temperature (<TEX>$850^{\circ}C$</TEX>) for sufficient densification than conventional furnace sintering (<TEX>$950^{\circ}C$</TEX>). Furthermore, MWS-derived specimens showed better electric field-induced strain than that of CFS-derived specimens by effectively suppressing interdiffusions between ceramic and electrode layers.

Low temperature sintering and piezoelectric properties of 0.6Pb(Zr1-xTix)O3-0.4Pb(Zn1/6Ni1/6Nb1/3)O3 ceramics

The structural change of 0.6Pb(Zr1-xTix)O3-0.4Pb(Zn1/6Ni1/6Nb2/3)O3 (PZTx–PZNN) from rhombohedral to tetragonal is significantly dependent on the ratio of Ti/Zr. PZT0.570–PZNN ceramics exhibit the highest piezoelectric properties (d33 = 661 pC/N, kp = 0.68, and e33T/e0 = 3928) as a result of the MPB formation. However, the optimum sintering temperature of this composition is approximately 1200 °C, which restricts the use of pure, cheap metal electrodes in the fabrication of multilayer ceramic actuators. In this study, a low temperature sintering of PZT0.570–PZNN ceramics with the addition of CuO is reported. It is found that the addition of CuO can significantly reduce the sintering temperature to 900 °C. The piezoelectric properties of the 2 mol% CuO-added PZT0.570–PZNN sintered at 900 °C are d33 = 602 pC/N, kp = 0.65, e33T/e0 = 3570, and TC = 251 °C.

Active modal damping control of a smart truss structure using a self-organizing fuzzy controller

This paper presents design, implementation and experimental results of active vibration control of a truss structure using a pair of piezoelectric ceramic stack actuators. To reduce the vibrations caused by an impulse force, two active strut members are installed along a vertical of the base bay of the truss. The active strut element consists of a piezoelectric ceramic actuator stack, a force transducer and mechanical interfaces. A self-organizing fuzzy controller (SOFC) is designed to suppress vibration of the truss. The SOFC, which uses the input and output history in its fuzzy rules, is designed to maximize modal damping of a constructed truss structure. Experimental results illustrate that the active piezoceramic strut actuators and the SOFC can effectively reduce vibration of the truss.

Investigation and performance evaluation of a d14 ceramic actuator

Abstract A new wedge-type of ceramic actuator using d14 is developed. Ceramic d14 is rarely seen and addressed in research articles. Compared to the shear formation of the ceramic actuator d15 , the proposed d14 actuator has an advantage of its nearly square and thinner dimensions. Driven by sinusoidal signal, asymmetric Lissajous motion trajectory is gained. Associated with appropriate mechanism, effective transverse displacement is obtained to propel a linear motion stage for instance. Analytical simulation in ANSYS and experiment are carried out to investigate the resonance frequency and vibration mode shape as well as amplitude. Results of both approaches are in close approximation. The feature of the d14 ceramic actuator designed in this study is able to provide large force and medium speed.

Load Characteristics of Lead‐Free Ceramic Multilayer Actuators Based on Bismuth–Sodium–Titanate

The electromechanical behavior of a lead‐free ceramic multilayer actuator is described. The actuator is made of an Nd‐doped [Bi0.500Na0.335K0.125Li0.040]TiO3 ceramic with inner electrodes of an Ag/Pd‐alloy. For electromechanical characterization, the actuator is under constant mechanical stress, and the strain over the applied electric field is recorded. The mechanical stress ranges from 0.1 to 80 MPa. The maximum applied electric field is 8 kV/mm. Starting with 0.1 MPa mechanical stress, the actuator exhibits a maximum strain of &lt;0.1%. With increasing stress, the strain increases up to 0.17% at 5 MPa. With higher stress, the strain decreases and reaches 0.125% at 80 MPa. Reducing the mechanical stress leads to a steady increase in strain, which results in a doubling of the strain at 0.1 MPa compared with the initial value. The strain characteristic contains an electrostrictive part, a linear piezoelectric regime, and some creep behavior.

Drop-on-Demand Inkjet Printhead Performance Enhancement by Dynamic Lumped Element Modeling for Printable Electronics Fabrication

The major challenge in printable electronics fabrication is the print resolution and accuracy. In this paper, the dynamic lumped element model (DLEM) is proposed to directly simulate an inkjet-printed nanosilver droplet formation process and used for predictively controlling jetting characteristics. The static lumped element model (LEM) previously developed by the authors is extended to dynamic model with time-varying equivalent circuits to characterize nonlinear behaviors of piezoelectric printhead. The model is then used to investigate how performance of the piezoelectric ceramic actuator influences jetting characteristics of nanosilver ink. Finally, the proposed DLEM is applied to predict the printing quality using nanosilver ink. Experimental results show that, compared to other analytic models, the proposed DLEM has a simpler structure with the sufficient simulation and prediction accuracy.

