Variable stiffness muscle-assist device using electrostatic static friction and control method thereof

Muscle-assistive device with variable stiffness using electrostatic static friction

This technology relates to a variable-stiffness muscle-assistive device and its control method using electrostatic static friction, which adjusts interlayer friction through voltage application to vary stiffness in real time.

Existing layer jamming actuators were difficult to apply in scenarios requiring high bending or torsional stiffness due to their structural characteristics, and they faced limitations in response speed and stiffness range.

By applying voltage to a multi-layered stack to generate electrostatic static friction and controlling stiffness accordingly, this technology improves both effectiveness and response speed in wearable robots and exoskeleton suits.

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Key Features:

• A multi-layered stack worn on the human skeleton and joints to assist muscle strength, featuring overlapping sections at the joint connections.
• Layers are coupled to allow relative sliding and rotation, with each layer comprising an electrode layer and a dielectric layer.
• Electrode and dielectric layers configured to induce electrostatic force by applying an electric field between the layers in relative motion.
• A configuration that varies stiffness by using electrostatic force to induce static friction, thereby preventing relative motion between the layers.

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This invention was developed with support from the Ministry of Trade, Industry and Energy’s project for a human-augmentation hybrid robot suit capable of a safe 7-second 100m dash and 12-hour comfortable wear, and the Ministry of Education’s project for high-speed hand motion control using a variable-stiffness exo-glove.