Design, modeling, and experimental validation of a fully decoupled piezoelectrically actuated compliant nano-positioning stage

Multi-objective topology optimization of piezoelectric stick-slip actuators for design and performance analysis

Design, analysis and experimental research of a novel single-phase driven rod-type rotary piezoelectric actuator.

Texture-controlled electrostain response in PNN-PZT multilayer piezoelectric ceramic actuators enabled by asymmetric stacking strategy

Active vibration control of a smart sandwich plate via optimally located piezoelectric sensors and actuators

Model-based pre-compensator design for piezoelectric actuators based on physics guided neural network and physics-precision balanced training

High temperature stability in Li2CO3-doped PYN-PZT co-fired multilayer piezoelectric actuators

Abstract To mitigate the oscillations and backward motion exhibited by stick–slip piezoelectric actuators (PZTs) during operation and enhance their movement speed, this study proposes an field-programmable gate array (FPGA) based hybrid control method for high-precision positioning of bipedal stick–slip stepping PZTs. A composite control strategy is implemented to address hysteresis nonlinearity and achieve sub-micron positioning accuracy. First, a dynamic model integrating piezoelectric nonlinearity, compliant hinge dynamics, and friction effects is established to characterize the actuator’s motion. Second, the Classical-Prandtl–Ishlinskii model is adopted to describe hysteresis behavior, followed by constructing an inverse model to generate feedforward-compensated waveforms, which are output through a DAC controlled by the FPGA. Finally, to achieve dynamic error correction, the FPGA acquires real-time displacement feedback from the sensor via an ADC and dynamically outputs PID control parameters to adjust the driving waveform. Experimental results demonstrate that the compensated waveform improves single-step velocity by 26.9% compared to conventional sawtooth wave excitation. With closed-loop control, the system achieves a steady-state accuracy below 0.1 μm and a millisecond-level response time. This work presents an embedded control solution with high robustness and real-time performance, offering significant potential for applications in micro-electromechanical systems and ultra-precision positioning.

We present a compact multimodal endomicroscope that enables simultaneous fluorescence (FL) and optical coherence tomography (OCT) imaging. While current endoscopy techniques are effective for wide-area and rapid inspection, there is a growing demand for real-time precise diagnostics, including detailed tissue morphology and tumor invasion depth. Histological analysis through biopsy remains the diagnostic standard but involves a time-consuming process that can delay treatment decisions. Our approach integrates two complementary imaging modalities—FL for visualizing tissue morphology and OCT for cross-sectional imaging—within a single probe compatible with standard gastrointestinal endoscopic channels. The system employs a Lissajous scanning mechanism to achieve forward-viewing, uniform illumination, and high-speed imaging. A compact imaging probe is fabricated by assembling a composite fiber, piezoelectric tube actuator, and asymmetrically attached polymer stiffener in parallel, enabling combined fluorescence and optical coherence imaging with complementary performance characteristics. Real-time image reconstruction is implemented using parallel computing to support high-throughput data processing. Imaging experiments on phantom targets and ex-vivo animal tissues confirm the system’s capability to produce detailed, co-registered images of tissue morphology and structure. This technology offers a promising platform for enhancing diagnostic accuracy and enabling real-time decision-making in gastrointestinal endoscopy.

The paper represents both numerical simulations and experimental investigations of a piezoelectric active preload system that is foreseen to be applied to the active preload control system of rotors of ultrasonic piezoelectric motors. The investigated preload system is based on the piezoelectric multilayer actuator and disc-shaped spring, which is attached at end of the actuator. The total volume and mass of the preload system are 275 mm3 and 4.3 g, respectively. The results of investigations demonstrate strong agreement between the experimental and simulation data, showing nearly linear displacement and output force responses within an input voltage range of 20 V to 75 V in the frequency range from DC to 200 Hz. In the investigated ranges, the active preload system is able to ensure up to 1 N force with displacement amplitude up to 30 µm, which were obtained at a driving signal of 75 V. These results show that the investigated active preload system can replace passive preload devices in ultrasonic piezoelectric motors which are subjected to strict requirements in terms of their mass and mounting volume.

This paper proposes an adaptive fuzzy fixed-time control (AF-FxT-C) scheme for a piezoelectric-driven microinjector. The inherent hysteresis of the piezoelectric actuator is treated as an unknown nonlinearity. A fuzzy logic system is employed to approximate this hysteresis, along with other lumped disturbances, while an adaptive law is designed to improve approximation accuracy. To address the challenge of inconsistent initial states caused by frequent start-stop operations, a fixed-time control law is developed via a second-order backstepping approach. This guarantees that the upper bound of the system’s settling time is independent of the initial conditions, which is a claim rigorously substantiated by a theoretical stability analysis. The simulation and experimental results validate the effectiveness of the proposed method. The method also maintains robust tracking performance across reference signals of varying frequencies and amplitudes, demonstrating its potential for industrial microinjection applications.

