Engineers discover new process for synthetic material growth, enabling soft robots that grow like plants

By Newswise 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 development of synthetic materials. The new strategy will enable researchers to create better soft robots that can traverse challenging terrain, hard-to-reach locations, and maybe areas within the human body.

The study was released in the peer-reviewed, interdisciplinary, high-impact publication Proceedings of the National Academy of Sciences of the United States of America (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 primary authors, stated, "This is the first time these principles have been fundamentally proved." The competitiveness of our nation and the introduction of new products to the public depend heavily on the development of innovative manufacturing techniques. The usage of robots in hazardous and distant locations is growing, and these are the types of places where this work might have an impact.

In the growing discipline 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 devices may be employed for tasks that people can't perform in remote locations, such constructing or checking tubes below earth or travelling inside the human body for biomedical uses.

Similar to how a 3D printer is fed solid filament to make its shaped result, current soft growing robots drag a trail of solid material behind them and can utilize heat and/or pressure to turn that material into a more durable structure. However, it becomes increasingly challenging to draw the solid material track around bends and curves, making it challenging for the robots to go across terrain with obstacles or twisting roads.

By creating a novel method of extrusion, a procedure where material is forced through an aperture to produce a specified form, the University of Minnesota team was able to tackle this issue. The robot can produce its synthetic material from a liquid rather than a solid thanks to this novel method.

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 particularly impressed by how plants and fungus develop. "We converted that into an engineering system, using the premise 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 carry the building pieces that eventually solidify into roots as they spread outward. Using a method called photopolymerization, which turns liquid monomers into solid materials using light, the researchers were able to replicate this process with synthetic material. With the aid of this innovation, the soft robot will be able to go through tight spaces and around curves without having to pull anything heavy behind it.

There are uses for this innovative procedure in production as well. Operations that need heat, pressure, and expensive gear to produce and shape materials might not be necessary because the researchers' process merely requires liquid and light.

The involvement of material scientists, chemical engineers, and robotic engineers is "a really crucial aspect of this effort," according to Ellison. "We definitely offered something new to this project by combining all of our various abilities, 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 basic issues while simultaneously having an influence 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 of the University of Minnesota's Department of Mechanical Engineering, were also members of the research team (graduate student).