Hexagonal Electrohydraulic Robotic Modules: Shaping the Future of Versatile Robotics

The Max Planck Institute for Intelligent Systems (MPI-IS) has unveiled a groundbreaking technology that promises to revolutionize robotics: hexagonal electrohydraulic robotic modules, known as HEXEL modules. Developed by researchers in MPI-IS’s Robotic Materials Department under the leadership of Christoph Keplinger, these modules represent a new frontier in robotic design and functionality, particularly in resource-limited environments like space exploration and rescue missions.

Introducing HEXEL Modules

Crafted with innovation at their core, HEXEL modules are hexagon-shaped components that can snap together much like LEGO pieces. This modularity allows for rapid assembly and reconfiguration of robots to suit a variety of tasks and environments. The ability to reshape these robotic units introduces a sustainable approach to robotics, enabling diverse applications without the need for multiple specialized machines.

Each module features a robust exoskeleton composed of six lightweight, rigid glass fiber plates. The inner joints are powered by Hydraulically Amplified Self-healing Electrostatic (HASEL) artificial muscles. When electricity is applied, these muscles activate, causing the module to change shape from long and narrow to wide and flat. This clever combination of soft and rigid components empowers HEXEL modules to achieve both high strokes and speeds.

“Combining soft and rigid components in this way enables high strokes and high speeds. By connecting several modules, we can create new robot geometries and repurpose them for changing needs,” explains Ellen Rumley, a Ph.D. student and visiting researcher from the University of Colorado Boulder.

Key Features and Functionality

One of the most impressive attributes of HEXEL modules is the magnetic connections embedded along their surfaces. These magnets facilitate quick and secure mechanical and electrical connections between neighboring modules, allowing users to configure robots with an array of shapes and capabilities.

The actuation performance is equally remarkable. HEXEL modules can achieve a peak contractile strain rate of 4,618% per second and a contraction of 49%. Such performance metrics denote their ability to handle dynamic tasks and respond swiftly to changing conditions.

In a demonstration video, the research team showcases the versatility of HEXEL modules:

• Crawling Through Narrow Gaps: A group of modules rearranged to navigate tight spaces, highlighting their potential in search and rescue operations.
• Leaping into the Air: A single module actuating rapidly enough to propel itself off the ground, demonstrating high-speed capabilities.
• Rolling Motion: Multiple modules connected into a structure that rolls, illustrating how different configurations can produce diverse movements.

Real-World Applications

HEXEL modules are poised to address pressing needs in various scenarios:

• Resource-Limited Environments: In settings like space missions or disaster zones, where resources are constrained, the reconfigurable nature of HEXEL modules allows for versatile applications without the need for multiple specialized robots.
• Adaptability in Rescue Missions: Their ability to be quickly reconfigured makes them ideal for rescue operations, where tasks can change rapidly, and flexibility is paramount.
• Sustainable Design: By using the same components to build different robots, there is a reduction in material usage and cost, aligning with sustainable practices.

“It makes a lot of sense to develop robots with reconfigurable capabilities. Instead of buying five different robots for five different purposes, we can build many different robots by using the same components,” emphasizes Zachary Yoder, a Ph.D. student at MPI-IS.

Future Potential

While the immediate focus is on applications in space exploration and rescue missions, the future trajectories for HEXEL modules are promising across various domains:

• Healthcare: Adaptable robots could assist in patient care, rehabilitation, or surgical procedures.
• Industrial Automation: Flexible robotic systems can optimize manufacturing processes by adapting to different tasks on the fly.
• Environmental Monitoring: Robots that can reconfigure themselves may better navigate diverse terrains for data collection.

Ongoing research may lead to even more sophisticated robotic systems, including humanoid integrations. The ability of HEXEL modules to operate untethered is also significant; innovations like the Snap Supply module can power a single HEXEL for up to 40 minutes, further streamlining operations.

The Team Behind the Innovation

The development of HEXEL modules is the result of a collaborative effort by a dedicated team of researchers:

• Christoph Keplinger: Managing Director of the Robotic Materials Department at MPI-IS.
• Ellen H. Rumley: Ph.D. student and visiting researcher from the University of Colorado Boulder.
• Zachary Yoder: Ph.D. student at MPI-IS.
• Ingemar Schmidt: Ph.D. student at MPI-IS.
• Philipp Rothemund: Tenure-track professor at the University of Stuttgart.

Their collective expertise spans soft robotics, artificial muscles, and innovative robotic design, contributing significantly to the advancement of intelligent systems.

Conclusion

By leveraging the innovative design and flexible functionality of hexagonal electrohydraulic robotic modules, robotics is poised to enter a new era characterized by efficiency, sustainability, and versatility. The HEXEL modules stand as a testament to the spirit of innovation at MPI-IS, marrying cutting-edge technology with practical applications for the future.

As researchers continue to refine these technologies, the possibilities become significantly vast, promising to transform industries and enhance capabilities in challenging environments. The reconfigurable nature of HEXEL modules not only offers immediate solutions but also sets the stage for future advancements in robotics across multiple sectors.

Reference: https://is.mpg.de/news/hexagonal-electrohydraulic-modules-shape-shift-into-versatile-robots

Yoder, Z., Rumley, E. H., Schmidt, I., Rothemund, P., & Keplinger, C. (2024). Hexagonal electrohydraulic modules for rapidly reconfigurable high-speed robots. Science Robotics. DOI: 10.1126/scirobotics.adl3546