Piezoelectric sensor

About: Piezoelectric sensor is a research topic. Over the lifetime, 7127 publications have been published within this topic receiving 115903 citations.

Bending behavior of piezoelectric curved actuator

Abstract: Bending behaviors of both a piezoelectric curved bi-morph actuator and a functional gradient piezoelectric curved actuator are studied and compared. The exact solutions of both mechanical and electrical fields of the actuators are obtained based fully on the theory of elasticity. It is found that non-zero normal stresses exist in the gradient piezoelectric curved actuator when the actuator is subjected to an external voltage, which is different from the results obtained in our previous works on the gradient piezoelectric flat actuator. It is also proved that the internal stresses are drastically reduced although the deflection of the gradient curved actuator is quite small. The present analytical solutions are compared with the FEM results and a good agreement is found.

Fabrication and characterization of piezoelectric micromachined ultrasonic transducers with thick composite PZT films

Abstract: Ferroelectric microelectromechanical systems (MEMS) has been a growing area of research in past decades, in which ferroelectric films are combined with silicon technology for a variety of applications, such as piezoelectric micromachined ultrasonic transducers (pMUTs), which represent a new approach to ultrasound detection and generation. For ultrasound-radiating applications, thicker PZT films are preferred because generative force and response speed of the diaphragm-type transducers increase with increasing film thickness. However, integration of 4- to 20-/spl mu/m thick PZT films on silicon wafer, either the deposition or the patterning, is still a bottleneck in the micromachining process. This paper reports on a diaphragm-type pMUT. A composite coating technique based on chemical solution deposition and high-energy ball milled powder has been used to fabricate thick PZT films. Micromachining of the pMUTs using such thick films has been investigated. The fabricated pMUT with crack-free PZT films up to 7-/spl mu/m thick was evaluated as an ultrasonic transmitter. The generated sound pressure level of up to 120 dB indicates that the fabricated pMUT has very good ultrasound-radiating performance and, therefore, can be used to compose pMUT arrays for generating ultrasound beam with high directivity in numerous applications. The pMUT arrays also have been demonstrated.

Dynamics of delaminated composite plates with piezoelectric actuators

Abstract: A ree ned higher-order-theory-based e nite element model is developed for modeling the dynamic response of delaminated smart composite plates. The theory assures an accurate description of displacement e eld and the satisfaction of stress-free boundary conditions at all free surfaces including delamination interfaces. A nonlinear induced strain model is used. Vibration control is obtained through piezoelectric layers bonded on the composite plate. The theory is implemented using a e nite element technique, which allows the incorporation of practical geometries and boundary conditions, various sizes, and locations of delaminations, as well as discrete sensors and actuators. The resulting model is shown to agree well with published experimental data. Signie cant changes in dynamic properties are observed due to the presence of delamination.

Active vibration control of piezoelectric laminated beams with electroded actuators and sensors using an efficient finite element involving an electric node

Abstract: This paper presents an efficient finite element (FE) model for the active vibration control response of smart laminated beams integrated with electroded piezoelectric sensors and actuators. The FE model is based on an efficient layerwise theory with a quadratic variation of electric potential across the piezoelectric layers. The beam element has two conventional nodes and one electric node, which has no physical coordinate. The electric potential degrees of freedom (DOF) at the electroded piezoelectric surfaces are attached to the electric node which is connected to multiple elements belonging to the same electroded surface. This models the equipotential surface of the electroded sensors and actuators conveniently, and eliminates the cumbersome task of averaging the electric DOF over the surface. The control system is designed using a reduced-order modal state space model. The constant gain velocity feedback (CGVF) and optimal control strategies are studied for smart composite and sandwich beams with single-input–single-output (SISO) and multi-input–multi-output (MIMO) configurations under step and impulse excitations. The numerical study for CGVF control is performed on cantilever smart beams with both conventionally and 'truly' collocated actuators and sensors. The reasons for experimentally observed instability in CGVF control with conventional collocated sensors and actuators is explained. The effect of multiple segmentation of electrodes on the control performance is investigated.