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To improve the performance of piezoelectric actuators, new 3-D designs were developed to gain higher displacements or specific bending effects. Such 3-D actuators of e.g. helical structure have next to the standard actuator or sensor applications the potential to be used in Hi-Fi digital sound projectors. To lower the voltage of the power supply fo...
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PZT ML stacks and Amplified Piezo Actuators (APAs) were fabricated by tape casting
technique using in house prepared PZT powder. ML stacks of height ~10 mm containing about
120-150 layers each of 80-100 μm thick were used for fabrication of actuators. PZT tapes were
prepared by tape casting well dispersed PZT slurry with optimum amount of solvent,...
Citations
... A variety of piezoelectric actuators using bulk, multilayer, and film piezoelectric materials are available, in which the most common commercialized material and structure for the piezoelectric actuator applications is the lead zirconate titanate (Pb(Zr x Ti 1−x )O 3 , PZT)-based ceramic multilayers. Compared with the traditional ERMs and LRAs, piezoelectric actuators are more accurate with faster responses, higher acceleration rates, and forces and have more convenience for miniaturization, and most importantly, the unique ability to achieve highdefinition tactile sensation [74][75][76][77][78]. Piezoelectric actuators are considered to be the most suitable for haptic feedback applications, whose specific materials and research studies will be discussed in the next section. ...
Haptic technology that provides tactile sensation feedback by utilizing actuators to achieve the purpose of human–computer interaction is obtaining increasing applications in electronic devices. This review covers four kinds of electromechanical actuators useful for achieving haptic feedback: electromagnetic, electrostatic, piezoelectric, and electrostrictive actuators. The driving principles, working conditions, applicable scopes, and characteristics of the different actuators are fully compared. The designs and values of piezoelectric actuators to achieve sophisticated and high-definition haptic effect sensations are particularly highlighted. The current status and directions for future development of the different types of haptic actuators are discussed.
... Meanwhile, vibrotactile actuators have become one of the critical electronic parts of mobile consumer electronic devices, because most of the devices have replaced mechanical buttons with a touch panel. Although conventional vibrotactile actuators are widely used for providing tactile feedback to the user, they are usually rigid [6][7][8][9]. Therefore, it is not easy to apply these actuators to flexible mobile consumer electronic devices. ...
The most important thing in a thin and soft haptic module with an electroactive polymer actuator array is to increase its vibrotactile amplitude and to create a variety of vibrotactile sensations. In this paper, we introduce a thin film-type electroactive polymer actuator array capable of stimulating two types of human mechanoreceptors simultaneously, and we present a haptic rendering method that maximizes the actuators’ vibrational force without improving the array’s haptic performance. The increase in vibrational amplitude of the soft electroactive polymer actuator array is achieved by creating a beat vibration, which is an interference pattern of two vibrations with slightly different frequencies. The textures of a target object are translated into haptic stimuli using the proposed method. We conducted qualitative and quantitative experiments to evaluate the performance of the proposed rendering method. The results showed that this method not only amplifies the vibration’s amplitude but also haptically simulates various objects’ surfaces.
... Free-standing thick films also have lower coercive fields because there is no conditions of domain nucleation at the surfaces of thick films, which is different from thick films with substrate [14]. Tape-casting is an efficient method to prepare thick films which is widely used for experiment and production [15]. And the tape-casted thick films are not necessary to be attached to the substrate compared with screen-printing method, so ceramic slurries was prepared by tape-casting method in this paper. ...
High performance free-standing multilayer PNN–PZN–PZT thick films have been successfully fabricated by tape-casting and one step co-fired method. Optimal formulation of slurries has been found. Free-standing multilayer thick films with Ag electrodes were obtained after co-fired at 900 °C. With proper pretreatment, compact structure and well combined PZT layers can be obtained, which indicates the tightly integrated structure of multilayer thick films. Diffusion and permeation between Ag electrodes and PZT layers was not observed in specimens sintered at 900 °C. The influences of organic content and sintering temperature on density and crystallinity were discussed. Nine layered specimens showed great electrical properties: d33, tanδ, ε33T /ε0, g33 and Pr of 1880 pC N⁻¹, 2.3%, 1067, 199.00 mV m/N, 82.77 µC cm⁻². The displacement of nine layers specimens under same applied voltage was increased from 901 to 8489 nm compared with bulk ceramics. Those outstanding properties indicate that co-fired free-standing PNN–PZN–PZT multilayer thick films are suitable for application in MEMS system, energy harvesting device and piezoelectric power generation.
