Precision positioning systems with large working stroke (millimeter or more) and micro/nano-scale positioning resolution are widely required in both scientific research and industries. For this kind of applications, piezoelectric materials based actuators show unique advantages and have been widely employed. To overcome the demerit of the limited working stroke for single piezoelectric element, various stepping motion principles have been proposed in the past years, and accordingly, stepping piezoelectric actuators with various structures have been designed and evaluated. This review is aimed to summarize the recent developments and achievements in stepping piezoelectric actuators with large working stroke. Especially, the emphasis is on three main types of stepping piezoelectric actuators, i.e., inchworm type, friction-inertia type, and parasitic type. The motion principles of these three types of piezoelectric actuators and the corresponding developments of various actuators are discussed respectively, followed by pointing out the existing problems in these three types of piezoelectric actuators and proposing some potential research directions in this topic. It is expected that this review is helpful for relevant researchers to understand stepping motion principles as well as piezoelectric actuators, and to successfully select and design stepping piezoelectric actuators for specific applications.

Stepping piezoelectric actuators with large working stroke for nano-positioning systems: A review

A trapezoid-type stick–slip piezoelectric linear actuator using a right circular flexure hinge mechanism was proposed, designed, fabricated, and tested with the aim of accomplishing linear driving based on stick–slip motion. The angle adjustment of the trapezoid beam was used for generating lateral motion on the driving foot of the flexure hinge mechanism. A method of tuning the lateral motion of the flexure hinge mechanism was discussed. Based on the finite-element method, a proper angle of the trapezoid beam was obtained. The analysis results proved that asymmetrical flexure hinge mechanism can increase static friction force in slow extension stage and decrease kinetic friction force in quick contraction stage by lateral motion of the driving foot. A prototype was fabricated and its experimental system was established. The mechanical output experiments showed that the prototype achieved maximum output velocity and load of 5.96 mm/s and 3 N at a voltage of 100 V $p-p$ and a frequency of 500 Hz, respectively.

A Novel Trapezoid-Type Stick–Slip Piezoelectric Linear Actuator Using Right Circular Flexure Hinge Mechanism

The design and control of a novel piezoelectric actuated compliant microgripper is studied in this paper to achieve fast, precise, and robust micro grasping operations. First, the microgripper mechanism was designed to get a large jaw motion stroke. A three-stage flexure-based amplification composed of the homothetic bridge and leverage mechanisms was developed and the key structure parameters were optimized. The microgripper was manufactured using the wire electro discharge machining technique. Finite element analysis and experimental tests were carried out to examine the performance of the microgripper mechanism. The results show that the developed microgripper has a large amplification factor of 22.6. Dynamic modeling was conducted using experimental system identification, and the displacement and force transfer functions were obtained. The position/force switching control strategy was utilized to realize both precision position tracking and force regulation. The controller composed of an incremental proportional-integral-derivative control and a discrete sliding mode control with exponential reaching law was designed based on the dynamic models. Experiments were performed to investigate the control performance during micro grasping process, and the results show that the developed compliant microgripper exhibits good performance, and fast and robust grasping operations can be realized using the developed microgripper and controller.

Design and Control of a Compliant Microgripper With a Large Amplification Ratio for High-Speed Micro Manipulation

A review of recent studies on non-resonant piezoelectric actuators

A piezoelectric-driven actuator based on the lateral motion principle is proposed in this paper, it can achieve large-stroke linear motion with high resolution. One parallelogram-type flexure hinge mechanism and one piezoelectric stack are used to generate the lateral motion. The mechanical structure and working principle are discussed. A prototype was fabricated and a series of experiments were carried out to investigate its working performance. The results indicate that the maximum moving speed is about 14.25 mm s−1, and the maximum output force is 3.43 N, the minimum stepping displacement is about 0.04 μm. The experiments confirm that the lateral motion can be used to design piezoelectric actuators with a large moving stroke and high accuracy with a compact size. This actuator can be used in fast tool servo systems for ultra-precision machining, precision motors for aerospace, focusing systems for optics, and so on.

https://iopscience.iop.org/article/10.1088/0964-1726/24/6/065007/pdf

Design and experimental performances of a piezoelectric linear actuator by means of lateral motion

This paper presents a novel driving principle by means of the parasitic motion of the microgripper. Actuators based on this principle can realize the large displacement range and high speed easily. Also the structure can be simple. A parasitic motion principle linear actuator mainly consisting of two piezoelectric stacks, two microgrippers and a mover was designed. Experimental results indicate that at a low driving frequency of 5 Hz, large velocity over 40 μm/s is obtained with the driving voltage of 100 V. Backward motion was observed and analyzed. Experimental results verify the feasibility of the new principle and it can be used to design new linear or rotary actuators.

