Fig. 1: Robust underactuated 12-DOF robotic hand with 6 actuators.

One of the first robotic hands developed in the laboratory is the MARS hand (Main Articulé Robuste Sous-actionnée, i.e. robust underactuated robotic hand). Built in 1996, it is the result of a collaboration with l'Institut de Recherche en Santé et en Sécurité du Travail (IRSST), the Institute of health and safe work environments research. The objective was to design a hand which is both robust and has a large dexterity so that it can carry out a wide variety of tasks, including tasks in hostile environments (involving radioactivity, extreme temperatures, polluted air, etc.).

A prototype of the underactuated 12-DOF robotic hand with 6 actuators was thus built in 1996. The design process involved the use of a CAD software, various simulation programs, and the construction of a cardboard model. The hand is nearly twice the size of the human hand ans weighs 9 kg (20 lbs), yet, its maximum payload is 70 kg (155 lbs.). The hand is actuated by three brushless DC motors for the closing/opening of the fingers and three DC motors for orienting the fingers. The hand is capable of performing cylindrical, spherical and planar grasps with both power and precision grips. The prototype is capable of large enough forces to perform common industrial tasks. It is also equipped with tactile sensors.

The design of the robotic hand is protected by US patents (US 5,762,390) and a Canadian patent (CA 2 209 863 AA).

A poster on the MARS Hand was prepared in 2002 and can be downloaded with the following PDF file.

Several photos of the MARS Hand are provided below. They can be enlarged by clicking directly on the photos.

The MARS Hand can grasp objects of different shapes and textures. The following video segments illustrate several of these grasps.