Low‑Cost Prosthetic Arm with Tendon‑Driven Mechanism and Intuitive Muscle Control

Advanced prosthetic limbs are prohibitively expensive (> 2000 USD), putting them out of reach for most amputees in developing countries. We propose a low‑cost prosthetic arm (< 60 USD) using only two servo motors (SG90 for grip, MG996R for wrist) and a tendon‑driven mechanism instead of one motor per joint. The user controls the arm with a single muscle (via an EMG sensor or a potentiometer) using a tap‑counting logic (short contraction, double short contraction, long contraction). Eight pre‑programmed positions (full grip, precision grip, mouse grip, hook grip, pointing, key grip, rest, touch mode) cover most daily tasks. This paper presents the theoretical design, estimated cost, and future development (integrating an LLM to generate new grip positions using natural language).