A novel driving principle by means of the parasitic motion of the microgripper and its preliminary application in the design of the linear actuator.

Nanoindentation technology is developing toward the in situ test which requires miniaturization of indentation instruments. This paper presents a miniaturization nanoindentation device based on the modular idea. It mainly consists of macro-adjusting mechanism, x-y precise positioning platform, z axis precise driving unit, and the load-depth measuring unit. The device can be assembled with different forms and has minimum dimensions of 200 mm × 135 mm × 200 mm. The load resolution is about 0.1 mN and the displacement resolution is about 10 nm. A new calibration method named the reference-mapping method is proposed to calibrate the developed device. Output performance tests and indentation experiments indicate the feasibility of the developed device and calibration method. This paper gives an example that combining piezoelectric actuators with flexure hinge to realize nanoindentation tests. Integrating a smaller displacement sensor, a more compact nanoindentation device can be designed in the future.

Experimental research on a modular miniaturization nanoindentation device.

Research on material removal mechanism is meaningful for precision and ultra-precision manufacturing. In this paper, a novel scratch device was proposed by integrating the parasitic motion principle linear actuator. The device has a compact structure and it can be installed on the stage of the scanning electron microscope (SEM) to carry out in situ scratch testing. Effect of residual chips on the material removal process of the bulk metallic glass (BMG) was studied by in situ scratch testing inside the SEM. The whole removal process of the BMG during the scratch was captured in real time. Formation and growth of lamellar chips on the rake face of the Cube-Corner indenter were observed dynamically. Experimental results indicate that when lots of chips are accumulated on the rake face of the indenter and obstruct forward flow of materials, materials will flow laterally and downward to find new location and direction for formation of new chips. Due to similar material removal processes, in situ scratch testing is potential to be a powerful research tool for studying material removal mechanism of single point diamond turning, single grit grinding, mechanical polishing and grating fabrication.

/pdf/effect-of-residual-chips-on-the-material-removal-process-of-gwi1ajl3qf.pdf

Effect of residual chips on the material removal process of the bulk metallic glass studied by in situ scratch testing inside the scanning electron microscope

In situ nanomechanical tests provide a unique insight into mechanical behaviors of materials, such as fracture onset and crack propagation, shear band formation and so on. This paper presents a novel in situ nanoindentation device with dimensions of 103mm×74mm×60mm. Integrating the stepper motor, the piezoelectric actuator and the flexure hinge, the device can realize coarse adjustment of the specimen and precision loading and unloading of the indenter automatically. A novel indenter holder was designed to guarantee that the indenter penetrates into and withdraws from the specimen surface vertically. Closed-loop control of the indentation process was established to solve the problem of nonlinearity of the piezoelectric actuator and to enrich the loading modes. The in situ indentation test of Indium Phosphide (InP) inside the scanning electron microscope (SEM) was carried out and the experimental result indicates the feasibility of the developed device.

A novel and compact nanoindentation device for in situ nanoindentation tests inside the scanning electron microscope

Randomness and discreteness for appearance of pop-out of the single crystal silicon with a (100) orientation were studied by a self-made indentation device. For a given maximum penetration load, the load Ppo for appearance of pop-out fluctuates in a relatively large range, which makes it hard to study the effect of the loading/unloading rate on the load Ppo. Experimental results with different maximum penetration loads indicate that the critical penetration load for appearance of pop-out is in the range of 15 mN~20 mN for the current used single crystal silicon. For a given maximum penetration load, the load Ppo for appearance of pop-out seems random and discrete, but in the point of statistics, it has an obviously increasing trend with increase of the maximum penetration load and also the fraction Ppo/Pmax approximately keeps in the range of 0.2~0.5 for different maximum penetration loads changing from 15 mN to 150 mN.

/pdf/randomness-and-statistical-laws-of-indentation-induced-pop-4s98g4kquk.pdf

Shunguang Wan

Papers

A novel driving principle by means of the parasitic motion of the microgripper and its preliminary application in the design of the linear actuator.

Experimental research on a modular miniaturization nanoindentation device.

Effect of residual chips on the material removal process of the bulk metallic glass studied by in situ scratch testing inside the scanning electron microscope

A novel and compact nanoindentation device for in situ nanoindentation tests inside the scanning electron microscope

Randomness and Statistical Laws of Indentation-Induced Pop-Out in Single Crystal Silicon