Engineers from the Swiss ETH Zurich and the Max Planck Institute for Intelligent Systems have developed an innovative muscle actuator that mimics the work of human muscles. Unlike traditional robots that use electric motors, the new system is powered by electrohydraulic “muscles”. HASEL actuators consist of oil-filled plastic bags with electrically conductive electrodes. When voltage is applied to them, they are attracted, compressing the bag and creating a movement similar to the contraction of a muscle. Pairs of such actuators attached to the skeleton replicate the natural movements of flexion and extension of the limbs. Unlike electric motors that depend on sensors to determine the position of the leg, the artificial muscle adapts to its environment with just 2 inputs - for flexion and extension of the joint. Although at the current stage the robotic leg is limited in free movement, the researchers see great potential for this technology. According to the authors of the project, in the future, such “muscular” limbs may find application in rescue robotics for traveling through complex landscapes.