3D Printing Microactuators for Soft Microrobots

Abstract

Current additive manufacturing, including three-dimensional (3D) and so-called four-dimensional printing, of soft robotic devices is limited to millimeter sizes. In this study, we present additive manufacturing of soft microactuators and microrobots to fabricate even smaller structures in the micrometer domain. Using a custom-built extrusion 3D printer, microactuators are scaled down to a size of 300 • 1000 lm 2 , with minimum thickness of 20 lm. Microactuators combined with printed body and electroactive polymers to drive the actuators are fabricated from computer-aided design model of the device structure. To demonstrate the ease and versatility of 3D printing process, microactuators with varying lengths ranging from 1000 to 5000 lm are fabricated and operated. Likewise, microrobotic devices consisting of a rigid body and individually controlled free-moving arms or legs are 3D printed to explore the microfabrication of soft grippers, manipulators, or microrobots through simple additive manufacturing technique.

Electroactive Polymers Obtained by Conventional and Non-Conventional Technologies

“…AM might be especially interesting in this regard as it enables the fabrication of reduced intricate shapes with high geometric accuracy. In an attempt to test the limits of extrusion-based AM techniques, a team of researchers built a custom 3D printer that allowed the fabrication of PPy electroactive parts within the micrometer range [ 87 ].…”

Metal–Organic Frameworks in Motion

“…It is indisputable that the first wave of micro-and nanoswimmers capitalised on advances made in micro-and nanomanufacturing technologies. 33 Despite new advances in technology, it is obvious that the next generation of micro-and nanoswimmers will undoubtedly benefit from concerted contributions from the disciplines of materials science and chemistry, in specific areas that were previously disconnected to the field of micro-and nanoswimmers. 34 A recent example of this new wave is the incorporation of soft materials such as polymers, [35][36][37] gels, 38,39 or macromolecules.…”

Antagonist Concepts of Polypyrrole Actuators: Bending Hybrid Actuator and Mirrored Trilayer Linear Actuator

“…A lot of progress has been made in recent years in the field, aiming for potential applications in micro-actuators and robotics [2,3], by achieving high strains up to 34% [4] and stresses in range of 22 MPa [5]. There have been a number of different applications proposed [6] such as smart textiles [7], sensors [8], soft robotics [9], biomedical applications [10], and mechanically stimulated growth [11], and many more. The actuation principle of conductive polymers can be explained in a simplified manner by the formation of delocalized charges upon oxidation along the polymer chains, while ions (with solvent) move in to ensure charge neutrality.…”