Authors: Annick Mottard, Laval, Thierry Laliberté, Laval, Clément Gosselin
This paper discusses several design issues pertaining to the design of anthropomorphic underactuated robotic or prosthetic hands. The design of the underactuation mechanism that drives the fingers is first addressed. A double-stage mechanism is proposed that includes a lever arm to couple the motion of the thumb and the fingers as well as an additional pulley that amplifies the input force. Then, the design of the underactuated fingers is discussed and a novel rotational sliding joint is proposed. The geometric and mechanical design of a thumb mechanism is also presented that allows the reconfiguration of the thumb in the three most favorable poses. Finally, a prototype is presented that implements the design choices discussed in the paper and its effectiveness is qualitatively discussed based on a series of experiments.