UniServices Commercialisation
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Compact four-output differential for prosthetics and exo-gloves

Categories for this Technology

Robotics, prosthetics, wearables


Intellectual Property

PCT Application filed July 2020 (available on request)





A compact, robust, and energy efficient differential system for distributing torque from one electric motor across four outputs. Designed to increase the actuation and grasping capabilities of soft exoskeleton gloves and adaptive prosthetic systems while guaranteeing reduced cost and complexity.


Problems Addressed

Soft, underactuated, and wearable robotic exoskeleton gloves can improve the capabilities of healthy individuals or assist people suffering from neurological and musculoskeletal diseases. Most existing solutions utilise individual motors to control each finger independently, which increases weight, cost, and complexity. Commercially available prosthetic devices use individual motors for every finger and rigid transmission systems that transfer the forces to the prosthetic fingertips. Such design choices make the prostheses heavy, expensive, bulky, difficult to maintain, hard to operate, and provide limited operation autonomy (due to increased power consumption).



Typically, a differential mechanism has two outputs and its most popular application is in the automobile industry, where the differential allows the wheels to rotate at different speeds.

The New Dexterity research group at the University of Auckland has developed a novel four-output differential, which distributes the torque provided by one motor to four outputs connected to the fingers of an exoskeleton glove or a prosthetic hand. Such a mechanism allows the fingers to passively adapt to the shape of objects during the grasp, maximizing the contact points. Maximization of the contact areas during grasping leads to the maximization of the grasp stability.

A paper, titled An Underactuated, Tendon-Driven, Wearable Exo-Glove With a Four-Output Differential Mechanism, was published in 2019 which describes the technology in more detail. A video of the system in action can also be viewed here


* Full prosthetic hands
* Partial hand prostheses
* Exoskeleton glove systems
* Wearables


* Enables exoskeleton gloves and prosthetic hands to offer increased dexterity at affordable cost, without compromising usability and grasp stability.
* Provides grasping capability enhancement to the user
* Removes need for bulky differential mechanisms or multiple actuator units
* Outputs can move independently of each other, so if one finger is blocked from moving, the rest can still move and maximise the grasp stability.


Questions about this Technology?

Contact Sam Wilkins