... In order to create a variety of tactile sensation, it is necessary to use vibro-tactile actuators that can vibrate in a wide frequency range. Many vibro-tactile actuators have been researched or on-going, and some of them have been already commercialized, including eccentric motor, linear resonant actuator, piezoelectric actuator and cellulose acetate film actuator [6][7][8][9][10][11][12][13][14][15][16]. ...
This study deals with ultrasonic wave propagation on a piezoelectric polymer substrate for tactile actuator. On the piezoelectric polymer substrate, a pair of interdigital transductor (IDT) electrodes is patterned by lift-off process and a resonator is made by exciting the IDTs. A standing wave is generated between the pair of IDT electrodes, of which the wavelength matches with the distance between two IDTs. The standing ultrasonic waves can give different textures to the users. The wave propagation in this periodic structure on the polymer substrate is studied by harmonic and transient analysis. Vertical displacement and induced voltage at the output IDT electrode are calculated and the ultrasonic wave generation is experimentally verified. The proposed concept of tactile actuator based on ultrasonic wave is explained.
... In order to create a variety of tactile sensation, it is necessary to use vibro-tactile actuators that can vibrate in a wide frequency range. Many vibro-tactile actuators have been researched or on-going, and some of them have been already commercialized, including eccentric motor, linear resonant actuator, piezoelectric actuator and cellulose acetate film actuator [6][7][8][9][10][11][12][13][14][15][16]. ...
This study deals with ultrasonic wave propagation on a piezoelectric polymer substrate for tactile actuator. On the piezoelectric polymer substrate, a pair of interdigital transductor (IDT) electrodes is patterned by lift-off process and a resonator is made by exciting the IDTs. A
standing wave is generated between the pair of IDT electrodes, of which the wavelength matches with the distance between two IDTs. The standing ultrasonic waves can give different textures to the users. The wave propagation in this periodic structure on the polymer substrate is studied by harmonic and transient analysis. Vertical displacement and induced voltage at the output IDT electrode are calculated and the ultrasonic wave generation is experimentally verified. The proposed concept of tactile actuator based on ultrasonic wave is explained.
... Regarding the manufacture of rotationally symmetric structures, the principle of spiral winding of ceramic green tapes was adapted from the paper industry. Winding of ceramic green tapes is a less common technique; it was used to generate SiC multilayer tubes (Badini et al., 2002;Pavese et al., 2008), Ceramic Matrix Composite (CMC) components (Shi et al., 2014) or helixshaped piezo actuators (Wagner et al., 2005). Wound structures can either exhibit weak (Jakobsen et al., 2014) or strong interfaces . ...
Rotationally symmetric refractory nozzles have been fabricated using the spiral winding technique with ceramic alumina green tapes. Different layer designs have been developed in order to obtain a homogeneous fired structure with locally delaminated interfaces, which are expected to improve the thermal shock behavior. In this regard, the microstructure of all fired structures has been investigated. Thermal shock tests have been conducted to evaluate the impact of the layer design on the formation of micro cracks and other damage. Subsequently, the corrosion behavior of these nozzle compositions has been investigated.
... When the PZT element is contacted to the skin of the chest, the required driving voltage to generate sufficient displacement of common piezoelectric actuator has been around 30 V or more in previous studies [8][9][10][11][12]. It is therefore difficult to ensure safety when the PZT element directly contacts the skin. ...
Recently, given Japan's aging society background, wearable healthcare devices have increasingly attracted attention. Many devices have been developed, but most devices have only a sensing function. To expand the application area of wearable healthcare devices, an interactive communication function with the human body is required using an actuator. For example, a device must be useful for medication assistance, predictive alerts of a disease such as arrhythmia, and exercise. In this work, a haptic stimulus actuator using a piezoelectric pump is proposed to realize a large displacement in wearable devices. The proposed actuator drives tactile sensation of the human body. The measurement results obtained using a sensory examination demonstrate that the proposed actuator can generate sufficient stimuli even if adhered to the chest, which has fewer tactile receptors than either the fingertip or wrist.