Active Elastic Support/Dry Friction Damper with Piezoelectric Ceramic Actuator

The basic operation principle of elastic support/dry friction damper in rotor system was introduced and the unbalance response of the rotor with elastic support/dry friction damper was analyzed theoretically. Based on the previous structure using an electromagnet as actuator, an active elastic support/dry friction damper using piezoelectric ceramic actuator was designed and its effectiveness of reducing rotor vibration when rotor traverses its critical speed and blade-out event happened was experimentally verified. The experimental results show that the active elastic support/dry friction damper with piezoelectric ceramic actuator can significantly reduce vibration in rotor system; the vibration amplitude of the rotor in critical speed region decreased more than 2 times, and the active damper can protect the rotor when a blade-out event happened, so the rotor can traverse the critical speed and shut down smoothly. In addition, the structure is much simpler than the previous, the weight was reduced by half and the power consumption was only 5 W.

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.

Fuzzy PID Control and Simulation of Piezoelectric Ceramic Nanomanipulation System

With widely application of nanomanipulation, the design requirements of nanomanipulation control system is higher and higher. To improve the control precision of nano-components, it is important to do research on closed-loop control method for nanomanipulation. The piezoelectric ceramic actuator has the inherent characteristic of hysteresis, creep and nonlinear. Attocube is adopted as piezoelectric ceramic actuator in this system. Aiming at the designed nanomanipulation system based on Attocube, the closed-loop nanomanipulation control method based on fuzzy PID is studied. Based on the simplified modeling of piezoelectric devices and its displacement model, the controller of nanomanipulation system is designed and its simulation based on Matlab is conducted. Simulational results prove the effectiveness of the method.

Electromechanical Characterization of Bi-based Lead Free Ceramic Multilayer Actuators

The electromechanical behaviour of a lead-free ceramic multilayer actuator is described. The actuator is made of a Nd-doped bismuth-alkali-titanate ceramic with inner electrodes of an Ag/Pd-alloy. For electromechanical characterization the actuator is under constant mechanical load and the strain over the applied electric field is recorded. The mechanical load ranges from 0.1 to 80 MPa. The maximum applied electric field is 8 kV/mm. Starting with 0.1 MPa mechanical load the actuator exhibits a maximum strain of less than 0.1%. With increasing load the strain increases up to 0.17 % at 5 MPa. With higher load the strain decreases and reaches 0.125% at 80 MPa. Reducing the mechanical load leads to a steady increase in strain, which results in a doubling of the strain at 0.1 MPa compared to the initial value. The strain characteristic contains an electrostrictive part, a linear piezoelectric regime as well as some creep behaviour.

The Application of a Grating Tiling Device with Parallel Mechanism in an Inertial Confinement Fusion (ICF) System

The size of pulse compression gratings (PCG) is very big in the ICF system, so we obtained a large size grating by mechanically stitching small caliber gratings. And we design the splicing mechanism to be a 5-DOF Parallel Mechanism with macro/micro dual feed drive control to meet the requirements of large travel, high precision, high stability and 5-DOF of the grating tiling. The macro-moving part is designed to be the 5PTS-1PPS parallel mechanism, using the Feed Mechanism of ballscrew with Stepper Motor Drive.The micro-moving part is designed to be 5TSP-1PPS parallel mechanism, using the feed mechanism of Flexure Hinge with Piezoelectric Ceramic Actuator. We derived control algorithm of parallel mechanism by the method of the Kinematics of parallel mechanism. We analyzed the systematic error and put forward the error correction method in order to improve the positioning accuracy. At last, we designed an optical detecting system to evaluate the feasibility of this scheme, the positioning accuracy and the Stability of parallel Splicing structure. The results showed that the mechanism performance can meet the requirements of grating tiling work.

Research of Active Noise Control For Transformer Based on Piezoelectric Ceramic Actuator

A common source of noise is operational excitations of mechanical devices, which cause vibrations and thus sound radiation from their surfaces. Plate and shell structures in transformer, vehicle or airplane applications vibrating in resonance show particularly high noise levels. Classic methods of noise reduction such as passive damping or anti-noise are not efficient enough in certain cases. Therefore, the use of structural control for reduction of sound radiation is presented in this paper. A piezoelectric ceramic actuator (PCA) for the active noise control is also proposed. The structure of the proposed PCA is discussed and the control method of the structure is carried out. The proposed PCA has excellent performance compared with conventional ones, such as more force, convenient installation and disassembly. The active noise control (ANC) system and control algorithm are also discussed in this paper. The performance of the proposed controller is analyzed through simulation in the Matlab/Simulink.

