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- 摘要
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Realization of a infrared detector free of bandwidth limit based on quartz crystal tuning fork
摘要： A new type of photoelectric detector based on a standard quartz crystal tuning fork (QCTF) with resonant frequency of ～32 kHz is developed for infrared spectroscopy applications. Analogous to the photoelectric effect of traditional semiconductor detectors, we utilize the piezoelectric effect of the QCTF to gauge the light intensity. To demonstrate this technique, the spectral absorption features of C2H2 molecule have been recorded and compared with a commercial mercury cadmium-telluride (MCT) detector. The proposed detection technique may pave a new way towards developing a new type of photodetector without bandwidth limit and complicated cryogenic cooling.
关键词： Infrared detector,Piezoelectric effect,QCTF,Laser spectroscopy
更新于2025-09-23 15:23:52
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Application of the hybrid complex variable method to the analysis of a crack at a piezoelectric-metal interface
摘要： A plane strain problem for an electrically conducting interface crack between linear transversely isotropic piezoelectric and isotropic elastic conductor materials under remote mechanical loading is considered. The attention is focused on a hybrid complex variable method which combines the Stroh formalism for piezoelectric materials with the Muskhelishvili formalism for conducting isotropic elastic materials. This method is illustrated in detail for the open crack model and the contact zone crack model. Using special presentations of mechanical quantities via sectionally analytic functions, a combined Dirichlet–Riemann and Hilbert boundary value problem is formulated and solved analytically. Stress intensity factors as well as the crack tip energy release rate are found in a clear analytical form. Furthermore, transcendental equations for the determination of the realistic contact zone length and the location of the first interpenetration point have been obtained. A significant influence of the external mechanical loading on the crack opening and the stresses as well as the contact zone and interpenetration region lengths is observed. The dependencies of the mentioned values on the intensities of the mechanical loading are presented in tables and associated diagrams.
关键词： electrically conducting interface crack,Piezoelectric-metal joint,contact zone,complex variable method
更新于2025-09-23 15:23:52
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Novel interfacial bulk heterojunction technique for enhanced response in ZnO nanogenerator
摘要： In this paper, a direct sustainable approach for the development of n-ZnO:p-CuO heterojunction (ZCH) through a simple grinding is reported to be an effective technique to enhance the piezoelectric performance of ZCH/PDMS nanocomposite-based nanogenerator (ZP-PNG). We have first optimized the best concentration for ZnO/PDMS nanocomposite for the realization of the piezoelectric nanogenerator. Later, with the same configuration, we implemented a novel, simple, facile, frugal and inexpensive technique to fabricate ZCH. The heterojunction results in the improved charge transfer characteristics, low capacitance and charge nullification contributing to the enhanced piezoelectric output. This reflects in the improvement of the peak to peak piezoelectric potential of the device from 2.7 V to 9V. The instantaneous max power density was found to be 0.2 mW/m2.The device can work as a force sensor with improved sensitivity of 1.7 V/N compared to 1.05 V/N of the intrinsic device. The device being systematically studied for load matching, and capacitor charging to demonstrate the practicability of the device. Furthermore, we tested our device to harness the biomechanical energy from day to day life activities. Finally, the device was used to fabricate sustainable piezoelectric based smart urinal (PSU) systems for low-income group countries.
关键词： composite,heterojunction,sustainable smart sensors,piezoelectric,ZnO
更新于2025-09-23 15:23:52
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An Eco-friendly Flexible Piezoelectric Energy Harvester That Delivers High Output Performance is Based on Lead-Free MASnI3 Films and MASnI3-PVDF Composite Films
摘要： An environmentally-friendly lead-free methylammonium tin iodide (MASnI3) perovskite is successfully synthesized using a facile approach of an antisolvent-assisted collision technique under room ambient conditions, which results stability within 24 h under ambient room conditions. The phase transition of MASnI3 from tetragonal to cubic is first observed at ~ 30 °C. Polycrystalline MASnI3 films reveal a high dielectric constant of ~ 65 at 100 kHz, a low-leakage current density of 7 × 10-7 A cm-2 at 50 kV cm-1, well-developed P-E hysteresis loops, and a high piezoelectric coefficient (d33) of 20.8 pm V-1. The MASnI3 piezoelectric energy nanogenerator (PENG) shows an output voltage of ~ 3.8 V and an output current density of 0.35 μA cm-2. To enhance the piezoelectric output performance, the MASnI3 films are composited with an environmentally friendly PVDF polymer that had a porous structure. The PVDF-MASnI3 composite based-PENG reveals a maximum output voltage of ~ 12.0 V and current density of ~ 4.0 μA cm-2. A green light-emitting diode (LED) using the PVDF-MASnI3 PENGs is instantly lighted without need of a storage device, and long-term stability of the composite PENGs is validated for 90 days. This simple and cost-effective solution process is feasible for the fabrication of large-scale, high-performance, and environmental-friendly PENGs based on lead-free organic-inorganic perovskites to extensively implicate in medical and biomechanical applications.
