A Piezoelectrically-Actuated Mesoscale Compliant Parallel Robot via Additive Manufacture

Abstract

Micro-positioning and pick-and-place applications at the millimeter scale are driving the development of smaller robots necessitating the use of alternative methods for design and manufacture. Additive manufacturing can enable significant cost and time savings in the fabrication of robots while having a low barrier to entry. Specifically, multimaterial 3D printing naturally lends itself to the creation of monolithic mechanisms by removing the requirement for manual assembly, in particular, when compliant joints can replace the rigid joints that are traditionally used. The lack of an assembly requirement naturally opens up the possibility of reducing the size scale of these mechanisms. In this work, the design, fabrication, and characterization of an additively manufactured mesoscale compliant parallel robot actuated by piezoelectric bimorphs through a compliant transmission mechanism is presented. The transmission mechanism is required to convert and amplify the small but rapid linear displacements of piezoelectric actuators into the large rotational motion that is required to create a large workspace for the compliant parallel robot. The developed planar parallel robot has a workspace with maximum planar extents of 14.36 mm by 8.66 mm, with a total area of 65.6 mm<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup>. Three different trajectories are tracked at frequencies of up to 10 Hz, demonstrating the robot's capability to rapidly follow trajectories in its workspace.