Showing papers on "Piezoelectric sensor published in 2010"
TL;DR: In this paper, the authors present various optimization criteria used by researchers for optimal placement of piezoelectric sensors and actuators on a smart structure, including modal forces/moments applied by actuators, maximizing deflection of the host structure, minimizing control effort/maximizing energy dissipated, maximizing degree of controllability, and minimizing degree of observability.
Abstract: This article presents in a unified way, the various optimization criteria used by researchers for optimal placement of piezoelectric sensors and actuators on a smart structure. The article discusses optimal placement of piezoelectric sensors and actuators based upon six criteria: (i) maximizing modal forces/moments applied by piezoelectric actuators, (ii) maximizing deflection of the host structure, (iii) minimizing control effort/maximizing energy dissipated, (iv) maximizing degree of controllability, (v) maximizing degree of observability, and (vi) minimizing spill-over effects. Optimal piezoelectric sensor and actuator locations on beam and plate structures for each criterion and modes of interest are presented in a tabular form. This technical review has two objectives: (i) practicing engineers can pick the most suitable philosophy for their end application and (ii) researchers can come to know about potential gaps in this area.
246 citations
TL;DR: In this paper, the authors deal with the optimization of piezoelectric actuators and sensors locations for active vibration control, and two modified optimization criteria are used, ensuring good observability or controllability of the structure, and considering residual modes to limit the spillover effect.
178 citations
TL;DR: The paper reviews the recent applications of piezoelectric materials in structural health monitoring and repair conducted by the authors and examines the basic principle and the current development of the technique.
Abstract: The paper reviews the recent applications of piezoelectric materials in structural health monitoring and repair conducted by the authors. First, commonly used piezoelectric materials in structural health monitoring and structure repair are introduced. The analysis of plain piezoelectric sensors and actuators and interdigital transducer and their applications in beam, plate and pipe structures for damage detection are reviewed in detail. Second, an overview is presented on the recent advances in the applications of piezoelectric materials in structural repair. In addition, the basic principle and the current development of the technique are examined.
125 citations
TL;DR: In this paper, a new piezoelectric energy harvester for harnessing energy from flow-induced vibration is developed, which converts flow energy into electrical energy by piezo-lectric conversion with oscillation of a piezolectric film.
Abstract: A new piezoelectric energy harvester for harnessing energy from flow-induced vibration is developed. It converts flow energy into electrical energy by piezoelectric conversion with oscillation of a piezoelectric film. A finite element model is developed in order to estimate the generated voltage of the piezoelectric laminate subjected to a distributed load. Prototypes of the energy harvester are fabricated and tested. Experimental results show that an open circuit output voltage of 2.2 Vpp and an instantaneous output power of 0.2 µW are generated when the excitation pressure oscillates with an amplitude of 1.196 kPa and a frequency of about 26 Hz. The solution of the generated voltage based on the finite element model agrees well with the experiments. Based on the finite element model, the effects of the piezoelectric film dimensions, the fluid pressure applied to the harvester and types of piezoelectric layer on the output voltage of the harvester can be investigated.
121 citations
TL;DR: In this article, a distributed sensor network is proposed for structural health monitoring using guided waves in plate-like structures, where each piezoelectric sensor acts in turn as an actuator and a local linear neural network is used to model the nonlinear dispersion curves.
Abstract: A new approach for structural health monitoring using guided waves in plate-like structures has been developed. In contrast to previous approaches, which mainly focused on isotropic or quasi-isotropic plates, the proposed algorithm does not assume any simplifications regarding anisotropic wave propagation. Thus, it can be used to improve the probability of detection. In this paper the mathematical background for damage localization in anisotropic plates will be introduced. This is an extension of the widely known ellipse method. The formalism is based on a distributed sensor network, where each piezoelectric sensor acts in turn as an actuator. The automatic extraction of the onset time of the first waveform in the differential signal in combination with a statistical post-processing via a two-dimensional probability density function and the application of the expectation-maximization algorithm allows a completely automatic localization procedure. Thus, multiple damages can be identified at the same time. The present study uses ultrasonic signals provided by the spectral element method. This simulation approach shows good agreement with experimental measurements. A local linear neural network is used to model the nonlinear dispersion curves. The benefit of using a neural network approach is to increase the angular resolution that results from the sparse sensor network. Furthermore, it can be used to shorten the computational time for the damage localization procedure.
