Researchers at the Max Planck Institute for Intelligent Systems in Germany and the University of Colorado Boulder in the United States have developed new lightweight robots using the principles of spider joints.
A study calledSpider-inspired electro-hydraulic actuators for fast, soft-acting connections“Published in Advanced Science.
Spiders often serve as inspiration in the field of robotics, especially when they move their limbs through hydraulic drive mechanisms when hunting for prey that scientists try to implement in robots.
Using these principles, the research team was able to drive articulated robots without large parts and connectors to help avoid pressing them and increase portability and speed.
Thanks to the light simple structures used in the construction, the robot can jump 10 times its height.
The researchers relied on Spider-inspired soft-guided electro-hydraulic joints or SES joints to achieve high performance in robots. The joints can be configured in many ways, including outside the arachno bot.
The research paper describes a two-way joint, a multi-segment artificial limb, and a three-finger gripper that can be used to grip and pick objects. All different creations have similar characteristics. They are lightweight, simple and highly efficient, which means they are useful for robotic systems that require fast movement and interact with different environments.
SES joints were based HASEL a technique the team has previously invented to build artificial muscle. The SES joints mimic an exoskeleton mechanism with both rigid and softer elements, in the same way that a spider stretches its legs through hydraulic forces.
Development of spider-inspired robots
The researchers first created a flexible bag made of thin plastic films filled with a liquid dielectric. The electrodes were then placed on both sides of the bag, and the pockets acted as actuators, producing hydraulic force through electrostatic forces.
The bag is connected to a rotating joint, and when a high voltage is applied between the electrodes, the liquid dielectric moves inside the bag and the joint bends. SES joints can rotate up to 70 degrees, resulting in high torques, and can easily return to the starting position.
Christoph Keplinger is Director of the Robotics Department at the Max Planck Institute for Intelligence Systems.
“SES connections are very simple and light because the robot is not pressed from peripherals,” Keplinger says. “Many soft robot applications require versatile actuators. These spider-inspired joints allow for high functionality and low power consumption, are easy and inexpensive to manufacture – the plastics we use are for food packaging – and their production is easily scalable. These are all critical to the design of robots that can move in many different ways and manipulate different objects without breaking them. “
The researchers demonstrated the versatility of SES joints with a three-finger gripper. If the gripper relied on a muscle-like structure, it would be prevented from trying to grip the object. But when SES joints are hinges, much less space is needed.
Nicholas Kellaris is the first author of the paper.
“Research stands out in that we can use a wide variety of materials, even plastic, that is used to make chip bags to create the bags,” Kellaris says. “In this way, we can implement SES in a wide variety of geometries with specially tuned operating characteristics.”
Phillip Rothemund is the co-author of the publication.
“The ultimate goal of our study was not to make a spider robot,” Rothemund adds. “We wanted to develop a state-of-the-art, active connection that you can put into any robot.”