In context
In early 2023, precision micromanipulation in biomedical and manufacturing applications demanded micro-motion mechanisms with both large stroke and high accuracy. Existing compliant mechanisms often traded off workspace against precision, limiting their practical use.
What was reported
Researchers at Yanshan University proposed a novel 3-PRC compliant parallel micro-motion mechanism that integrates large-stroke flexible plate springs with high-precision notch-type flexure hinges. The design achieves approximate full decoupling for three translational degrees of freedom.
Structural optimizations included a bridge-type displacement amplifier to magnify piezoelectric actuator output and avoid stress stiffening, a dual-R flexure hinge to improve strength, inverted branch chains to counteract gravity effects, and series-connected compensating flexures to cancel parasitic motions.
Kinematic analysis using the vector method yielded input-output relationships and theoretical coupling errors. Finite element simulations evaluated amplification ratio and coupling errors, followed by prototype testing. The mechanism achieved a workspace of 188.75 μm × 186.0 μm × 185.12 μm with a maximum coupling error of 5.6%, meeting the target of over 100 μm stroke and micrometer-level precision.
Why it mattered
This work addressed the long-standing conflict between high precision and large stroke in compliant mechanisms, offering a compact, decoupled solution that could enhance performance in micromanipulation, laser alignment, and other precision automation applications.
"The results show that the parallel micro-motion mechanism can achieve three-dimensional movement with the workspace of 188.75 μm×186.0 μm×185.12 μm and the maximum coupling error of 5.6%."
Source: 《机器人》期刊 (robot.sia.cn) · Published 2023-03-11 · “一种新型大行程高精度并联微动机构的研究与分析”