119 citations
01 Oct 2010-Precision Engineering-journal of The International Societies for Precision Engineering and Nanotechnology
TL;DR: A review of voltage, charge and capacitor insertion methods for driving piezoelectric actuators is presented in this article, where the authors show that the amount of hysteresis and creep could be minimized to a large extent when a piezel actuator is driven using a charge input.
Abstract: A piezoelectric actuator consists of ceramic material that expands or contracts when a positive or a negative potential voltage signal is applied. The displacement of a piezoelectric actuator is commonly controlled using a voltage input due to its ease of implementation. However, driving a piezoelectric actuator using a voltage input leads to the non-linear hysteresis and creep. Hysteresis and creep are undesirable characteristics which lead to large errors when a piezoelectric actuator is used in positioning applications. The amount of hysteresis and creep could be minimized to a large extent when a piezoelectric actuator is driven using a charge input. Another method which substantially reduces hysteresis and creep involves the insertion of a capacitor in series with a piezoelectric actuator which is driven using a voltage input. A review of voltage, charge and capacitor insertion methods for driving piezoelectric actuators is presented in this paper. Experimental results, for a piezoelectric actuator driven using the above three methods, are presented to validate the facts presented in this review.
116 citations
TL;DR: In this article, two models were developed to characterize the Lamb wave propagation properties of orthotropic panels, and experiments were conducted to empirically characterize the wave propagation behavior in a manufactured laminate.
Abstract: Damage detection in composite laminated panels using Lamb waves is demonstrated with an innovative use of a sensor array and processing algorithm. Two models were developed to characterize the Lamb wave propagation properties of orthotropic panels. Predictions of the dispersion relations were made for a fiber-reinforced composite laminate. Experiments were conducted to empirically characterize the wave propagation behavior in a manufactured laminate. Piezoelectric patches were used as sensors and actuators in the experiments. Comparisons were made between analytical predictions and experimental results, which demonstrate that the higher order model captured essential wave propagation behavior at frequencies of interest. Sensor arrays and associated processing were used for wavenumber decomposition and filtering of the Lamb wave modes. Composite laminates were manufactured with an embedded defect to simulate inter-ply delamination. Experiments were conducted to detect the presence of delamination damage in...
96 citations
TL;DR: In this article, the effect of the size and shape of a piezoelectric sensor on the harvested energy was investigated, and it was shown that significant increases in harvested energy may be obtained by optimising the sensor design.
Abstract: Energy harvesting for the purpose of powering low power electronic sensor systems has received explosive attention in the last few years. A common device uses the piezoelectric effect for a cantilever beams at resonance to harvest ambient vibration energy. However most of these devices have a rectangular piezoelectric patch covering all or part of the beam. This paper considers the optimum design of such a device, and in particular investigates the effect that the size and shape of piezoelectric sensor has on the harvested energy. It is shown that significant increases in harvested energy may be obtained by optimising the sensor design.
94 citations
TL;DR: Current research issues in the development of efficient analysis models and their efficient numerical implementation for smart piezoelectric laminated structures are discussed and future challenge lies in developing efficient theories capable of predicting the interlaminar transverse shear stresses in hybrid laminates directly from the constitutive equations.
Abstract: Current research issues in the development of efficient analysis models and their efficient numerical implementation for smart piezoelectric laminated structures are discussed in this paper. The improved zigzag theories with a layerwise quadratic variation of electric potential have emerged as the best compromise between accuracy and cost for hybrid composite, sandwich and FGM beams and plates. The concept of associating surface potentials to electric nodes and internal potentials to physical nodes is very effective in modeling the equipotential electroded surfaces. Unified formulations for shear and extension mode actuation, and modeling of piezoelectric composite actuators and sensors are discussed. Future challenge lies in developing efficient theories capable of predicting the interlaminar transverse shear stresses in hybrid laminates directly from the constitutive equations.
92 citations
TL;DR: In this article, a hybrid spectral element was developed for modeling piezoelectric actuator-induced high-frequency wave propagation in thin plates. And the hybrid element is proven to be an efficient technique for modeling PZT-induced (PZT: lead zirconate titanate) wave propagation.
