• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1993.05a
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• pp.15-18
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• 1993

Piezoelectric Actuator and electrostrictive Actuator samples were fabricated using PMN-PT-PZ system ceramics with Barium substitution, and the strain properties of them investigated. The largest Piezoelectric coefficient and electromechanical coupling coefficient were observed at sintering temperature $1250^{\circ}C$, Barium 0.05 mol %. The strain of poled samples is observed twice highly then unpoled ones, and the former showed larger hysteresis in strain then the latter, too. Poled multilayered actuator samples showed considerable strain.

• 제어로봇시스템학회:학술대회논문집
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• 2002.10a
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• pp.120.4-120
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• 2002

$\textbullet$ In order to operate EP actuator, high voltage is applied to that. $\textbullet$ Our previous control algorithm for an EP actuator was PI method with constant gain. $\textbullet$ But this Control method is limitation such as rising time, steady-state error, and settling time. $\textbullet$ A neural network algorithm is proposed for improvement of performance. $\textbullet$ To do this, neural network algorithm changes the gain of PI control. $\textbullet$ In order to efficient drive EP actuator, the gain is changed at some point. $\textbullet$ Neural network method improve the performance of operation.

• Journal of the Korean Ceramic Society
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• v.26 no.6
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• pp.802-810
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• 1989

The temperature dependence of piezoelectric strain constant and the electric field induced strain are investigated as a function of PT in 0.5[xPT-(1-x)PZ]-0.5PNN ceramics. The piezoelectric strain constant d31 has the highest value(360$\times$10-12m/V) at PT=0.68. The temperature dependence of d31 is improved as Curie temperature of sample is increased, and the electric field dependence of induced strain is decreased with the coercive field increased. This ceramic system shows both piezoelectric effect and electrostrictive effect under the applied electric field. The piezoelectric of tetragonal phase is higher than that of rhombohedral phase, and the magnitude of electrostrictive constant is appeared in the order of morphotropic, rhombohedral and tetragonal phase. The piezoelectric strain constant with applied field must be considered theelectrostrictive effect due to 90$^{\circ}$domain wall displacements, and the displacement of bimorph type actuator agrees with the calulated value well.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1997.10a
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• pp.307-310
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• 1997

In case of environment requiring safety such as human body and requiring flexible shape, a conventional mechanical actuator system does not satisfy requirement. Therefore, in order to solve this problem, a research of various smart material such as EAP (Electro Active Polymer), EAC (Electro Active Ceramic) and SMA (Shape Memory Alloy) is in progress. Recently, the highest preferring material among various smart material is EP (Electrostictive Polymer), because it has very fast response time, poerful force and large displacement. The previous researches have been studied properties of polymer and simple control, but present researches are studied a polymer actuator. An EP (Electostrictive Polymer) actuator has properties which change variably as shape and environmental condition. Therefore, in order to coincide with a user's purpose, it is important not only to decide a shape of actuator and mechanical design but also to investigate a efficient controller. In this paper, we constructed the control logic with an adaptive fuvy algorithm which depends on the physical properties of EP that has a dielectric constant depending on time.

• Journal of Ceramic Processing Research
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• v.13 no.spc2
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• pp.282-285
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• 2012

Lead-free (Bi0.5Na0.41K0.09)TiO3 (BNKT) multilayer ceramic actuators were prepared using tape-casting and screen-printing techniques. Co-firing behavior of BNKT/AgPd laminates was examined as a function of sintering temperature. It was found that co-firing induced bending and electrical properties were very sensitive to sintering condition. By optimizing sintering conditions, lead-free electrostrictive multilayer actuators with normalized strain Smax/Emax of 266 pm/V have been successfully fabricated, which is promising for lead-free actuator applications.

• Composites Research
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• v.27 no.1
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• pp.25-30
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• 2014

The actuation performance of an EADE (Electro-active dielectric elastomer) is studied as functions of thinner content, thickness and types of the dielectric elastomer such as natural (NR), acrylonitrile-butadiene (NBR), and silicon (KE-12) rubbers. With a decrease in elastomer thickness ($1{\rightarrow}0.5{\rightarrow}0.25{\rightarrow}0.1{\rightarrow}0.05$ mm) and an increase in thinner content ($0{\rightarrow}30{\rightarrow}50$ phr), the actuating displacement of KE-12 elastomer is increased, however their breakdown occurs at low voltage. For the same thickness (1 mm), the displacement of KE-12 elastomer shows a higher value (2.24 mm) compared to that of NR or NBR at the same applied voltage of 25 kV. The KE-12 has the lowest elastic modulus and the NBR has the highest one among the tested elastomers. However, the displacement of NBR elastomer is higher compared to that of NR because of high dielectric constant. It is found that the important factors of EADE actuator are a thickness, modulus and dielectric constant of the elastomer.