CONCEPTUAL DESIGN AND VIRTUAL PROTOTYPING OF A COMPLIANT, LOW-COST PROSTHETIC HAND

This paper presents the development of an underactuated prosthetic hand that offers a cost-effective, functional, and human-like alternative for individuals with upper limb amputations. The design and virtual prototyping of the hand focus on achieving a size, weight, and appearance that closely resemble a human hand, aiming to enhance user acceptance. The prosthetic hand consists of ten degrees of freedom (DoF), with four of them being actuated. Among these, three degrees of actuation (DoA) are controlled by electric motors and a tendon transmission system, while the remaining DoA is manually actuated by the user through a spring plunger. The underactuated design incorporates compliant hinges based on springs and a mechanism that decouples the motors from the fingers, enabling more natural movements and greater adaptability to different objects. By incorporating a tendon transmission system and manual thumb actuation, users can easily accomplish basic grasping tasks without relying on complex control systems. To evaluate the gripping abilities and maximum gripping force of the hand, a virtual prototype has been created and tested in different grasping scenarios. This assessment allows for performance evaluation and refinement of the design. To improve affordability and accessibility for a wider range of users, the prosthetic hand has been designed with a focus on cost-effective components and widespread utilization of additively manufactured parts.