Abstract: Use of surface-mounted piezoelectric actuators to generate acoustic ultrasound has been demonstrated to be a key component of built-in nondestructive detection evaluation (NDE) techniques, which can automatically inspect and interrogate damage in hard-to-access areas in real time without disassembly of the structural parts. However, piezoelectric actuators create complex waves, which propagate through the structure. Having the capability to model piezoelectric actuator-induced wave propagation and understanding its physics are essential to developing advanced algorithms for the built-in NDE techniques. Therefore, the objective of this investigation was to develop an efficient hybrid spectral element for modeling piezoelectric actuator-induced high-frequency wave propagation in thin plates. With the hybrid element we take advantage of both a high-order spectral element in the in-plane direction and a linear finite element in the thickness direction in order to efficiently analyze Lamb wave propagation in thin plates. The hybrid spectral element out-performs other elements in terms of leading to significantly faster computation and smaller memory requirements. Use of the hybrid spectral element is proven to be an efficient technique for modeling PZT-induced (PZT: lead zirconate titanate) wave propagation in thin plates. The element enables fundamental understanding of PZT-induced wave propagation.
82 citations
TL;DR: In this paper, the scaling laws of electrostatic, electromagnetic and piezoelectric transduction for generating motion at the micro scale were investigated, employing scaling laws and a reasoned consideration of the di!culties in motor fabrication and design using each method.
Abstract: Though miniaturization and mass production via integrated circuit fabrication techniques have transformed our society, the methods have yet to be successfully applied to the generation of motion, and as a consequence the many potential benefits of microrobotics has yet to be realized. The characteristics of electrostatic, electromagnetic and piezoelectric transduction for generating motion at the micro scale is considered, employing scaling laws and a reasoned consideration of the di!culties in motor fabrication and design using each method. The scaling analyses show that electrostatic, electromagnetic and piezoelectric actuators all have comparable force scaling characteristics of F / L 2 ; if one employs permanent magnets, electromagnetic forces do not scale as F / L 4 . Though the torque, ! , of piezoelectric ultrasonic motors scale rather poorly with ! / L 4 , they have the clear advantage of possessing torque amplitudes some two orders of magnitude larger than motors employing the other transduction schemes at the micro scale.
TL;DR: A post-CMOS compatible fabrication process for piezoelectric sensors and actuators on silicon using only standard CMOS metals is reported and microcantilever actuators are demonstrated.
Abstract: Piezoelectric materials are widely used for microscale sensors and actuators but can pose material compatibility challenges. This paper reports a post-CMOS compatible fabrication process for piezoelectric sensors and actuators on silicon using only standard CMOS metals. The piezoelectric properties of aluminum nitride (AlN) deposited on titanium (Ti) by reactive sputtering are characterized and microcantilever actuators are demonstrated. The film texture of the polycrystalline Ti and AlN films is improved by removing the native oxide from the silicon substrate in situ and sequentially depositing the films under vacuum to provide a uniform growth surface. The piezoelectric properties for several AlN film thicknesses are measured using laser doppler vibrometry on unpatterned wafers and released cantilever beams. The film structure and properties are shown to vary with thickness, with values of d33f, d31 and d33 of up to 2.9, −1.9 and 6.5 pm V−1, respectively. These values are comparable with AlN deposited on a Pt metal electrode, but with the benefit of a fabrication process that uses only standard CMOS metals.
TL;DR: In this paper, a theoretical Lamb wave tuning curve (LWTC) of a specific transducer size is obtained for selective actuation and sensing of Lamb wave modes, the sizes of the transducers and the driving frequency of the input waveform should be tuned.
Abstract: Surface-bonded lead zirconate titanate (PZT) transducers have been widely used for guided wave generation and measurement. For selective actuation and sensing of Lamb wave modes, the sizes of the transducers and the driving frequency of the input waveform should be tuned. For this purpose, a theoretical Lamb wave tuning curve (LWTC) of a specific transducer size is generally obtained. Here, the LWTC plots each Lamb wave mode' amplitude as a function of the driving frequency. However, a discrepancy between experimental and existing theoretical LWTCs has been observed due to little consideration of the bonding layer and the energy distribution between Lamb wave modes. In this study, calibration techniques for theoretical LWTCs are proposed. First, a theoretical LWTC is developed when circular PZT transducers are used for both Lamb wave excitation and sensing. Then, the LWTC is calibrated by estimating the effective PZT size with PZT admittance measurement. Finally, the energy distributions among symmetric and antisymmetric modes are taken into account for better prediction of the relative amplitudes between Lamb wave modes. The effectiveness of the proposed calibration techniques is examined through numerical simulations and experimental estimation of the LWTC using the circular PZT transducers instrumented on an aluminum plate.
