A team of researchers from the University of Maryland 3D printed a flexible robotic hand agile enough to play Super Mario Bros. from Nintendo and win.

The feat, highlighted on the cover of the last issue of Scientists progress, demonstrates a promising innovation in the field of “soft robotics”, which creates new types of flexible and inflatable robots powered by water or air rather than electricity. The safety and adaptability inherent in soft robots has sparked interest in their use for applications such as prosthetics and biomedical devices. Unfortunately, controlling the fluids that make these soft robots bend and move has been particularly difficult.

But in a key breakthrough, the team led by Ryan D. Sochol, assistant professor of mechanical engineering, developed the ability to 3D print fully assembled flexible robots with “an integrated fluidics system.” circuits ”in one step.

“Previously, each finger of a flexible robotic hand typically needed its own line of control, which can limit portability and usefulness,” said the post’s co-first author Joshua Hubbard ’19. Now pursuing a doctorate. in Chemical and Biomolecular Engineering at the University of California at Berkeley, he carried out the research while he was an undergraduate researcher at the University of Sochol. Advanced Bioinspired Manufacturing Laboratory (BAM) at UMD. “But by 3D printing the flexible robotic hand with our built-in ‘fluidic transistors’, it can play Nintendo on the basis of a single pressure input.”

As a demonstration, the team designed an integrated fluidic circuit that allowed the hand to operate in response to the force of a single control input. For example, applying low pressure, only the first finger pressed the Nintendo controller to make Mario walk, while high pressure caused the character to jump. Guided by a defined schedule that autonomously alternated between off, low, medium and high pressures, the robotic hand was able to complete the first level of Super Mario Bros. in less than 90 seconds.

“Recently, several groups have tried to exploit fluidic circuits to improve the autonomy of soft robots,” said co-first author of the study, Ruben Acevedo Ph.D. ’21. “But the methods of building and integrating these fluidic circuits with the robots can take days to weeks, with a high degree of manual labor and technical skill.”

To overcome these obstacles, the team turned to “PolyJet 3D printing,” which is like using a color printer, but with many layers of multi-material “inks” stacked on top of each other.

“Within a day and with minimal work, researchers can now go from pressing ‘start’ on a 3D printer to having complete flexible robots, including all flexible actuators, fluid circuit and body characteristics, ready to use. Said study co-author Kristen Edwards ’20, who is currently studying for a doctorate. in Mechanical Engineering and Machine Learning at the Massachusetts Institute of Technology.

The choice to validate their strategy by beating the first level of Super Mario Bros. in real time was motivated as much by science as by pleasure. Because the timing and composition of the video game level are established, and a single mistake can lead to an immediate error game over, playing Mario has provided a new way to assess the performance of flexible robots that are particularly difficult in a way that is not usually addressed in the field.

In addition to Nintendo’s robotic hand, the Sochol team also reported some turtle-inspired soft robots in their article, and all of the team’s soft robots were printed at UMD. Terrapin works 3D printing center.

The team’s strategy is “open source,” with the document accessible to anyone, and it includes a link in the additional documents to a GitHub with all of the electronic design files of their work.

“(A) anyone can easily download, edit on demand, and 3D print – whether with their own printer or through a print service like us – all the software robots and fluidics of our work. “Sochol said. “We hope that this open source 3D printing strategy will expand the accessibility, delivery, reproducibility, and adoption of flexible robots with integrated fluidics and, in turn, accelerate advancements in the field.”

The team is exploring the use of their technique for biomedical applications, including rehabilitation devices, surgical tools and customizable prostheses. Sochol is a faculty member of the Fischell Department of Bioengineering and a member of both the Maryland Robotics Center and the Robert E. Fischell Institute for Biomedical Devices, providing a fertile environment to continue advancing the team’s strategy to address pressing biomedical challenges.