A single-actuator prosthetic hand using a continuum differential mechanism

Substantial progresses have been made in building versatile anthropomorphic prosthetic hands in the past two decades using emerging technologies. However the trade-offs between functionality, reliability, affordability, appearance, etc. have not been fully settled. Many existing designs, particularly the commercial prosthetic hands, are underactuated and they can realize various grasps through compliant structures or differential mechanisms. This paper presents the design of an underactuated prosthetic hand with one actuator using a continuum differential mechanism. Structure of the continuum differential mechanism is simple enough to allow all the components, including a battery pack, to be packed into the palm. The design concept, component descriptions, and hand constructions are elaborated. Experimental verifications are presented to demonstrate the efficacy of the proposed design.