Abstract
Precise and stable operations in micromanipulation and microassembly require a high-performance microgripper. To improve the predominant static and dynamic characteristics, a novel piezoelectric-actuated compliant microgripper is designed, analyzed, and tested in this paper. The microgripper realizes a large gripping stroke by integrating a compliant bridge mechanism, an L-shaped mechanism, and a levered parallelogram mechanism. Optimization technology based on response surface analysis is applied to demonstrate the influence of structural parameters on the microgripper performance. Simulation results of finite element analysis reveal the superior performance of the designed microgripper in terms of gripping displacement, mechanism stiffness, equivalent stress, and natural frequency. A gripper prototype has been fabricated, and experimental studies have been conducted to test the microgripper’s physical properties. Experimental results show that the microgripper can grasp micro-objects with a maximum jaw motion stroke of 312.8 μm, natural frequency of 786 Hz, motion resolution of ±0.6 μm, and force resolution of ±1.69 mN. The gripping tests of an optical fiber with a diameter of 200 μm and a metal sheet with a thickness of 100 μm have been performed to demonstrate its gripping capability with position and force control.
Highlights
Micro/nano-manipulation robots are a significant application of robotic automation technology at the micro/nano meter scale
The error data obtained from the experiment meet the normal distribution condition with 2σ of 2.54 μm, i.e., 95% confidence interval for the error locating in ±2.54 μm
Experimental Results of Gripping Test To demonstrate the gripping capability of the designed gripper, the gripping experiment was carried out using an optical fiber with a diameter of 200 μm and a metal sheet with a thickness of 100 μm
Summary
Micro/nano-manipulation robots are a significant application of robotic automation technology at the micro/nano meter scale. As PEA’s output displacement is extremely short (about 0.1% of PEA length), a popular design goal of the piezoelectric-actuated microgripper is to achieve a large gripping range. To obtain a large gripping stroke, researchers have applied different types of compliant amplification mechanisms to design micromanipulators, such as lever mechanisms and bridge mechanisms [7–9]. A practical microgripper demands a large gripping stroke and a high natural frequency at the same time. The lever, bridge, and parallelogram mechanisms were integrated in a symmetrical microgripper, which obtained a natural frequency of 1044 Hz [17]. It is necessary to design a piezoelectric-actuated microgripper with a large gripping range and high natural frequency to satisfy the increasing demands of applications. The gripping stroke, gripping force, natural frequency, tracking ability, and motion resolution of the microgripper were tested by open-loop and closedloop experiments.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