Lithium-ion batteries (LIBs) remain the dominant technology for portable electronics, electric vehicles, and grid-level energy storage due to their high energy density, long cycle life, and favorable gravimetric and volumetric performance. Nonetheless, diffusion-limited transport phenomena—particularly lithium-ion mobility within the electrolyte and across electrode interfaces—constrain power delivery and fast-charging capability. These limitations are exacerbated under elevated current densities and temperature excursions, where undesired side reactions such as electrolyte decomposition, cathode–electrolyte interphase (CEI) instability, and solid electrolyte interphase (SEI) degradation accelerate. Traditional mitigation strategies, including advanced electrode chemistries, nanostructured materials, and novel electrolyte formulations, often face scalability barriers and introduce additional cost and synthetic complexity.In this work, we propose and experimentally validate a non-invasive, mechanically driven method to improve electrochemical transport processes in LIBs using ultrasonic wave excitation. The approach leverages acoustic streaming and localized perturbation effects to modulate mass transport phenomena, thereby reducing impedance and enhancing performance under high-rate operation. Importantly, we employ a fully integrated system architecture capable of transmitting ultrasonic energy into sealed commercial-format polymer pouch cells, while maintaining isothermal conditions. This enables clear differentiation between thermally induced and acoustically induced effects—a critical distinction often confounded in prior studies due to uncontrolled temperature rise associated with ultrasonic transducer heating.Our platform utilizes piezoelectric transducers operating in the 20 kHz frequency, coupled to lithium-ion cells through an acoustically matched solid waveguide to eliminate immersion in liquids, thus preserving packaging integrity and facilitating translation to real-world systems. Temperature control is achieved through embedded thermistors and an active thermal feedback loop, maintaining constant temperature during ultrasound application. Electrochemical performance was characterized through galvanostatic cycling, rate capability tests, and electrochemical impedance spectroscopy (EIS), supported by equivalent circuit modeling (ECM) and differential capacity analysisUpon ultrasonic activation, a reproducible and reversible reduction in both bulk and interfacial impedance components was observed. Charge-transfer resistance (Rct) decreased by up to 20.4% under optimized acoustic power conditions, correlating with improved rate performance and reduced overpotential during high-rate charging. The impedance reduction was found to scale with both vibration amplitude and exposure duration, but remained within safe mechanical thresholds to avoid structural damage to the cell. Removal of the ultrasound source restored baseline impedance values, confirming the non-destructive and tunable nature of the intervention.To assess the broader applicability of ultrasonic enhancement across chemistries, we extended this methodology to zinc–air batteries, which are similarly diffusion-limited due to slow oxygen reduction kinetics and viscous alkaline electrolytes. A piezoelectric ring actuator was affixed to the cathode shell of a button-type zinc–air battery to induce controlled ultrasonic fields. At an operating power of 150 W, a 36.5% increase in peak output power was achieved. Rating capacity increased by ~20%, and impedance spectra confirmed a reduction in electrolyte resistance and charge-transfer impedance. Optical microscopy images revealed the formation of a planer zinc metal surface with suppressed zinc dendrite, promoting electrode renewal and electrolyte diffusion.This work provides a systematic, multi-scale investigation into the interplay between acoustic energy and electrochemical transport in energy storage devices. By integrating precise thermal management, real-time impedance monitoring, and structure–function analysis, we demonstrate that ultrasonic excitation constitutes a scalable and energy-efficient approach to enhance battery performance. Unlike conventional strategies that require material re-engineering or formulation changes, this method preserves device architecture and chemistry, making it compatible with existing manufacturing platforms.Our findings offer a foundational understanding of acoustically induced transport enhancement and open new directions in battery performance modulation via mechanical energy. Future studies will investigate in situ acoustic field mapping, integration with battery management systems (BMS), and dynamic control of ultrasonic stimulation during fast charging protocols. Additionally, exploration of synergistic effects between ultrasound and advanced solid-state electrolytes or three-dimensional electrode architectures may yield further performance gains.