Fabrication and Electrical Properties of Multilayer Ceramic Actuator Using Lead-Free (Bi1/2K1/2)TiO3

A prototype of a multilayer actuator (MLA) was fabricated using (Bi1/2K1/2)TiO3 (BKT) ceramics as active layers and Ag–Pd (7:3) as inner electrodes. Then, their microstructures and electrical properties were investigated. From the scanning electron microscope (SEM) observation, the thickness of the BKT active layers between electrodes was estimated to be approximately 60 µm for the body co-fired at 1045 °C for 10 h. Also, SEM images showed homogeneous and dense microstructures on the BKT active layers. Additionally, the interface between BKT and the Ag–Pd electrode was clearly distinguished and there are no significant signs of reaction or diffusion between them at least from the SEM micrographs. The resistivity ρ of BKT sample co-fired at 1045 °C for 10 h was about 1011 Ω·cm on average, which is sufficient for applying a high DC electric field to the sample. From the measurement of the field-induce strain S under unipolar driving at 100 kV/cm, a large strain of 0.14% at 100 kV/cm was obtained and the longitudinal dynamic displacement was 1 µm at the same electric field. The normalized d33* was calculated to be 138 pm/V, which is similar to that in the bulk samples. This result indicates that the BKT-based multilayered prototype efficiently functioned under unipolar driving up to 100 kV/cm.

Parametric Identification of Bouc-Wen Hysteresis Model for Piezoelectric Ceramic Actuator Based on Immune Particle Swarm Optimization Algorithm

This paper is concerned with the parametric identification based on immune particle swarm optimization (IPSO) algorithm for Bouc-Wen model of piezoelectric ceramic actuators (PCA). IPSO algorithm is an algorithm that introduces the immunological memory and selection mechanism of concentration of antibody of immune system to PSO algorithm. It is used to identify unknown parameters of Bouc-Wen model, one of the most widely used parametric models of hysteresis in mechanics. The experimental results reveal that IPSO algorithm has better precision and convergence.

Piezoelectric control of delamination response in woven fabric composites under mode I loading

This paper investigates the application of piezoelectric actuators to control the delamination response in woven fabric composites subjected to Mode I loading. Experiments were conducted on a double cantilever beam (DCB) specimen of woven glass fiber reinforced polymer (GFRP) composite laminates with piezoelectric ceramic actuators bonded on the surfaces, in order to evaluate the dependence of the delamination behavior on the applied electric fields. A finite element analysis of the DCB specimen with surface-bonded actuators was also performed, and a comparison was made between the finite element predictions and the test results. In addition, the effect of the actuator location on the effectiveness of the piezoelectric control was examined numerically.

Production of BaTiO&lt;sub&gt;2&lt;/sub&gt; Nanocrystalline Powders by High Energy Milling and Piezoelectric Properties of Corresponding Ceramics

Barium titanate (BaTiO3 or BT) has become one of the most studied functional materials due to its potential application as multilayer ceramic capacitors, PTC thermistors, electromechanical devices, piezoelectric transducers, actuators, dynamic RAM or logic circuitry as well as a great variety of electro-optical devices. In the present study, high energy ball milling has been used to produce nanocrystalline powders of BT. Two categories of powders having average particle size of 35 nm and 25 nm were prepared by setting the milling speed at 250 rpm and 300 rpm respectively, fixing the milling time at 30 hours. Four ceramic samples, BT35-1350, BT25-1350, BT35-1400 and BT25-1400, were formed by sintering the two types of powders at 1350oC and 1400oC for 3 hours. The ferroelectric and piezoelectric properties of the ceramic samples were studied and found to be dependent on the size of the starting nanopowders. The bulk density and piezoelectric constant (d33) of B25-1350 were found to be less than those of BT35-1350, while the reverse was true in case of BT25-1400 and BT35-1400. Well saturated P-E hysteresis loops were observed for all the ceramics with the size and shape of the loops appearing different for the four samples. For both the pairs of ceramics sintered at 1350oC and 1400oC, the remnant polarization (Pr) decreases with starting particle size, that is, as we go from BT35-1350 to BT25-1350 as well as from BT35-1400 to BT25-1400. However, with decreasing particle size of the starting powders, the coercive field (Ec) increases for the ceramics sintered at 1350oC and decreases for the ceramics sintered at 1400oC. The study reveals the importance of an optimized combination of the size of the starting nanopowders and sintering temperature for obtaining BT ceramics with the desired properties.