An under-actuated mechanism for a robotic finger

Robotic hands can be applied in different applications such as prosthesis, humanoid robots, industrial robotic manipulators and other kinds of robotic arms. Introduction of robotic technology into the field of prosthesis has resulted a higher quality of life for amputees. In this paper an under-actuated mechanism which has the self-adaptation ability is proposed to be used in the fingers of the hand prosthesis. The mechanism is a modification of the cross bar mechanism and it shows grasping adaptation ability for different geometries. In addition the mechanism is capable to generate dexterous grasping patterns making a paradigm shift from the conventional linkage mechanisms used for fingers which only has the capability for the grasping. Kinematic analysis, mathematical simulation and computer simulations were carried out to evaluate the effectiveness of the mechanism. Furthermore a new parameter, degree of adaptation is introduced to evaluate the performance of the under-actuated finger mechanisms.