Recent trends in piezoelectric actuators for precision motion and their applications: a review

Magnetic small-scale robots are devices of great potential for the biomedical field because of the several benefits of this method of actuation. Recent work on the development of these devices has seen tremendous innovation and refinement toward ​improved performance for potential clinical applications. This review briefly details recent advancements in small-scale robots used for biomedical applications, covering their design, fabrication, applications, and demonstration of ability, and identifies the gap in studies and the difficulties that have persisted in the optimization of the use of these devices. In addition, alternative biomedical applications are also suggested for some of the technologies that show potential for other functions. This study concludes that although the field of small-scale robot research is highly innovative ​there is need for more concerted efforts to improve functionality and reliability of these devices particularly in clinical applications. Finally, further suggestions are made toward ​the achievement of commercialization for these devices.

Micro/nanoscale magnetic robots for biomedical applications.

Dynamic performance of piezoelectric energy harvesters with a multifunctional nanocomposite substrate

Micro/nano manipulation for both mechanical and biological structures is currently a popular research field. To protect small-scale structures and acquire their mechanical properties, a micro-scale force sensor is needed. This paper focuses on reviewing the research on non-contact micro-force sensor parts that can be integrated in this manipulation system. The content involves the structure, working principle, resolution and sensitivity of different force sensor parts, including electrical and optical force sensors. The electrical force sensors include piezoresistive, piezoelectric, capacitive, electrothermal and strain gauge-based types; while the optical force sensors focus on but are not restricted to the optical fiber-based force sensors and the vision-based sensing systems. All of these sensors are analysed and compared. Electrical force sensors are currently widely used but are restricted by the sensing properties and size; optical force sensors have high sensitivity, small structure and anti-electromagnetic-interference properties, but they are hardly applied in micro/nano manipulation systems for force measurement. As a result, optical force sensors may become the new generation of sensors that can be integrated with micro/nano manipulation systems.

Recent advances in non-contact force sensors used for micro/nano manipulation

The piezoelectric-actuated compliant microgripper (PEACM) plays an essential role in the application fields such as biomedical engineering, microelectronics, and optical engineering. As compared with other categories of grippers, PEACM exhibits the advantages of high accuracy of displacement, large power to weight ratio, low energy consumption, and fast response speed. This paper reviews the recent advances on performance indices, classification, structural composition, optimization and modeling method, and control of PEACM. First, the gripper's performance indices and classifications are elaborated, which is beneficial to determine the design goal. Then, the compliant mechanisms adopted in the microgripper design are discussed, including the flexible hinge, displacement amplifier, and guiding mechanism. In addition, the optimization and modeling methods of the microgripper are presented. Popular types of position/force sensors and different displacement/force control strategies employed in the microgripper are surveyed. Moreover, the prospect on future development trend of the PEACM is discussed. The paper provides the reader with an overview of the recent advances on PEACM design and also a guideline on further development of the microgripper.

Recent design and development of piezoelectric-actuated compliant microgrippers: A review

This paper presents the development of a monolithic two degrees of freedom (2 DOF), piezoelectric actuated microgripper for the manipulation of micro-objects. Micromanipulation and microassembly are the major subjects of interest in recent times and are becoming increasingly important in many domains. An effort is being made to develop a novel 2 DOF microgripper, each jaw being able to move independently to grasp and rotate objects of micro sizes. Microgripper is developed based on the compliant mechanism. The designed 2 DOF compliant microgripper is modeled using FEM and PRBM approach further validated experimentally. The microgripper is actuated using APA 120-S piezoelectric stack actuators. The displacement of the microgripper and the gripping force is measured by image processing technique using LabVIEW tools. The microgripper is subjected to various tests to measure the displacement amplification ratio and micromanipulation experiments. Wire of various sizes are used to test the grasping and rotating sequence of the microgripper. The theoretical, simulation and experimental results reveal the good performance of the microgripper.

Karanth P. Navin

Papers

Recent trends in piezoelectric actuators for precision motion and their applications: a review

Design, fabrication and testing of a 2 DOF compliant flexural microgripper