Flexure mechanisms for high precision applications

Flexure mechanisms are flexible structures that are designed to deliver desired motions via elastic deformations. Due to their unique actuation, these structures can effectively eliminate backlash and dry friction, allowing them to achieve highly repeatable motions. As a result, flexure mechanisms have become the ideal candidates for constructing high precision robotic systems, and they have been deployed across a wide range of applications pertaining to biomedical research, microscopy technologies and various industrial manufacturing processes.

From the design perspective, there are two important performance indexes for the flexure mechanisms: 1. their stiffness and 2. their dynamic properties. As it is conflicting to optimize both of these indexes concurrently, it is currently still a great challenge to design flexure mechanisms with optimal performances. To address this critical issue, we have previously developed a novel design methodology that can synthesize optimal flexure mechanisms. The effectiveness of this method is demonstrated via the design of an optimal X-Y-theta flexure mechanism (Video F1). While the method is promising, it is still restricted for designing flexure mechanisms with planar motions. Hence, here we will continue to explore new design methods that can be used universally across all types of flexure mechanisms.

Relevant Publications:

1. G. Z. Lum, T. J. Teo, G. L. Yang, S. H. Yeo and M. Sitti, "Structural optimization for flexure-based parallel mechanisms - towards achieving optimal dynamic and stiffness properties", Precision Engineering, vol. 42, October 2015, Pages 195-207. [link]

2. G. Z. Lum, T. J. Teo, G. L. Yang, S. H. Yeo and M. Sitti, "Integrating classical mechanism synthesis and modern topological optimization technique for stiffness-oriented design of multiple degrees-of-freedom flexure-based parallel mechanisms", Precision Engineering, vol. 39, January 2015, Pages 125-133. [link]