Review Article: Inventory of platforms towards the design of a statically balanced six degrees of freedom compliant precision stage

Abstract

Abstract. For many applications in precision engineering, a six degrees of freedom (DoF) compliant stage (CS) with zero stiffness is desirable, to deal with problems like backlash, friction, lubrication, and at the same time, reduce the actuation force. To this end, the compliant stage (also known as compliant mechanism) can be statically balanced with a stiffness compensation mechanism, to compensate the energy stored in the compliant parts, resulting in a statically balanced compliant stage (SBCS). Statically balanced compliant stages can be a breakthrough in precision engineering. This paper presents an inventory of platforms suitable for the design of a 6 DoF compliant stage for precision engineering. A literature review on 3-6 DoF compliant stages, static balancing strategies and statically balanced compliant mechanisms (SBCMs) has been performed. A classification from the inventory has been made and followed up by discussion. An obviously superior architecture for a 6 DoF compliant stage was not found. All the 6 DoF stages are either non-statically balanced compliant structures or statically balanced non-compliant structures. The statically balanced non-compliant structures can be transformed into compliant structures using lumped compliance, while all SBCMs had distributed compliance. A 6 DoF SBCS is a great scope for improvements in precision engineering stages.

Dynamic Analysis of a 5‐DOF Flexure‐Based Nanopositioning Stage

“…Kim [8] developed a 3-DOF out-of-plane positioning stage for optical instrument alignment. As for 6-DOF stage, parallel mechanisms with six legs were extensively applied [9,10]. Recently, the hybrid serial-parallel flexure-based mechanisms are increasingly applied due to their special merits.…”

Microactuators and Micromechanisms

“…With their distributed compliance they have a larger twist angle than hinges with concentrated compliance (e.g. notch joints) (Dunning et al 2011). To allow rotations with hinges based on leaf springs there are different possibilities as shown in Fig.…”

A statically balanced and bi-stable compliant end effector combined with a laparoscopic 2DoF robotic arm

“…Bistable compliant mechanisms have been an interesting mechanism with nonlinear stiffness behavior (Jensen et al, 2001;Hartono, 2001;Qiu et al, 2004;Li and Zhou, 2005;Sönmez, 2008; Todd et al, 2010). It has been shown that these mechanisms have the largest ratios of both compensated force and statically balanced stroke relative to the size (Dunning et al, 2011). A typical force-displacement curve of such a mechanism is shown in Fig.…”

“…However, all aforementioned works rely on preloading in a direction perpendicular to instrument actuation, and therefore protrudes outside the grasper and is difficult to be tuned for fabrication errors and improved performance. Collinear preloading has only been introduced in a few studies for other applications, such as: human skeleton (Chen and Zhang, 2011), MEMS (Tolou et al, 2010b) and precision stages (Dunning et al, 2011). This article presents a laparoscopic 2DoFs robotic arm with a statically balanced fully compliant laparoscopic grasper (namely SBCG) as the end effector.…”