Abstract This study introduces a bio-inspired vibro-drilling system that harnesses bending resonance to improve penetration efficiency in granular soils. Inspired by the lateral undulation of sandfish, the probe combines a compliant polylactic acid (PLA) flexure joint with surface-bonded piezoelectric actuators to generate whirling bending motions independent of axial thrust and torque. Experimental modal analysis was conducted to identify the resonant bending modes of the system. Subsequently, finite-element analysis (FEA) was performed to visualize the dominant mode shapes and assess the influence of the compliant joint on soil fluidization. 
Experimental penetration tests indicated that the optimal bending resonance for rapid soil fluidization occurs at approximately 4400 Hz. 
Complementary FE analysis of the resonance modes revealed that the compliant PLA joint amplifies the bending resonance, leading to a tenfold increase in squared tip velocity. 
This enhanced motion facilitates greater transfer of vibrational energy to the surrounding soil particles, thereby improving fluidization efficiency. Whirling vibrations at approximately 4400 Hz reduce linear penetration force by 46.4\%. When combined with rotary drilling, bending vibrations also reduce penetration force by 31\% and the required torque by 12\% compared to a non-vibrating probe. These findings demonstrate that bio-inspired bending resonance significantly enhances energy transfer to soil particles, enabling compact, energy-efficient, and waterless drilling systems. This opens new opportunities for planetary subsurface prospecting, miniaturized low-power geotechnical probes for in-situ testing in resource-constrained environments such as the Moon and Mars, trenchless micro-drilling in urban environments, soft robotic systems for underground exploration or inspection, and drone- or rover-mounted penetration-based sensing.

Abstract This paper investigates the precise motion control of a surgical ear robot (VTA) using a piezoelectric ultrasonic actuator (PUA). The aim is to overcome the challenges of nonlinearity, uncertainties, and disturbances in PUA. For this purpose, a non-singular terminal sliding mode controller is designed along with a disturbance observer. Simulation results show that the designed controller is able to track the desired signal with very high accuracy and in a limited time. The tracking error quickly approaches zero and no chattering is observed in the system response. The performance of the proposed controller is compared with the results of other papers. The results show that the controller proposed in this paper has a lower tracking error than the existing methods. In particular, in the steady state, the tracking error in the proposed method reaches zero, while in the comparative methods, there is an error of several micrometers. The value of the integral absolute error (IAE) for the proposed method (0.0856) is calculated to be lower than that of the methods [41] (0.0996) and [43] (1.3631), which indicates the better performance of the proposed method. Also, the investigations show that the fast terminal sliding mode controller (first design) consumes less energy for tracking than the non-singular terminal sliding mode controller (second design).

Design and Performance Analysis of Radial Bending Resonant Piezoelectric Actuator with Staggered Motion Characteristics Inspired by Sea Urchin’s Teeth Morphology

Electrical stimulation (ES) is widely used in the field of myocardial tissue engineering. By ES and improving various parameters of conductive substrates, it is possible to change the differentiation and mechanical and electrophysiological characteristics of a single cardiomyocyte, thereby alleviating or curing diseases. In this paper, the mechanical and electrophysiological characteristics of cardiomyocytes under ES were studied by atomic force microscopy (AFM), and the electrical and mechanical characteristics of cardiomyocytes under ES were evaluated. The height change of the piezoelectric actuator along the z axis during the contraction-relaxation cycle was recorded so as to quantify the contractile force of cardiomyocytes in the constant force contact mode. The results showed that the height and action potential (AP) amplitude of cardiomyocytes increased with the increase of the electric field when the electric field intensity was less than 0.8 V cm-1, but when the electric field intensity was greater than 0.8 V cm-1, the trend was opposite. The statistical diagram of the relationship between the height and frequency of cardiomyocytes measured by experiments was inverted U-shaped, reaching the peak at about 2 Hz. In addition, with the increase of frequency, the action potential duration (APD) gradually shortens. The results show that when the current was less than 0.28 nA, the amplitude of the height and AP of cardiomyocytes increased with the increase of the current, but when the current was greater than 0.28 nA, the trend was opposite. At the same time, it was found that with the increase of the current intensity, the time for cardiomyocytes to produce the first action potential was shortened, and it tended to be consistent when the current was greater than 0.24 nA. By studying the effects of ES on the electrophysiological and mechanical properties of cardiomyocytes, we can better understand the mechanism and biological effects of ES on the organism. It is helpful for us to study and simulate the electric environment suitable for the growth and maturation of cardiomyocytes and tissues in vitro and provide a basic platform for further cell experiments such as establishing myocardial tissue models and drug screening in the future.

Piezoelectric actuators that leverage defect modes in phononic crystals (PnCs) have the capacity to significantly amplify longitudinal or flexural waves, rendering them a compelling option for nondestructive testing applications. However, conventional PnCs exhibit a deficiency in their inability to adapt their wave-propagation characteristics to changing environments. To address this limitation, the present study incorporates defective PnC-based bending wave actuators within elastic foundations, thereby facilitating mechanical tuning. An analytical model, founded upon the Euler–Bernoulli beam theory and formulated with transfer matrix and S parameter techniques, has been developed to capture both electroelastic coupling and foundation effects. Two practical configurations are examined: (1) a uniform foundation supporting the entire defective PnC, including the piezoelectric defect, and (2) a selective foundation supporting only the intact beams, leaving the defect region free. In both cases, the proposed analytical model accurately predicts the results in band structure and wave-actuation analyses, showing excellent agreement with COMSOL Multiphysics simulations. The following are the most significant findings: (1) the closed-form analytical model validated against COMSOL for rapid parametric design, (2) near-linear tuning of the bandgap and defect-band frequencies via foundation stiffness while retaining strong defect-mode-enabled energy localization, (3) robust defect-mode shapes that sustain large, symmetric strain fields for efficient bending-wave actuation, and (4) enhanced voltage-to-velocity actuation sensitivity and discovery of an additional low-frequency defect mode when the defect region is left unsupported.

