• Journal of Sensor Science and Technology
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• v.32 no.1
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• pp.22-30
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• 2023

Innovative and advanced technologies, including robots, augmented reality, virtual reality, the Internet of Things, and wearable medical equipment, have largely emerged as a result of the rapid evolution of modern society. For these applications, pressure monitoring is essential and pressure sensors have attracted considerable interest. To improve the sensor performance, several new designs of pressure sensors have been researched based on resistive, capacitive, piezoelectric, optical, and triboelectric types. In particular, optical pressure sensors have been actively studied owing to their advantages, such as robustness to noise and remote sensing capability. Herein, a review of recent research on optical pressure sensors with self-powered sensing, remote sensing, high spatial resolution, and multimodal sensing capabilities is presented from the viewpoints of design, fabrication, and signal processing.

• Structural Engineering and Mechanics
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• v.42 no.2
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• pp.211-228
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• 2012

Present study deals with the development of finite element based solution methodology to investigate active control of dynamic response of delaminated composite shells with piezoelectric sensors and actuators. The formulation is based on first order shear deformation theory and an eight-noded isoparametric element is used. A coupled piezoelectric-mechanical formulation is used in the development of the constitutive equations. For modeling the delamination, multipoint constraint algorithm is incorporated in the finite element code. A simple negative feedback control algorithm coupling the direct and converse piezoelectric effects is used to actively control the dynamic response of delaminated composite shells in a closed loop employing Newmark's time integration scheme. The validity of the numerical model is demonstrated by comparing the present results with those available in the literature. A number of parametric studies such as the locations of sensor/actuator patches, delamination size and its location, radius of curvature to width ratio, shell types and loading conditions are carried out to understand their effect on the transient response of piezoceramic delaminated composite shells.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.17 no.1
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• pp.31-38
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• 2004

PMN-PT, a piezoelectric single crystal, has many useful applications such as sensors and actuators. In this paper, all the elastic, piezoelectric, and dielectric constants of the PMN-32％PT single crystals were measured by the resonance method. For the rhombohedral symmetry, a total of twelve independent material constants were measured such as six elastic compliance constants at constant electric field, two dielectric constants at constant stress, and four piezoelectric constants d. Seven sets of crystal samples of each different geometry were prepared for the measurement of length-thickness extensional, thickness extensional, radial, length extensional and thickness shear modes of vibration, respectively. In order to check the validity of the measurement, experimental impedance spectrum of the PMN-PT crystal was compared with numerical data spectrum calculated with the measured material constants. The good agreement between the two spectra confirmed validity of the results in this paper.

• Composites Research
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• v.14 no.3
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• pp.90-98
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• 2001

In this survey paper, the application research and development trends of piezoelectric materials are reviewed. Advantages and disadvantages of piezoelectric materials, and the recent research to overcome the drawbacks are discussed. The market of piezoelectric sensors and actuators in USA, Japan, and EU is surveyed with several examples. In Korea, the analytical research concerning piezoelectric materials is active but the developments of devices and equipments are not so active, and the investment in this field is necessary.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.06a
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• pp.251-255
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• 2003

This paper presents the design, fabrication, and calibration of a piezoelectric polymer-based sensorized microgripper. Electro discharge machining technology is employed to fabricate super-elastic alloy based micro gripper. It is tested to present improvement of mechanical performance. For integration of force sensor on the micro gripper, the sensor design based on the piezoelectric polymer PVDF film and fabrication process are presented. The calibration and performance test of force sensor integrated micro gripper are experimentally carried out. The force sensor integrated micro gripper is applied to perform fine alignment tasks of micro opto-electrical components. It successfully supplies force feedback to the operator through the haptic device and plays a main role in preventing damage of assembly parts by adjusting the teaching command.

• Journal of KSNVE
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• v.9 no.1
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• pp.70-76
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• 1999

This paper presents a pseudo-sensor-output-feedback(PSOF) method for the vibration suppression of the flexible piezoelectric smart structures. This method reduces the modeling errors using pseudo sensors in the output equation formulation. It also reduces computation time in practice. since the output equation does not need the state observer required in the state space equation. Experimental works are performed for the validation of theoretical predictions with the piezoelectric sensor and actuator bonded on the cantilever beam. An algorithm based on the sliding mode control theory is developed and analyzed for the robustness to the modeling errors and parameter uncertainties. This study also discusses the characteristics of the active and semi-active systems.

• Proceedings of the KSME Conference
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• 2001.06a
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• pp.435-440
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• 2001

Piezoelectric solids such as PZT and PLZT have been widely used as sensors and actuators for various smart systems. One of the problems arising in actuator applications is that a larger actuation force needs to be produced from a small system. This naturally leads to local electric field or stress concentration and thereby resulting in a nonlinear behavior inside the system, Hence, it becomes more important to predict the nonlinear behavior of piezoelectric solids. In this paper we investigate the mechanism of nonlinear behavior in those materials and suggest a constitutive and finite element model. The calculation results obtained from the model seem to be qualitatively consistent with experiments.

• Transactions of the Society of Information Storage Systems
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• v.1 no.1
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• pp.73-77
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• 2005

In this paper, a new silicon nitride cantilever integrated with silicon heater and piezoelectric sensor has been firstly developed to improve the uniformity of the initial bending and the mechanical stability of the cantilever array for thermo-piezoelectric SPM(scanning probe microscopy) -based data storages. This nitride cantilever shows thickness uniformity less than $2\%$. Data bits of 40 nm in diameter were recorded on PMMA film. The sensitivity of the piezoelectric sensor was 0.615 fC/nm after poling the PZT layer. For high speed operation, 128${\times}$128 probe array was developed.

• Structural Engineering and Mechanics
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• v.43 no.2
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• pp.163-177
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• 2012

This paper presents a LMI(linear matrix inequality)-based fuzzy approach of modeling and active vibration control of geometrically nonlinear flexible plates with piezoelectric materials as actuators and sensors. The large-amplitude vibration characteristics and dynamic partial differential equation of a piezoelectric flexible rectangular thin plate structure are obtained by using generalized Fourier series and numerical integral. Takagi-Sugeno (T-S) fuzzy model is employed to approximate the nonlinear structural system, which combines the fuzzy inference rule with the local linear state space model. A robust fuzzy dynamic output feedback control law based on the T-S fuzzy model is designed by the parallel distributed compensation (PDC) technique, and stability analysis and disturbance rejection problems are guaranteed by LMI method. The simulation result shows that the fuzzy dynamic output feedback controller based on a two-rule T-S fuzzy model performs well, and the vibration of plate structure with geometrical nonlinearity is suppressed, which is less complex in computation and can be practically implemented.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2002.04a
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• pp.453-460
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• 2002

Piezoelectric solids such as PZT and PLZT have been widely used as sensors or actuators for various smart structural systems. The main problem occurring in the applications is that a larger and larger actuation force is required to maximize the function of the system. This naturally leads to local concentrations of electric or stress fields near crack tips or geometric irregularities and thereby results in a nonlinear behavior of the system Hence, it becomes more important to Predict the nonlinear behavior of piezoelectric solids In this Paper we investigate the micro-mechanism of nonlinear behavior in piezoelectric materials and propose constitutive equations. The calculation results obtained from an associated finite element Program are shown to be qualitatively consistent with experiments.