Even after working within the 3D printing industry for as long as I have, and all of the moments of awe and amazement I have experienced over the years, I love it that stories and applications emerge that can still make me think: “Well, I never thought I’d see that!” Today, a 3D printed swimming, robotic eel has done just that. This “eel” has been developed by a team at the University of New Orleans’ (UNO) School of Naval Architecture and Marine Engineering as a, get this, “proof of concept development and motion verification of a swimming anguilliform robot.” For those of you that are now looking for a dictionary — let me save you the trouble — I just looked it up. The definition of anguilliform is, “having the shape or form of an eel.” Logical really, but not obvious. I do love coming across new words, but not sure when / if I’ll ever get the chance to use that one again. Never mind.
The team at UNO received a three year grant from the Office of Naval Research to create this anguilliform robot, which mimics the actual movement of an eel in shallow water areas such as rivers and coastlines. The specific aim of the project lies in the benefits it can bring to monitoring and data collection in water, especially in harsh and dangerous conditions. The US Navy also has an interest in the research, primarily for developing autonomous underwater vehicles (AUVs) that will be able to travel long distances into perilous environments and gather information without being detected.
The team worked with Stratasys 3D printing technology, specifically an Objet Eden platform to meet many of the challenging manufacturing requirements — or as Stratasys prefer to put it: “create an intelligent robotic eel that imitates aquatic movement so elegantly that you would think it was the real eel.” I always knew the marketing team in Israel had a great sense of humour!
In terms of the specific requirements though, it was not just about the robotic eel itself, which is challenging in its own right, but also the requirement to optimize the robot’s hydrodynamic performance taking into consideration that the final functional product would have to have cameras and heat sensors for assignments involving intelligence, surveillance and reconnaissance. This involved developing a custom-built waterproof skin that does not hinder motion in shallow waters.
The Eden 3D Printer was used with the transparent general-purpose FullCure 720 material to produce all of the eel’s 3D printed components, providing both the strength and lightweight properties required by the design. With the 3D printer’s capabilities, the team was able to produce parts faster and more efficiently than traditional practices could, and even create parts that would otherwise be impossible to make.
After designing and building the first version of the robotic eel, Taravella’s team tested various waterproof skins and the eel’s aquatic motion in the UNO’s 125-foot towing tank located in the College of Engineering Building.
The final design was the result of an iterative refinement process — greatly assisted by the capabilities of 3D printing. The team was able to churn out numerous design changes, gain immediate feedback throughout the development process and print out functional prototypes in just days versus the weeks and months required using traditional practices such as designing parts to be machined with a multi-axis mill or lathe.
Taravella commented: “3D printers have become a standard for research institutions, if you don’t have this type of capability, you will be left behind.”
So far, Taravella and his team have produced several realistic prototypes and based on these, have received an additional grant from the Department of Defense to continue research.
The Stratasys’ video gives more insight into how the anguilliform “swims”.