Abstract
Finger actuation mechanisms were investigated to aid the development of a low-cost prosthetic hand. A novel method was used to assess the finger actuation mechanisms individually as opposed to assessing the entire hand. This has the benefit of enabling the finger designs to be applied to multiple hand designs. Each finger actuation mechanism consisted of a finger design and a driver. The three finger designs considered were the Tact finger; a derivative of the OpenBionics hand, denoted the Channel finger; and a 4-Bar Linkage finger. The two actuation drivers tested for each finger were a solid-bar linkage system and a pulley system —both of which are motor-driven. The finger actuation mechanisms were assessed based on the force produced, movement precision, degrees of movement, power consumption, contraction and extension times, and mass. A weighted summation method was used to aggregate the results into a score for each finger design. The motor-driven linkage systems outperformed the motor-driven pulley systems with the 4-Bar linkage finger being the best-performing finger actuation mechanism overall. It was recommended that the number of actuation mechanisms be expanded to provide a more comprehensive set of results. Different motors should be tested to improve the force produced to bring it in line with an average human finger.
