This paper presents a comprehensive review of mechanical design and synthesis methods for piezo-actuated compliant micro-positioning stages, which play an important role in areas where high precision motion is required, including bio-robotics, precision manufacturing, automation, and aerospace. Unlike conventional rigid-link mechanisms, the motion of compliant mechanisms is realized by using flexible elements, whereby deformation requires no lubrication while achieving high movement accuracy without friction. As compliant mechanisms differ significantly from traditional rigid mechanisms, recent research has focused on investigating various technologies and approaches to address challenges in the flexure-based micro-positioning stage in the aspects of synthesis, analysis, material, fabrication, and actuation. In this paper, we reviewed the main concepts and key advances in the mechanical design of compliant piezo-actuated micro-positioning stages, with a particular focus on flexure design, kineto-static modeling, actuators, material selection, and functional mechanisms including amplification and self-guiding ones. We also identified the key issues and directions for the development trends of compliant micro-positioning stages.

Based on the background of atomic force microscope (AFM) driven by piezoelectric actuators (PEAs), this paper proposes a sliding mode control coupled with an inverse Bouc–Wen (BW) hysteresis compensator to improve the positioning performance of PEAs. The intrinsic hysteresis and creep characteristics degrade the performance of the PEA and cause accuracy loss. Although creep effect can be eliminated by the closed-loop control approach, hysteresis effects need to be compensated and alleviated by hysteresis compensators. For the purpose of dealing with the estimation errors, unmodeled vibration, and disturbances, a sliding mode control with perturbation estimation (SMCPE) method is adopted to enhance the performance and robustness of the system. In order to validate the feasibility and performance of the proposed method, experimental studies are carried out, and the results show that the proposed controller performs better than a proportional-integral-derivative (PID) controller at 1 and 2 Hz, reducing error to 1.2% and 1.4%, respectively.

The Preisach model is a typical scalar mathematical model used to describe the hysteresis phenomena, and it attracts considerable attention. However, parameter identification for the Preisach model remains a challenging issue. In this paper, an improved particle swarm optimization (IPSO) method is proposed to identify Preisach model parameters. Firstly, the Preisach model is established by introducing a Gaussian−Gaussian distribution function to replace density function. Secondly, the IPSO algorithm is adopted to Fimplement the parameter identification. Finally, the model parameter identification results are compared with the hysteresis loop of the piezoelectric actuator. Compared with the traditional Particle Swarm Optimization (PSO) algorithm, the IPSO algorithm demonstrates faster convergence, less calculation time and higher calculation accuracy. This proposed method provides an efficient approach to model and identify the Preisach hysteresis of piezoelectric actuators.

Mechanical metastructures consisting of periodic cells with adjustable output force charactersitics and ranges have received increasing attention in recent years owing to its unique capability to tune mechanical properties such as stiffness and Poisson’s ratio etc. In this paper, we present the design, simulation, and experimental characterization of a mechanical metastructure that realizes customized constant force output. The metastructure consists of periodic constant force units that are formed by combining a positive and negative stiffness element. Notably, the force unit also contains a unique flexure design with solid and hollow pins to reduce the lateral stress by 50%, which allows for precise control of the output force. By using a programmable design method, the force unit forms 2D and 3D metastructures via parallel and tendem stacking. Simulations were performed to optimize the design and predict the device performance. Finally, experiments were devised and performed to verify the simulation results of the metastructures. The promising results warrant the wide application of the new mechanical metastructure as well as the programmable design method, such as low-pass mechanical filters, noise and vibration cancellation devices etc.

Micro-positioning stages, which are capable to meet the emerging industrial trend for performing various kind of micro manipulation and micro-assembly tasks, are crucial tools to miniaturize products under ultra-high precision. The current main practice is to specifically tailor a monolithic positioning stage design for one kind of micro-manipulation application. However, the design and fabrication of such a specific flexure based micro-positioning stage are expensive in both time and financial investment. In order to increase the flexibility and functionality of micro-positioning stages, this study proposes a novel reconfigurable planar micro-positioning stages platform based on different function modules. Functional model based approach is developed to divide one micro-positioning stage into a set of functionally independent sub-models, that allows flexible composition resulting in a adjustable new stage. The robustness of the proposed platform is demonstrated using some typical micro-positioning stages benchmarking cases. The effectiveness of assembly using flexible function modules are verified to show the benefits of the proposed design platform for reconfigurable micro-positioning stages.