... This technique is often used in the paper industry to fabricate devices, like paper rolls 12 -14 . Reports about winding ceramic green tapes are rare, but there have been attempts to fabricate some structures, such as piezoelectric multilayer actuators in the shape of a double helix structure 15 . Spiral winding of ceramic green tapes was conducted by Scheithauer et al. using zirconia and calcium aluminate tapes to manufacture tubes for energy, environmental, and high-temperature applications 16 . ...
... In order to be able to mount the tube in a testing device, a fixture consisting of A1-tape strips with a green thickness of 600 lm was additionally wound on one end of the nozzle using the parallel winding technique. A sintered nozzle with a fixture is shown in Fig. 2. The strain e which occurs at the outside of the tape can be calculated for each wound layer according to Equation 1, with the thickness d of the wound layer and the radius r 0 , which is the sum of the radius of the mandrel and the thickness of all already wound layers underneath 15 . ...
In order to create rotationally symmetric refractory devices from ceramic green tapes, the spiral winding method, whichis mainly known from the paper industry, was applied. Different green tapes with varying properties with regard to shrinkage, porosity and Young's modulus were used to generate multilayer tubes with the spiral winding and the cold low pressure lamination technique. The tubes were fired in air and their microstructure was investigated. Thermal shock tests were conducted to evaluate the applicability of the fabricated structures for refractory applications. The correlation between the microstructure and thermal shock behaviour of the tubes is discussed
... The obvious advantage of the d 15 actuator design is that the piezoelectric shear strain is transformed directly into the angular displacement, whereas in the previously reported actuators, the conversion mechanism into the torsional motion was rather complicated, which thus required a sophisticated design of the whole system. The second is the helical/spiral piezoelectric element, which has been studied by several institutes (Chen et al., 2008;Lee et al., 2010;Mohammadi et al., 1999;Pearce et al., 2002;Wagner et al., 2005). These works include unimorph and bimorph actuators (Pearce et al., 2002) and the spiral bender (Lee et al., 2010;Mohammadi et al., 1999;Wagner et al., 2005). ...
... The second is the helical/spiral piezoelectric element, which has been studied by several institutes (Chen et al., 2008;Lee et al., 2010;Mohammadi et al., 1999;Pearce et al., 2002;Wagner et al., 2005). These works include unimorph and bimorph actuators (Pearce et al., 2002) and the spiral bender (Lee et al., 2010;Mohammadi et al., 1999;Wagner et al., 2005). For example, Chen et al. (2008) presented the helical actuator using the versatile technique of electrophoretic deposition. ...
This article presents a finite element analysis of a polarized piezoelectric tube driven by helical electrodes. It is thanks to a helical coordinate meshing and local coordinate system association with each element that the problem of piezoelectric coupling has been studied. The numerical results agree well with the experimental data without the need of compensation factors as in previous works. The developed model was used to determine the electromechanical coupling coefficients of the tubes in axial and torsional modes. The electromechanical coupling coefficient depends on the helical angle of the electrode. In the axial mode, electromechanical coupling coefficient goes through a maximum value of 25% when the helical angle of the electrode is close to 30°, while in the torsional mode, the maximum value of electromechanical coupling coefficient was reached at a helical angle near 60°. The analysis investigates the tube size effects and shows the potential uses of piezoelectric tubes as an actuator or energy harvesting device. The presented model could be used to analyze the electric fields in the tube during the polarization process or to analyze the mechanical stress (without any limitation due to Saint-Venant’s principle) imposed by the simplified analytical approaches available in the literature. The developed approach can also be used for theoretical analysis of the helical/spiral piezoelectric element.
... Compared with other actuating mechanisms, the strokes provided by piezoelectric technology are usually quite low. Wagner et al. [42] propose a 3D helical piezoceramic bender with applications such as loudspeaker. PZT multilayer helimorph structures have been fabricated to lower the required voltage and increase the resulting displacement: deformations up to 500 μm can be achieved with an applied voltage of 100 V and blocking forces of 1 N. ...
