DESIGN AND PROTOTYPING OF A LOW-COST, LINKAGE-DRIVEN TWO-FINGER EXOSKELETON FOR HAND REHABILITATION

Abstract

Hand rehabilitation remains a key element in restoring motor functions among individuals affected by neurological injuries such as stroke; robotic-assisted therapy has demonstrated therapeutic effectiveness in prior studies. The practical use of current hand exoskeletons remains restricted due to elevated costs and complex designs; this limitation is more pronounced in healthcare systems operating with reduced financial and technical resources. Existing research lacks a verified system that delivers essential finger mobility through a structure that is both low-cost and simple; few designs can be fabricated using basic materials and tools. The main focus of this investigation was the mechanical development and preliminary evaluation of a hand exoskeleton employing a planar linkage system to guide the motion of the index and middle fingers. A solid model was produced using CAD software; the final device layout was based entirely on this model and ensured accurate component dimensions and assembly alignment. The fabricated prototype utilized laser-cut acrylic linkages; actuation was achieved through standard servo motors; a bevel gear pair delivered the mechanical transmission. The control mechanism was managed using an Arduino microcontroller; the electronics were programmed to control finger trajectories based on predefined flexion-extension angles. This prototype introduced a functional concept of mechanical simplicity; the six-bar linkage system employed only easily available elements assembled into a precise therapeutic motion unit. The complete prototype system weighed close to 100 grams; total expenditure for materials remained under $50 USD; no specialized components were required for construction. Device tests showed controlled finger movements in flexion and extension; the outcomes verified mechanical integrity; actuation reliability and electronic responsiveness were confirmed during performance trials. These findings support the potential of a mechanically feasible and economically accessible device; the demonstrated framework holds value for expanding therapy access in underserved healthcare settings. The study confirms that reliable finger mobilization may be delivered through affordable robotic mechanisms; the approach may improve recovery conditions for patients experiencing hand paralysis or post-stroke motor deficits.