TL;DR: Recorded AFM images show a considerable reduction in image distortion due to the proposed control method, enabling artifact free AFM imaging at a speed of 122 lines per second with a standard piezoelectric tube scanner.
TL;DR: In this article, low computing-cost methods for analysing the instant variation of the chamber pressure, directly obtained from the electric signal provided by a traditional piezoelectric sensor, are presented.
TL;DR: For the first time an absolute validation of a magnetostrictive EMAT model has been achieved; the model is able to successfully predict the wave amplitude dependence on significant parameters: the static bias field, the driving current amplitude, and the excitation frequency.
Abstract: The noncontact nature of electromagnetic acoustic transducers (EMATs) offers a series of advantages over traditional piezoelectric transducers, but these features are counter-balanced by their relatively low signal-to-noise ratio and their strong dependence on material properties such as electric conductivity, magnetic permeability, and magnetostriction. The implication is that full exploitation of EMATs needs detailed modeling of their operation. A finite element model, accounting for the main transduction mechanisms, has been developed to allow the optimization of the transducers. Magnetostriction is included and described through an analogy with piezoelectricity. The model is used to predict the performance of a simple EMAT: a single current-carrying wire, parallel to a bias magnetic field generating shear horizontal waves in a nickel plate close to it. The results are validated against experiments. The model is able to successfully predict the wave amplitude dependence on significant parameters: the static bias field, the driving current amplitude, and the excitation frequency. The comparison does not employ any arbitrary adjustable parameter; for the first time an absolute validation of a magnetostrictive EMAT model has been achieved. The results are satisfactory: the discrepancy between the numerical predictions and the measured values of wave amplitude per unit current is less than 20% over a 200 kHz frequency range. The study has also shown that magnetostrictive EMAT sensitivity is not only a function of the magnetostrictive properties, because the magnetic permeability also plays a significant role in the transduction mechanism, partly counterbalancing the magnetostrictive effects.
TL;DR: In this article, a three translational degrees of freedom (DOF) complaint perpendicular parallel micro-manipulator (PPMM) with monolithic structure is presented, and the relationship between voltage value of piezoelectric actuator and output displacement of end-effector is obtained base on the IPSD model.
TL;DR: In this paper, a method for deriving the governing equations that describe a system's vibration suppression based on the equilibrium of force principle and using an equivalent mechanical model of a piezoelectric element is described.
TL;DR: In this paper, the authors developed micromechanics and finite element models to study the electroelastic properties of an active nanocomposite, as a function of the aspect ratio and alignment of the piezoelectric filler.
Abstract: Piezoelectric materials offer exceptional sensing and actuation properties; however, they are prone to breakage and difficult to apply on curved surfaces in their monolithic form. One method of alleviating these issues is through the use of?0?3 nanocomposites, which are formed by embedding piezoelectric particles into a polymer matrix. Material of this class offers certain advantages over monolithic materials; however, it has seen little use due to its low coupling. Here we develop micromechanics and finite element models to study the electroelastic properties of an active nanocomposite, as a function of the aspect ratio and alignment of the piezoelectric filler. Our results show that the aspect ratio is critical for achieving high electromechanical coupling, and with an increase from?1 to?10 at?30% volume fraction of piezoelectric filler the coupling can increase to 60 times its initial value and achieve a bulk composite coupling as high as 90% for a pure PZT-7A piezoelectric constituent.
TL;DR: In this article, the authors developed a topology optimization formulation for dynamic design of piezoelectric laminated plates aiming at actuators, sensors, and energy harvesting applications.
