Electrostatic Clutches Enable High-Force Mechanical Multiplexing: Demonstrating Single-Motor Full-Actuation of a 4-DoF Hand

2025-01-14

AI Summary

Existing multi-joint robots rely on multiple motors, resulting in large system volume, high mass, and excessive energy consumption—severely limiting agility and energy efficiency. This work proposes a mechanically multiplexed actuation system based on electrostatic capstan clutches, enabling full independent joint control, synchronized actuation, and passive position holding for a commercial 4-DOF manipulator using only a single motor. Key contributions include: (i) the first electrostatically actuated capstan clutch, achieving high-torque transmission (>1.5 N·m) and zero-power self-locking; (ii) a time-division/parallel dual-mode multiplexing architecture; and (iii) an integrated self-locking leadscrew-nut output mechanism. Experimental results demonstrate superior performance over conventional approaches in torque density, ultra-low standby power (<1 mW), and scalability. The proposed paradigm advances high-integration, low-power, and robust actuation for multi-DOF robotic systems.

Technology Category

• Intelligent Robots: Manipulation
• Multiagent Systems: Mechanism Design
• Computer Vision: Multi-modal Vision

Application Category

• Responsible Web: Machine-in-the-loop, human agency and autonomy
• Systems and Infrastructure for Web, Mobile and WoT: Energy management for devices in mobile Web and WoT environments
• Economics, Online Markets and Human Computation: Incentives in network design for Web infrastructures and ecosystems

Abstract

This paper introduces a novel mechanical multiplexing system powered by electrostatic capstan clutches, enabling high-force, single-motor control of multiple degrees of freedom (DoF). The system is capable of both bidirectional single-input single-output time-division and single-input multiple-output multiplexing to actuate a commercial 4-DoF robotic hand with a single motor. Our mechanical multiplexer is also capable of powerless position holding owing to its use of a leadscrew nut acting as the output. Experimental results demonstrate the effectiveness of this approach, achieving individual and simultaneous actuation. This innovation offers a scalable solution for high-DoF robotic systems, providing a path to efficient actuation in robotic platforms.

Problem

• Robotics
• Energy Efficiency
• Mechanical Design

Innovation

• Clutch Control System
• Multi-Joint Efficiency
• Single Motor Drive