Variable stiffness mechanism using electrostatic friction

Variable Stiffness Mechanism with Fast Response and Multi-Degree of Freedom

This technology relates to a variable stiffness mechanism using electro-rheological friction, utilizing layer jamming to adjust stiffness by applying voltage to a layered stack.

Existing layer jamming drive units struggle to broadly adjust bending and torsional stiffness, and their limited resistance characteristics make them difficult to use in various postures.

By adopting a layered structure where layers are arranged to slide and rotate relative to one another, this technology achieves both fast response speeds and multi-degree of freedom, making it highly effective for stiffness control in wearable robots.

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Key Features:

• A variable stiffness device comprising a layer stack in which a plurality of layers are stacked such that their ends overlap in the vertical direction.
• A configuration where layers are coupled to allow for relative sliding and rotation, with each layer including an electrode layer and a dielectric layer.
• A configuration that induces electrostatic force and electro-rheological friction by applying an electric field between layers undergoing relative motion.
• A configuration including a plurality of first layer stacks arranged to be spaced apart in the vertical direction and a second layer arranged at a specific interval.

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This invention was developed with support from the Ministry of Trade, Industry and Energy for the development of a human-augmentation hybrid robot suit capable of safe 100m sprints in 7 seconds and comfortable 12-hour wear.