This paper presents the design and development of a new flexure-based XYZ micropositioner with a hybrid kinematic configuration. A piezoelectric-driven Z stage is embedded into a parallel-kinematic XY stage actuated by two voice coil motors. The XYZ micropositioner features a sizeable workspace with a compact architecture, which benefits from employing deployable mechanisms and mixed actuators. One uniqueness is that the Z-axis crosstalk error of the XYZ micropositioner is compensated by the closed-loop motion control of the Z stage, which achieves a constant vertical position of the center platform when performing planar motion tasks. Analytical models have been derived based on fixed-guided beam theory to assess the driving stiffness of the mechanism. The finite element analysis is carried out to verify the accuracy of the derived models. A prototype system of the XYZ micropositioner is fabricated with the dimension of 116 mm$\times$116 mm$\times$45 mm (i.e., 216 mm$\times$216 mm$\times$45 mm with actuators). Experimental results indicate that it obtains a workspace of 4.15 mm$\times$4.06 mm$\times$0.04 mm with a crosstalk of less than 1% among the three axes. With the active control of the Z-axis position, the vertical crosstalk error has been dramatically reduced from 7.333 to 1.719$\mu$m. The proposed design provides a promising approach to enable pure planar motion for ultrahigh precision applications requiring optical or electron focusing, such as electron beam lithography.Note to Practitioners—Flexure-based micropositioners are essential for the semiconductor manufacturing process, atomic force microscopy, and microassembly, due to their high precision and reliability. Many applications demand a planar motion without vertical crosstalk to realize ultrahigh precision operation. For the first time, this paper proposes the concept design of an XYZ micromanipulator by utilizing a Z stage to compensate for the vertical crosstalk error generated by the X/Y-axis motion, which is not considered and is difficult to realize in conventional XY flexible stage design. The simulation has confirmed the effectiveness of the derived analytical models. The XYZ micropositioner’s static and dynamic characteristics are then experimentally evaluated on a fabricated prototype. The travel stroke, coupling displacement, driving stiffness, and resonant frequency have been tested. Experimental results reveal that the active compensation has significantly diminished the Z-axis parasitic errors. The performance comparison results validate the superiority of the proposed concept design.

This paper proposes the concept design of a novel XY compliant parallel manipulator (CPM) with spatial configuration, which is beneficial to promote the performance of the XY CPM. Evolved from a planar configuration, a spatial compliant parallelogram flexure is devised as the basic module structure. Then, a mirror-symmetric XY CPM adopting spatial layout is proposed based on four-prismatic-prismatic (4-PP) parallel mechanism. The prototypes are fabricated by 3D printing for testing. The performance analysis and verification is conducted through theoretical modeling, finite element simulation, and experimental study. For comparison study, a planar XY CPM with similar mechanism is also developed. Results show that the proposed XY CPM with spatial configuration provides the benefits of smaller plane footprint, large working stroke, and enhanced load-bearing capacity as compared to the planar one. It is appropriate for precise positioning scenarios, like soft-contact lithography, which require high loading capacity and great compactness.

The flexure-based XYZ micropositioner with hybrid configuration has become more prevalent due to the characteristics of less mechanism decoupling and high motion precision. However, traditional mechanism design suffers from a large plane occupation with Z stage stacking, which leads to a low space-utilization efficiency. To address this issue, a novel conceptual design is proposed in this paper by integrating a spatially structured XY stage and an embedded Z stage together. After completing the design of the mechanism, the driving stiffness of the stage in three axes is evaluated by the mechanics analysis. Then, the model is verified by performing finite element analysis simulation study and experimental test. The theoretical model, simulation results, and experimental data indicate a good agreement. Experimental results show that the proposed flexure-based XYZ micropositioner can deliver a stroke of$\boldsymbol{4.15 \text{mm} \times 4.06 \text{mm} \times 0.04}$mm with a physical size of$\boldsymbol{116 \text{mm} \times 116 \text{mm} \times 45 \text{mm}. }$The performance comparison reveals that it has a superior space-utilization efficiency. In consideration of the feasibility of the proposed conceptual design, it provides a reference for diversified and refined design of XYZ micropositioners.

