The Secret to Smooth Robotic Movement

In this video, researchers unveil a breakthrough in robotic motion using stretchable electrohydraulic artificial muscles. Inspired by the elegant, full-range movements of animal joints, the team tackles a key limitation in current soft actuators—lack of stretchability. Traditional electrohydraulic actuators (Hazels) can contract but not extend, hindering their ability to mimic natural muscle behavior, especially in antagonistic pairs like biceps and triceps.

To overcome this, the team introduced stretchable electrostatic clutches, creating a muscle-clutch unit that can both contract and elongate. These new units operate in four controllable states, enabling synchronized, lifelike joint motion. Experiments show that this design dramatically improves range of motion—restoring up to 50% lost with traditional slack-based solutions—and performs consistently across frequencies. This innovation brings robots one step closer to moving with the fluid grace of living beings.