An interdisciplinary group of scientists and engineers from the University of Minnesota Twin Cities has created a first-of-its-kind extrusion method that permits the growth of synthetic materials. Researchers will be able to make better soft robots that can move through difficult terrain, hard-to-reach places, and maybe even parts of the human body.
The study is published in the Proceedings of the National Academy of Sciences (PNAS).
Chris Ellison, a professor in the Department of Chemical Engineering and Materials Science at the University of Minnesota Twin Cities and one of the paper’s lead authors, said, “This is the first time these concepts have been fundamentally demonstrated.” “The competitiveness of our nation and the introduction of new products to the public depend heavily on the development of new manufacturing techniques. The use of robots in hazardous and remote environments is increasing, and these are the kinds of places where this work could have an impact. ”
In the emerging field of “soft robotics,” flexible, soft materials are used to create robots rather than rigid ones. Soft-growing robots have the ability to generate new material and “grow” while moving. These machines might be used for tasks that humans can’t perform in remote locations, like installing or inspecting tubes below ground or navigating inside the human body for biomedical uses.
Similar to how a 3D printer is fed solid filament to produce its shaped product, current soft-growing robots drag a trail of solid material behind them and can use heat and/or pressure to transform that material into a more durable structure. However, it becomes more challenging to pull the solid material trail around bends and turns, making it challenging for the robots to move through terrain with obstacles or winding paths.
The University of Minnesota team was able to solve this issue by creating a new method of extrusion, a procedure where material is forced through an opening to produce a specific shape. This new method makes it possible for the robot to make its synthetic material from a liquid instead of a solid.
Matthew Hausladen, the paper’s first author and a Ph.D. candidate in the University of Minnesota Twin Cities Department of Chemical Engineering and Materials Science, said, “We were really inspired by how plants and fungi grow.” We translated that into an engineering system, taking the idea that plants and fungi add material at the end of their bodies, either at their root tips or at their new shoots. ”
Water is used by plants to transport the building blocks that eventually solidify into roots as they spread outward. Using a process called photopolymerization, which turns liquid monomers into solid materials using light, the researchers were able to replicate this process with synthetic materials. With the aid of this innovation, the soft robot will be able to move through tight spaces and around curves without having to drag anything heavy behind it.
There are uses for this new procedure in manufacturing as well. Because the researchers’ method only uses liquid and light, it might not be necessary to use heat, pressure, and expensive machinery to make and shape materials.
The involvement of material scientists, chemical engineers, and robotic engineers is “a very important part of this project,” according to Ellison. “We really brought something special to this project by combining all of our various areas of expertise, and I’m sure that none of us could have completed it on our own. This is a fantastic illustration of how scientific collaboration allows researchers to tackle extremely challenging fundamental issues while also having an impact on technology. ”
The National Science Foundation provided funding for the study.
Researchers Boran Zhao (postdoctoral researcher) and Lorraine Francis (College of Science and Engineering Distinguished Professor) of the University of Minnesota’s Department of Chemical Engineering and Materials Science, as well as Tim Kowalewski (associate professor) and Matthew Kubala (graduate student) of the University of Minnesota’s Department of Mechanical Engineering, were also on the research team.
