In a significant breakthrough, scientists from ETH Zurich and the Max Planck Institute have developed a muscle-powered robotic leg that surpasses traditional motorized robots in agility and energy efficiency. This advancement could redefine the future of robotics.
In a groundbreaking innovation poised to redefine robotics, researchers at ETH Zurich and the Max Planck Institute for Intelligent Systems (MPI-IS) have unveiled a muscle-powered robotic leg capable of remarkable agility and adaptability. This cutting-edge development leverages artificial muscles, known as HASELs, to deliver energy-efficient movement and high jumps, akin to the mobility seen in living creatures.
Inventors have aimed to mimic the dynamic movement of humans and animals for decades. However, traditional robots, driven by motors, have struggled to achieve the same versatility.
The new robotic leg, developed under the Max Planck ETH Center for Learning Systems, takes an evolutionary leap forward by employing electro-hydraulic actuators to mimic both extensor and flexor muscle movements.
Revolutionizing Robotic Movement
Robert Katzschmann of ETH Zurich and Christoph Keplinger of MPI-IS led the ambitious project.
Co-authored by doctoral students Thomas Buchner and Toshihiko Fukushima, their study, published in Nature Communications, showcases a robotic leg that’s not just mechanically impressive but significantly more efficient than its motorized counterparts.
“[A]s soon as we apply a voltage to the electrodes, they are attracted to each other due to static electricity,” Buchner said in a news release. “Similarly, when I rub a balloon against my head, my hair sticks to the balloon due to the same static electricity.”
This novel approach positions the oil-filled plastic bags to contract and elongate, emulating natural muscle functions. Controlled via sophisticated computer codes, these actuators enhance the leg’s movements and adaptability.
Energy Efficiency at Its Core
A critical advantage of this muscle-powered design is its energy efficiency.
Unlike traditional robotic limbs, which convert a large portion of energy into heat, the new leg remains cool due to its electrostatic nature.
“It’s like the example with the balloon and the hair, where the hair stays stuck to the balloon for quite a long time,” Buchner added.
“Typically, electric motor-driven robots need heat management which requires additional heat sinks or fans for diffusing the heat to the air. Our system doesn’t require them,” added Fukushima.
Agility Across Diverse Terrains
The robotic leg’s dexterity is highlighted through its ability to explosively lift its weight and adapt to uneven terrains, closely mimicking the elastic properties of a living musculoskeletal system.
Katzschmann points out the importance of this feature.
“If we can’t bend our knees, for example, walking on an uneven surface becomes much more difficult. Just think of taking a step down from the pavement onto the road,” he said in the news release.
Traditional motorized robots depend heavily on sensors to navigate terrain. In contrast, the artificial muscle system responds dynamically to environmental stimuli with only minimal input signals required to adjust joint positions seamlessly.
“Adapting to the terrain is a key aspect,” Fukushima added.
A Leap Toward Future Applications
Although the technology has significant potential, it still faces limitations.
Currently, the leg is fixed to a rod and moves in circles. Addressing these issues could lead to fully mobile robots equipped with muscle-powered legs, paving the way for diverse applications, from rescue missions to specialized grippers for delicate tasks.
“The field of robotics is making rapid progress with advanced controls and machine learning; in contrast, there has been much less progress with robotic hardware, which is equally important,” Keplinger said. “This publication is a powerful reminder of how much potential for disruptive innovation comes from introducing new hardware concepts, like the use of artificial muscles.”
Katzschmann is optimistic about the future, envisioning a day when battery-powered robots with artificial muscles could become viable rescue devices.
“If we combine the robotic leg in a quadruped robot or a humanoid robot with two legs, maybe one day, when it is battery-powered, we can deploy it as a rescue robot,” he said.
This breakthrough in muscle-powered robotic limbs highlights a promising future in robotics, offering efficiency, adaptability and resilience that could transcend current technological limitations.