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One motor powers this robotic hand’s multiple grippers
Kanazawa University researchers built a robotic hand that switches between multiple grippers with one motor, using gravity to reroute torque.
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Robotic hands usually trade simplicity for versatility: handling many kinds of objects often means adding more motors, more control logic, or external tool changers. A team at Kanazawa University’s Institute of Science and Engineering says it has found another route, building a single-motor robotic hand that can switch between multiple grippers by using gravity as part of the mechanism.
The work, published in IEEE Robotics and Automation Letters, describes what the researchers call the “MaGDri (Magnetic and Gravity-based Driving) mechanism.” Instead of relying on extra actuators or complex control, the design uses gravity to switch the torque path, allowing different gripping units to be selected depending on the object being handled.
According to the researchers, prototype experiments showed that the hand could choose suitable grippers for objects with different shapes and sizes. The approach is notable because gravity is usually treated as a disturbance in robotics, but here it becomes part of the power-transmission system.
How the single-motor design works
Conventional robotic hands aimed at broad object handling often use either:
- multiple motors, or
- peripheral tool changers
This prototype instead keeps multiple grippers on the hand while driving them from one motor, with power transmission switched through a gravity-based mechanism. The team says that could reduce weight, space requirements, cost, and some of the failure and control complexity that come with more heavily actuated systems.
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The researchers see possible uses in settings where robots need to safely handle objects that vary in shape, size, weight, and rigidity—including households, nursing care and social welfare, stores, and logistics facilities. They also point to potential applications in industrial, domestic, care-support, mobility, and disaster-response robots.
The paper is “Single-Motor-Driven Robotic Hand With Multiple Grippers Using Gravity-Driven Torque-Path Switching Mechanism,” by Toshihiro Nishimura et al, published in 2026 in IEEE Robotics and Automation Letters. DOI: 10.1109/lra.2026.3685935.
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Dan is our resident futurist, covering electric mobility, space exploration, and the smart home. He's interested in atoms just as much as bits. Whether it's a new battery chemistry, a reusable rocket, or a protocol that finally makes IoT devices talk to each other, Dan breaks down the engineering that pushes humanity forward.
via TechXplore