Abstract: Sensors and actuators based on piezoelectric plates have shown increasing demand in the field of smart structures, including the development of actuators for cooling and fluid-pumping applications and transducers for novel energy-harvesting devices. This project involves the development of a topology optimization formulation for dynamic design of piezoelectric laminated plates aiming at piezoelectric sensors, actuators and energy-harvesting applications. It distributes piezoelectric material over a metallic plate in order to achieve a desired dynamic behavior with specified resonance frequencies, modes, and enhanced electromechanical coupling factor (EMCC). The finite element employs a piezoelectric plate based on the MITC formulation, which is reliable, efficient and avoids the shear locking problem. The topology optimization formulation is based on the PEMAP-P model combined with the RAMP model, where the design variables are the pseudo-densities that describe the amount of piezoelectric material at eac...
TL;DR: Based on higher-order shear plate theory and elastic piezoelectric theory, the nonlinear geometric and constitutive relations of the functionally graded plate were established, and then the non linear motion equations of the pieziolectric functional graded plate are obtained through Hamilton's variational principle as discussed by the authors.
01 Jan 2010-Precision Engineering-journal of The International Societies for Precision Engineering and Nanotechnology
TL;DR: In this paper, a model reference adaptive control scheme based on hyperstability theory is developed for a moving stage system driven by a PZT actuator for improving the trajectory tracking performance.
Abstract: Piezoelectric (PZT) actuators having the characteristic of infinitely small displacement resolution are popularly applied as actuators in precision positioning systems. Due to its nonlinear hysteresis effect, the tracking control accuracy of the precision positioning system is difficultly achieved. Hence, it is desirable to take hysteresis effect into consideration for improving the trajectory tracking performance. In this paper, a model reference adaptive control scheme based on hyperstability theory is developed for a moving stage system driven by a PZT actuator. It is worth emphasizing that the controller can be constructed without a nonlinear hysteresis dynamic equation to compensate the hysteresis effect. According to simulation results, the tracking error was only nanometer order. Through experimental examinations, the tracking performance was obtained as precision as ten nanometers order which is the resolution limitation of the measurement system. The effectiveness of the proposed adaptive control scheme was validated.
TL;DR: In this article, a finite element model for the analyzis of active sandwich laminated plates with a viscoelastic core and laminated anisotropic face layers, as well as piezoelectric sensor and actuator layers is presented.
Abstract: In this article, we present a new finite element model for the analyzis of active sandwich laminated plates with a viscoelastic core and laminated anisotropic face layers, as well as piezoelectric sensor and actuator layers. The model is formulated using a mixed layerwise approach, by considering a higher order shear deformation theory to represent the displacement field of the viscoelastic core and a first-order shear deformation theory for the displacement field of the adjacent laminated anisotropic face layers and exterior piezoelectric layers. Control laws are implemented and the model is validated using reference solutions from the literature, and a benchmark application is proposed.
TL;DR: In this paper, two conditions that the three penalty exponents must satisfy for stable convergence are derived for one-dimensional problems and their effectiveness for twodimensional problems is investigated for static analysis of piezoelectric actuators.
TL;DR: An enhancement of the energy harvesting process using a nonlinear processing of the output voltage of piezoelectric actuators is proposed, and it is suggested that this improves the energy conversion and reduces the sensitivity to frequency drifts.
Abstract: In the first part of the paper, a single degree-of-freedom model of a vibrating membrane with piezoelectric inserts is introduced and is initially applied to the case when a plane wave is incident with frequency close to one of the resonance frequencies. The model is a prototype of a device which converts ambient acoustical energy to electrical energy with the use of piezoelectric devices. The paper then proposes an enhancement of the energy harvesting process using a nonlinear processing of the output voltage of piezoelectric actuators, and suggests that this improves the energy conversion and reduces the sensitivity to frequency drifts. A theoretical discussion is given for the electrical power that can be expected making use of various models. This and supporting experimental results suggest that a nonlinear optimization approach allows a gain of up to 10 in harvested energy and a doubling of the bandwidth. A model is introduced in the latter part of the paper for predicting the behavior of the energy-harvesting device with changes in acoustic frequency, this model taking into account the damping effect and the frequency changes introduced by the nonlinear processes in the device.
TL;DR: In this paper, an efficient finite element (FE) model for the active vibration control response of smart laminated beams integrated with electroded piezoelectric sensors and actuators is presented.
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.
01 Dec 2010
TL;DR: In this paper, the authors presented the micro-fabrication and testing of a CMOS-compatible high-performance piezoelectric inertial power generator with aligned solder-bonding and thinning of bulk PZT pieces on Si.
