Electrohydraulic "Arachno-Bot" Showcases a New, Spider-Inspired Articulation for Lightweight Robots
Based on the hydraulics of spider legs, these lightweight actuators let robots jump 10 times their height — or grip delicate objects.
Roboticists at the Max Planck Institute for Intelligent Systems and the University of Colorado Boulder have come up with a novel articulation for lightweight robots — based on the way spiders' legs work.
Spiders hydraulic-powered limbs have long been of interest to roboticists, but the Spider-inspired Electrohydraulic Soft-actuated joints — SES joints — are nothing short of impressive. Designed to be as light and streamlined as possible, the SES joints deliver performance that allow robots to jump 10 times their own height — or pick up delicate objects in a three-fingered gripper at the end.
"The SES joints are very simple and light, as there are no peripheral components which weigh down the robot," says Christoph Keplinger, director of the Robotic Materials Department at the Max Planck Institute for Intelligence Systems. "Many applications for soft robots require versatile actuators."
"These spider-inspired joints allow for high functionality and consume only little power, they are easy and cheap to make - the plastics we are using are for food packaging — and their production is easily scalable. These are all qualities that are critical for the design of robots, which can move in many different ways and manipulate a variety of objects without breaking them."
"The research stands out because we can use a wide variety of materials, even the plastic used to make chips bags, to create the pouches," adds first author Nicholas Kellaris. "That way we can implement SES in a wide variety of geometries with specifically tuned actuation characteristics."
The prototype SES joints are flexible pouches made of thin plastic films filled with vegetable oil. Hydraulic power is generated through electrostatic forces, and with the pouch attached to a rotary joint a high voltage makes the joint flex. The team found the prototypes able to rotate up to 70 degrees, cause high torques, yet easily return to their stating positions.
"The ultimate goal of our research was not to make a spider robot," second author Philipp Rothemund clarifies. "We wanted to develop a state-of-the-art, active joint that you can put in any type of robot."
The team's work has been published under open-access terms in the journal Advanced Science.