关键词： Dielectric property,Lead-free MASnI3,PVDF-MASnI3 composite PENGs,Piezoelectric energy,Antisolvent-assisted collision technique
更新于2025-09-23 15:23:52
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Inversion-free force tracking control of piezoelectric actuators using fast finite-time integral terminal sliding-mode
摘要： The major hurdles to control the force created by piezoelectric actuators (PEAs) are originated from its strong nonlinear behaviors which include hysteresis, creep, and vibration dynamics. To achieve an accurate, fast and robust force tracking performance without using complicated modeling and parameter identification of PEAs, this paper presents a practical direct force control scheme. The proposed controller is based on two core approaches: 1) fast finite-time integral terminal sliding mode (FFI-TSM) which allows fast convergence and high accuracy to the closed-loop system without control chattering; and 2) an inverse-model-free compensation, named force-based time-delayed estimation (FBTDE) which offers significant robustness with minimum use of plant dynamics information. The finite-time stability of the overall closed-loop system is proven through the Lyapunov's method. The proposed force tracking controller is implemented on the PEA system driving a variable physical damping actuator mechanism. The overall accuracy, convergence speed, and robustness of the proposed controller are validated under various experimental scenarios. Comparative experimental results are particularly presented to verify the effectiveness of the FFI-TSM term and the FBTDE term.
关键词： Inversion-free force control,Piezoelectric actuators (PEAs),Time-delayed control (TDC),Terminal sliding mode
更新于2025-09-23 15:23:52
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[IEEE 2018 IEEE 13th Annual International Conference on Nano/Micro Engineered and Molecular Systems (NEMS) - Singapore, Singapore (2018.4.22-2018.4.26)] 2018 IEEE 13th Annual International Conference on Nano/Micro Engineered and Molecular Systems (NEMS) - Self-Powered, High-Sensitive Human Cutaneous Activities Sensor
摘要： A self-powered piezoelectric sensor based on lead-free (K,Na)NbO3 (KNN) thin film for human health monitoring is presented. The sensor is fabricated on a flexible substrate and exhibits high sensitivity and stability. It can detect various physiological signals such as pulse, respiration, and body movement. The results demonstrate its potential for wearable health monitoring applications.
关键词： piezoelectric sensor,KNN thin film,health monitoring,lead-free,flexible substrate,wearable
更新于2025-09-23 15:22:29
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[SEMA SIMAI Springer Series] Recent Advances in Differential Equations and Applications Volume 18 || Optimal Design of Piezoelectric Microactuators: Linear vs Non-linear Modeling
摘要： The main point of this work is the comparison between linear and geometrically non-linear elasticity modeling in the field of piezoelectric actuators fabricated at the micro-scale. Manufacturing limitations such as non-symmetrical lamination of the structure or minimum length scale are taken into account during the optimization process. The robust approach implemented in the problem also reduces the sensitivity of the designs to small manufacturing errors.
关键词： Large displacements,Electrode profile,Piezoelectric actuators,Heterogeneous bimorph,Topology optimization
更新于2025-09-23 15:22:29
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Size-Dependent Buckling and Vibrations of Piezoelectric Nanobeam with Finite Element Method
摘要： In the present paper, a finite element method is used to study the vibrations and buckling of a piezoelectric nanobeam. The beam theory used here is Bernoulli–Euler model. In order to achieve the goal, first, the governing equations of the piezoelectric nanobeam were obtained via the Hamilton principle, based on the higher-order theory such as modified couple stress. The shape functions were embedded in these equations, and the matrix form of the equations was obtained. In other words, the governing equations were discretized by the finite element method. By calculating the matrix form of equations, mass matrices, mechanical stiffness and electrical stiffness of the beam were obtained. It should be noted that when calculating stiffness matrices, first, the definition of a new element must be added to the effects of the electric field in the elements of the beam, and the effects of the gradient of strain should be added in the form of non-classical matrix to the stiffness matrix. With the aid of these critical load matrices, the buckling force and voltage and the natural frequency of the piezoelectric nanobeam have been calculated. Numerical results show that this method can involve the size effects.
关键词： Size effect,Piezoelectric,Buckling voltage,Couple stress theory,Free vibration,Buckling load
更新于2025-09-23 15:22:29
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Modes of vibration, stability and internal resonances on non-linear piezoelectric small-scale beams
摘要： This paper presents a non-linear piezoelectric size-dependent Rayleigh’s beam model, based on modified couple stress theory, a non-classical continuum theory that is sensitive to the size effect. Hamilton principle is employed to determine the partial differential governing equations and the boundary conditions. Free periodic vibrations are studied, with the goal of investigating the modes of vibration of piezoelectric small-scale beams in the non-linear regime, a study that appears to be lacking in the literature. The method of multiple scales and a shooting method are applied to solve the equations of motion; the stability of the solutions computed by the shooting method is investigated. A hinged-hinged beam is chosen as an example to delineate the non-linear size dependent free vibration behaviour. For the first time in this specific problem, secondary branches due to bifurcations are found. An important novelty of the work is that these secondary branches are determined using the shooting method, which does not suffer from the drawbacks of popular alternatives, as perturbation methods and the method of harmonic balance.
关键词： Piezoelectric,Modified couple stress,Non-linear modes of vibration,Small scale beams
更新于2025-09-23 15:22:29
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[IEEE 2018 IEEE International Ultrasonics Symposium (IUS) - Kobe, Japan (2018.10.22-2018.10.25)] 2018 IEEE International Ultrasonics Symposium (IUS) - A Hybrid 3D Thermal / 1D Piezoelectric Finite Element Model for Rapid Simulation of FBAR Filter Response Under High Power
摘要： The increasingly stringent power requirements imposed on BAW filter technologies has made coupling between thermal and piezoelectric physics relevant to the design process. Existing lumped filter models do not account for the effect of a 3D temperature distribution over each resonator. Here we report a new finite element based method for rapid simulation of filter response under high power that captures the effect of heat flow within the filter die as well as its path through the PCB to thermal ground.
关键词： thermo-piezoelectric,BAW,self-heating,nonlinear,FBAR,FEM,fully coupled
更新于2025-09-23 15:22:29