3-D PRINTED ORTHOTIC HAND WITH WRIST MECHANISM USING TWISTED AND COILED POLYMERIC MUSCLES

摘要

Most stroke victims undergo muscular disorders leading to weakening of muscles and inability to perform normal hand activities. An exoskeleton device is therefore needed to aid in performing basic hand movements to improve the quality of life of the victims. Most of the available devices in literature are controlled using electrical motors with a rigid structure and complex design. This paper discusses the design and performance of an inexpensive and lightweight 3D printed orthotic device featuring a wrist mechanism. The design is simple and utilizes twisted and coiled polymeric (TCP) muscles which are easy to fabricate using a silver coated nylon 6, 6 threads. The device facilitates the movement of all the three joints of the human finger namely, distal interphalangeal joint (DIP), proximal interphalangeal joint (PIP) and the metacarpophalangeal joint (MCP). Experiments were performed using a custom-made hand which was 3D printed and casted using silicone rubber with a shore hardness 10 (Ecoflex® 010) to resemble an actual human hand. The results showed the range of motion achieved with the device, grasping and pinching of various objects with assistive efforts using TCP muscles and demonstrated the capability of the device to achieve flexion and extension of the fingers mimicking the human finger movements.