This study presents a comprehensive analysis of the static and free vibration behavior of a functionally graded carbon nanotube-reinforced FGM (functionally graded material) cylindrical panel embedded in piezoelectric layers and subjected to simply supported boundary conditions. While earlier studies have mainly addressed rectangular plates and complete cylindrical shells, the present investigation focuses on cylindrical panels (imperfect cylindrical). The formulation is based on the three-dimensional theory of elasticity. The elastic modulus and density vary continuously through the thickness according to an exponential distribution function. The FG configuration for CNT is further categorized into four distinct distribution types that oriented along the radial direction. Previous investigations on complete cylindrical shells composed of functionally graded carbon nanotube-reinforced FGM have primarily employed energy-based methods to obtain solutions. In the present study, however, the problem is addressed within the rigorous framework of three-dimensional elasticity theory. The coupled electromechanical governing equations are analytically solved by employing a Fourier series expansion in the axial and circumferential directions, alongside the state-space method through the thickness coordinate. A detailed numerical study is conducted to investigate the influence of the material gradient index, CNT volume fraction, piezoelectric layer thickness, and mid-radius-to-thickness ratio of the FGM panel.

Fragmented thrombolytic actuators address the limited time window of thrombolysis agents and the risk of intimal injury from mechanical thrombectomy, emerging as a crucial method for rapid vascular recanalization. However, occluded vessels are often tortuous and narrow, imposing strict size constraints on the actuator. Moreover, the inability to assess thrombolysis efficacy in real-time during procedures impedes timely adjustments to control strategies for the actuator. To address these challenges, this study designs a conical piezoelectric actuator that employs high-frequency vibration in conjunction with a small dose of thrombolytics to fragment and accelerate thrombus dissolution. Firstly, structural parameters of the actuator are optimized using grey relational analysis combined with an improved entropy-weighting method, and the optimal design is prototyped and tested. Next, a real-time thrombolytic solution concentration detection algorithm based on an Improved Grey Wolf Optimizer–Support Vector Regression (IGWO-SVR) model is proposed. Finally, an experimental platform is constructed for validation and analysis. The results show that compared to the initial design, the optimized actuator has significantly improved kinematic and force performance, with the tip amplitude increasing by 42% and the output energy density reaching 3.3726 × 10−2 W/mm3. The IGWO-SVR model yields highly accurate, stable concentration estimates, with a coefficient of determination (R2) of 0.9987 and a root-mean-square error (RMSE) of 0.8118. This work provides a pathway toward actuator miniaturization and real-time thrombolysis monitoring, with positive implications for future clinical applications.

Piezoelectric synthetic jet actuators typically struggle to generate high-speed jets at low driving frequencies due to the coupling effect between jet frequency and jet intensity. This limitation to some extent restricts their application in flow control within low-speed flow fields. To address this issue, this study presents two methods of signal modulation. The effects of driving signal modulation on dual synthetic jet actuator (DSJA) characteristics were experimentally investigated. A laser displacement meter was used to measure the central point amplitude of the piezoelectric diaphragm, while the velocity at the exit of the DSJAs was measured using a hot-wire anemometer. The effects of signal modulation on the amplitude of the piezoelectric diaphragm, the maximum jet velocity, and the frequency domain characteristics of the dual synthetic jet (DSJ) were thoroughly analyzed. Experimental results demonstrate that driving signal modulation can enhance jet velocity at relatively low driving frequencies. The modulated DSJ exhibits low-frequency characteristics, rendering it suitable for flow control applications that require low-frequency jets. Furthermore, the coupling effect between jet frequency and jet intensity in the piezoelectric DSJA is significantly alleviated. Starting from the vibration displacement of the piezoelectric transducer (PZT), this paper systematically elaborates on the corresponding relationship between PZT displacement and the peak velocity at the jet outlet, and the “low-frequency and high-momentum jet generation method based on signal modulation” proposed herein is expected to break through the momentum–frequency coupling limitation of traditional piezoelectric dual-stenosis jet actuators (DSJAs) and enhance their application potential in low-speed flow control.