The thesis presents the design and development of a low-cost, EMG controlled prosthetic arm that uses a scotch yoke mechanism as a driving system. The scotch yoke converts rotary motion into precise linear motion for the finger movement. The entire arm is 3D using PLA, enabling rapid prototyping, weight reduction and customization. A kinematic and FEA analysis was conducted to validate the mechanical design and structural integrity. Preliminary testing showed that EMG signals could control the opening and closing of the prosthetic. While functional, the current prosthetic arm has limitation in actuator stability and lacks a user socket.