A novel monolithic piezoelectric actuated wire clamp is presented in this paper to achieve fast, accurate, and robust microelectronic device packaging. The wire clamp has compact, flexure-based mechanical structure and light weight. To obtain large and robust jaw displacements and ensure parallel jaw grasping, a two-stage amplification composed of a homothetic bridge type mechanism and a parallelogram leverage mechanism was designed. Pseudo-rigid-body model and Lagrange approaches were employed to conduct the kinematic, static, and dynamic modeling of the wire clamp and optimization design was carried out. The displacement amplification ratio, maximum allowable stress, and natural frequency were calculated. Finite element analysis (FEA) was conducted to evaluate the characteristics of the wire clamp and wire electro discharge machining technique was utilized to fabricate the monolithic structure. Experimental tests were carried out to investigate the performance and the experimental results match well with the theoretical calculation and FEA. The amplification ratio of the clamp is 20.96 and the working mode frequency is 895 Hz. Step response test shows that the wire clamp has fast response and high accuracy and the motion resolution is 0.2 μm. High speed precision grasping operations of gold and copper wires were realized using the wire clamper.

In the field of precision machining, the spindle-rolling bearing (SRB) system is widely used on the machine tool as one of the most fundamental and important components. The rotational error motions of the SRB system have significant effects on the machining accuracy (contour accuracy and surface roughness). Over the past decades, much work has been focused on the measurement of spindle balancing and rotational error motions, the vibrations response induced by the nonlinear stiffness and surface waviness of the bearing. However, the formative mechanism of the rotational error motions for the SRB system is not well understood. In this paper, the dynamic model of the SRB system considering the bearing nonlinearity is established. Seeking to reveal the effects of surface waviness of the bearing raceway, unbalance mass and disturbance force on the dynamic rotational error, the modeling method and formative mechanism of the dynamic rotational error for the SRB system is explored both theoretically and experimentally. Then, numerical simulation is performed to analyze the influence of the bearing raceway waviness, unbalance mass and disturbance force on the dynamic rotational error. An experimental setup is established based on a typical SRB system and a series of experiments are carried out. The experimental results are in good agreement with the theoretical and simulation results, which can demonstrate the feasibility and validity of the modeling method. Furthermore, this method can be effectively applied to the design and development phases of an SRB system to improve dynamic rotational accuracy.

To achieve cost-effective micro-/nano-displacement adjustment, this paper integrates the advantages of flexible hinge micro-/nano-displacement transmission. A linear stepper motor is utilized as the driving component to design and develop a high-precision, low-cost micro-/nano-positioning system. The structure, design, and working principles of the micro-/nano-positioning platform are introduced. The scaling factor model between micro-positioning platforms and nano-positioning platforms is analyzed. Static and dynamic models of flexible mechanisms have been established. The dimensions of the mechanical structure and the selection of motors are determined. The mechanical characteristics of the micro-/nano-positioning platform are validated through finite element analysis. To address the characteristic of increasing loads during the transmission process, an intelligent control system based on current feedback is designed and developed. The integration of drive and control provides a high level of system integration. Finally, experimental calibration was conducted to test the motion characteristics of the linear stepper motor-driven micro-/nano-positioning platform. It achieved a minimum displacement control resolution of 100 nm and demonstrated a certain level of stability.

Accurate beef cattle body measurement data are crucial for growth assessment, phenotypic analysis, breeding management, and precision livestock farming. Traditional manual measurements are labor-intensive, time-consuming, and likely to cause stress in animals, making it difficult to meet the demands of large-scale livestock farming. This paper employs a structured systematic literature review method, in accordance with the PRISMA 2020 guidelines, to summarize research progress in vision-based beef cattle body measurement. This paper focuses on reviewing technical approaches such as 2D image-based measurement, 3D measurement using RGB-D and LiDAR, and multi-view fusion. It analyzes key technologies including image segmentation, keypoint detection, point cloud processing, 3D reconstruction, and geometric calculations, and compares the advantages and disadvantages of different methods in terms of measurement accuracy, robustness, cost, and farm applicability. The results indicate that 2D image-based methods are low-cost and flexible to deploy but have limited expressiveness for 3D body measurement parameters; RGB-D and LiDAR methods can provide spatial information but are affected by point cloud noise, occlusion, equipment costs, and data processing complexity; multi-view fusion can improve the completeness of body surface information but places high demands on calibration, registration, and system integration. Current research still faces challenges such as a lack of public datasets, inconsistent annotation standards, uncertainty regarding ground truth, insufficient cross-ranch generalization validation, and limited practical applications. Future research should focus on developing standardized datasets, conducting cross-scenario validation, advancing multimodal perception, creating lightweight models, and applying edge computing to drive the evolution of visual body measurement toward continuous monitoring and intelligent decision-making.

CORRIGENDUM: Design and control of a large-stroke piezoelectric micro-gripper based on flexible crank-slider mechanism (2026 J. Micromech. Microeng. 36 065003), Cui, Liangyu, Liu, Jingwei, Zhang, Xuanqi, Deng, Xiaofan

Piezoelectric ceramic actuator-driven micro-grippers represent a key technology for micromanipulation and micro-assembly processes at micro/nano scales. To address the limited stroke of piezoelectric ceramic actuators, this paper proposes a design and analysis method for a large-stroke micro-gripper based on a flexible crank-slider mechanism, along with experimental validation. Kinematic equations were established to investigate the relationship between the displacement amplification ratio and the dimensions/positions of crank-slider linkages, deriving geometric conditions for achieving high amplification ratios. The influence of flexure hinge posture on transmission efficiency was analyzed, and a compact microgripper structure was designed using straight-beam flexure hinges. Finite element simulations were employed to analyze the micro-gripper's amplification ratio, input stiffness, and modal characteristics. Experimental studies on nonlinear compensation for piezoelectric ceramic actuators were conducted, evaluating the micro-gripper's stroke, amplification ratio, and resolution. Simulation and experimental results demonstrate close alignment between measured parameters and theoretical values. The proposed flexible crank-slider-based microgripper features a simple, compact structure, achieves an amplification ratio of 32 times, and delivers a stroke of 640μm.