In this paper, a new piezoelectric-actuated biaxial compliant microgripper with long strokes is proposed for automatically gripping and rolling tiny rigid objects. In order to improve the working stroke and maintain a compact footprint, a counter-side distributed two-stage lever amplifier with parallelogram mechanism is introduced. Based on the pseudo-rigid body model, analytical models of the displacement amplification ratio, input stiffness, and natural frequency of the left- and right-sided gripper mechanism are established. Structural optimization and performance simulation of the proposed microgripper mechanism are carried out with finite element analysis simulation. A prototype microgripper has been fabricated for open-loop and closed-loop tests to verify its working capabilities. The clamping and rubbing experiments show that the designed microgripper can grasp and rub an optical fiber with the diameter of 200$\mu \text{m}$for rolling over 45°. The developed microgripper has a promising application in precision micromanipulation fields such as optical fiber alignment. Note to Practitioners—This work is motivated by the requirement of designing a biaxial microgripper with both a large working stroke and compact structure for complex operation in optical fiber alignment. Through a series of open-loop and closed-loop experiments on the developed prototype, it is demonstrated that the proposed dual-axis microgripper has superior working performance. The clamping stroke and rubbing stroke of the gripper are$251.2~\mu \text{m}$and$225.0~\mu \text{m}$, respectively. The first two natural frequencies of the gripper are 350.63 Hz and 603.37 Hz, which correspond to the working modes of the right-side and left-side gripper mechanisms, respectively. The closed-loop experimental results show that the resolution of output displacement of the gripper is close to$1.2~\mu \text{m}$and the resolution of the clamping force is 3 mN. As compared with the reported microgrippers in previous work, the designed mechanism exhibits both a large working stroke and high resonant frequency for ensuring the reliability and rapidity of micromanipulation task.

This article proposes the concept design of a novel bio-inspired dual-axis compliant micromanipulator with millimeter working strokes dedicated to fiber alignment. It subtly mimics the gripping and rubbing function of human hand consisting of forefinger, purlicue, and thumb. As compared with traditional dual-axis gripper, its advantages lie in millimeter-level stroke, bidirectional rotation, less slippage, and comprehensive force sensing. To achieve dexterous and reliable manipulation, a two-degree of freedom flexible decoupling mechanism and a displacement reversing mechanism based on the leaf-shaped flexible hinge are introduced. Analytical models are derived to assess the statics and dynamics properties of the micromanipulator, which are verified by conducting finite-element analysis simulation study. A prototype driven by two voice coil motors is fabricated for experimental testing. Three high-precision strain gauges with temperature compensation are glued on the sensitive region to measure the gripping force and rubbing force. Experimental results show that the gripping stroke and rubbing stroke of the manipulator are up to 2.3 and 2.1 mm, respectively. For operating a custom-made fiber flag with a diameter of 200$\mu$m, a rotation stroke of more than 1000$^{\circ }$has been achieved, which cannot be realized by previous work with the same level of compact mechanism design.

High-performance and multi-function micromanipulator is favored by micromanipulation and microassembly systems. In this paper, a piezoelectric-actuated biaxial asymmetrical compliant micromanipulator is designed for gripping and rolling small targets. Parallel operation with large stroke is realized by the left and right sides of the micromanipulator with a well-designed multi-stage flexible amplifying mechanism. The pseudo-rigid-body model and the instantaneous center method are adopted to determine the displacement amplification ratio of the micromanipulator. The accuracy and applicability of the displacement amplification model are verified by conducting simulation studies with finite element analysis (FEA). It is shown that the clamping stroke and rubbing stroke of the micromanipulator are 357.94 μm and 245.48 μm, respectively. Furthermore, the stiffness, gripping force, and natural frequency of the micromanipulator are also evaluated by FEA simulations. The results demonstrate that the designed biaxial compliant micromanipulator has the ability of performing delicate and dexterous operations on small targets such as optical fiber.