Development of a Hand Robot Prototype for Low-Cost Prosthetics

Abstract

This research is aimed at developing a prototype robot hand for low-cost prostheses that can be used by those who lack the hand and allow them to hold light objects for everyday use. The construction of the prototype was carried out with different components obtained with 3D printing, which were assembled to obtain a robot hand. Also, actuators and an electronic control circuit were used for the generation of fingers movement. This investigation began with the study of the physiognomic characteristics of the human hand, mainly the movement of the fingers and their joints were analyzed, with which were determined the degrees of freedom and ranges of movement of each of the fingers. Each of the fingers has three degrees of freedom, three joints, and three links. The movement of each of the fingers of the prototype was performed with a servomotor and two ropes that run through the three links; turning the servomotor in one direction allowed the finger to extend and in another direction flexes, emulating in this way the movement of the human finger, although not perfectly. On the other hand, each finger is manipulated independently. The results of the tests shown that the prototype can successfully hold low weight and volume objects, so the prototype is considered reliable to hold everyday objects similar to those used during the tests. At this stage of the investigation, there have been no tests with patients. Research for the development of this prototype is open to refinement and optimization of the model. The material used for the construction of the prototype can be lighter, the mechanical and electronic system that moves the fingers can be improved and the energy sources that feed the system can have greater autonomy.