Robotic Hand Masters Nintendo Video Game

A research team at the University of Maryland 3D printed a soft robotic hand with ample agility to play and win at Nintendo’s Super Mario Bros.

The achievement, which was recently reported on by Science Advances, represents an advance in “soft robotics,” which focuses on creation of flexible, inflatable robots that run on water or air, not electricity.  Soft robots’ adaptability has lent consideration of them for applications for prosthetics and biomedical devices. However, maintaining control of the fluids that help these soft robots bend and move has presented obstacles.

An accomplishment by the team, headed up by University of Maryland assistant professor of mechanical engineering Ryan D. Sochol, was engineering a means to 3D print fully assembled soft robots with “integrated fluidic circuits” in one step. 

“Previously, each finger of a soft robotic hand would typically need its own control line, which can limit portability and usefulness,” explains co-first author Joshua Hubbard, who performed the research during his time as an undergraduate researcher in Sochol’s Bioinspired Advanced Manufacturing (BAM) Laboratory at UMD. “But by 3D printing the soft robotic hand with our integrated ‘fluidic transistors,’ it can play Nintendo based on just one pressure input.”

As a demo, the team designed an integrated fluidic circuit for the hand to operate in response to the strength of a single control pressure. For example, applying a low pressure caused only the first finger to press the Nintendo controller to make Mario walk, while a high pressure led to Mario jumping. Guided by a set program that autonomously switched between off, low, medium, and high pressures, the robotic hand was able to press the buttons on the controller to successfully complete the first level of Super Mario Bros. in less than 90 seconds.

“Recently, several groups have tried to harness fluidic circuits to enhance the autonomy of soft robots,” says recent Ph.D. graduate and co-first author of the study, Dr. Ruben Acevedo, “but the methods for building and integrating those fluidic circuits with the robots can take days to weeks, with a high degree of manual labor and technical skill.”

To overcome these barriers, 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 one another in 3D. 

“Within the span of one day and with minor labor, researchers can now go from pressing ‘start’ on a 3D printer to having complete soft robots—including all of the soft actuators, fluidic circuit elements, and body features—ready to use,” says study co-author, Kristen Edwards.

The choice to validate their strategy by beating the first level of Super Mario Bros. in real time was motivated by science just as much as it was by fun.  Because the video game’s timing and level make-up are established, and just a single mistake can lead to an immediate game over, playing Mario provided a new means for evaluating soft robot performance that is uniquely challenging in a manner not typically tackled in the field.

Part of the team strategy is to have the research be “open source,” giving the paper open access for anyone to read alongside a link in the supplementary materials to a GitHub with all electronic design files from their work.

At present, the team is exploring the use of their technique for biomedical applications including rehabilitation devices, surgical tools, and customizable prosthetics.  

Journal Reference

Joshua D. Hubbard, Ruben Acevedo, Kristen M. Edwards, Abdullah T. Alsharhan, Ziteng Wen, Jennifer Landry, Kejin Wang, Saul Schaffer, and Ryan D. Sochol, “Fully 3D Printed Soft Robots with Integrated Fluidic Circuitry,” Science Advances, 2021.

This research was supported in part by the Center for Engineering Concepts Development and U.S. NSF Award 1943356.

Sources: Press materials received from the company and additional information gleaned from the company’s website.