Abstract: This paper presents the micro-fabrication and testing of a CMOS-compatible high-performance piezoelectric inertial power generator. This is believed to be the first wafer-level micro-scale generator integrating a bulk piezoelectric ceramic, PZT. The technology offers advantages in fabrication flexibility and device performance over existing piezoelectric thin film deposition methods. The process involves aligned solder-bonding and thinning of bulk PZT pieces on Si. By conserving the bulk piezoelectric properties of the PZT material, high generator output voltage and high output impedance are obtained, simplifying rectification and regulation. Additional benefits of this process include the capability to obtain thick (5µm to 100µm) piezoelectric films without chemical patterning. Here, we describe a harvester with a Si proof mass, which generates 0.15µW from an input acceleration of 0.1g at 263Hz, and 10.2µW from an input acceleration of 2g at 252Hz. The unpackaged active volume of the generator (beam + mass) is 12.1mm3. The fabricated device has the highest Normalized Power Density for a PZT-based MEMS harvester reported to date, to the authors' knowledge.
TL;DR: In this paper, a piezoelectric device based on a cantilever with an extended auxiliary part that forms a right angle with the basic part is presented, and theoretical analyses and experiments support that, by using such a device, uniform strain distribution can be obtained, and thus, the materials can be used more efficiently.
Abstract: This paper reports a piezoelectric device based on a cantilever with an extended auxiliary part that forms a right angle with the basic part. Theoretical analyses and experiments support that, by using such a device, uniform strain distribution in piezoelectric element surfaces can be obtained, and thus the piezoelectric materials can be used more efficiently. A piezoelectric element on a right-angle cantilever can generate a useful power twice that of a traditional cantilever under the same strain limitation.
TL;DR: In this paper, a piston-type micromirror with a stroke of up to 20 µm at 20 V was designed, fabricated and characterized using a silicon-on-insulator wafer with integrated piezoelectric actuators.
Abstract: A novel piston-type micromirror with a stroke of up to 20 µm at 20 V formed out of a silicon-on-insulator wafer with integrated piezoelectric actuators was designed, fabricated and characterized. The peak-to-valley planarity of a 2 mm diameter mirror was better than 15 nm, and tip-to-tip tilt upon actuation less than 30 nm. A resonance frequency of 9.8 kHz was measured. Analytical and finite element models were developed and compared to measurements. The design is based on a silicon-on-insulator wafer where the circular mirror is formed out of the handle silicon, thus forming a thick, highly rigid and ultra-planar mirror surface. The mirror plate is connected to a supporting frame through a membrane formed out of the device silicon layer. A piezoelectric actuator made of lead–zirconate–titanate (PZT) thin film is structured on top of the membrane, providing mirror deflection by deformation of the membrane. Two actuator designs were tested: one with a single ring and the other with a double ring providing bidirectional movement of the mirror. The fabricated mirrors were characterized by white light interferometry to determine the static and temporal response as well as mirror planarity.
TL;DR: In this article, a low cost, low power but multifunctional wireless sensor node is presented for the impedance-based SHM using piezoelectric sensors, which is based on the TinyOS platform for operation, and users can take MATLAB interface for the control of the sensor node through serial communication.
Abstract: In this paper, a low cost, low power but multifunctional wireless sensor node is presented for the impedance-based SHM using piezoelectric sensors. Firstly, a miniaturized impedance measuring chip device is utilized for low cost and low power structural excitation/sensing. Then, structural damage detection/sensor self-diagnosis algorithms are embedded on the on-board microcontroller. This sensor node uses the power harvested from the solar energy to measure and analyze the impedance data. Simultaneously it monitors temperature on the structure near the piezoelectric sensor and battery power consumption. The wireless sensor node is based on the TinyOS platform for operation, and users can take MATLAB interface for the control of the sensor node through serial communication. In order to validate the performance of this multifunctional wireless impedance sensor node, a series of experimental studies have been carried out for detecting loose bolts and crack damages on lab-scale steel structural members as well as on real steel bridge and building structures. It has been found that the proposed sensor nodes can be effectively used for local wireless health monitoring of structural components and for constructing a low-cost and multifunctional SHM system as "place and forget" wireless sensors.