A low-cost, compliant, underactuated prosthetic hand with custom flex sensors for finger bending estimation

Access to quality prosthetics to aid in daily activities is a privilege of only 5 % of those in need of such equipment. It is noted that the high cost of these, associated with the lack of skilled labor, are two of the factors that aggravate the situation. Thus, the need for cost-effective prosthetic technologies, targeting the population of developing countries, is observed. Inspired by this problem, this paper presents the process of conceptual study, design, and prototyping of a low-cost prosthetic hand that is compliant and underactuated. The hand has a wrist of two degrees of freedom, and five independently actuated fingers. One of the main contributions of this work is the design of a low-cost optoelectronic sensor for the finger's curvature estimation.