Scientists at the Max-Planck-Institute for Intelligent Systems (MPI-IS) have developed a new type of modular robot system that can be rapidly reconfigured for various tasks. The research, titled "Hexagonal electrohydraulic modules for rapidly reconfigurable high-speed robots," is published in Science Robotics.
Led by Christoph Keplinger, the team from the Robotic Materials Department at MPI-IS has created hexagon-shaped robotic components, dubbed HEXEL modules. These modules can be snapped together in a LEGO-like fashion to form robots with diverse shapes and capabilities.
Each HEXEL module consists of six lightweight rigid plates made from glass fibre, forming an exoskeleton. The inner joints of these hexagons are powered by hydraulically amplified self-healing electrostatic (HASEL) artificial muscles. When a high voltage is applied, these muscles activate, causing the hexagon to change shape from long and narrow to wide and flat.
Ellen Rumley, a visiting researcher from the University of Colorado Boulder, and co-first author of the study, explains, "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."
The versatility of the HEXEL modules is demonstrated in a video showcasing various behaviours. A group of modules can crawl through narrow gaps, while a single module can actuate so rapidly that it leaps into the air. When multiple modules are connected, they can form larger structures capable of different motions depending on their configuration. For instance, the team created a robot that can roll rapidly by combining several modules.
Zachary Yoder, joint co-first author, highlights the sustainability aspect of this design: "Instead of buying five different robots for five different purposes, we can build many different robots by using the same components." This approach could be particularly beneficial in resource-limited environments, such as space exploration or rescue missions.
The HEXEL modules feature magnets embedded along their outer edges, allowing for quick mechanical and electrical connections between modules. This design enables rapid reconfiguration of the robots to adapt to changing tasks or environments.