This project aims to develop a lightweight, low-cost orthotic glove that enhances grip strength for individuals with impaired hand mobility, particularly those with osteoarthritis. Unlike existing solutions—such as surgery or restrictive orthotics—this glove uses a passive mechanical system that keeps the hand naturally closed using flat coil springs. To open the hand, a motor-driven pulley system pulls cables attached to the fingertips, working against the spring tension.
The glove's control system includes force sensors that allow users to open their hand with a light touch, minimizing effort. A proportional controller adjusts grip strength based on user input, enabling both "low power" (partial opening) and "high power" (full opening) modes to conserve energy. Key innovations include a force-actuated pulley system that ensures even finger movement, 3D-printed finger rings for component alignment, and a custom knuckle housing to manage mechanical stresses. The glove operates via a finite state machine coded in Arduino, translating sensor input into grip behaviors ranging from soft to firm.
Full Assembly With Two-Finger Actuation Control.
The above is an FEA of the knuckle housing that contained the majority of components, such as the motor and aluminum shaft. Due to the amount of torque that is required of the motor to turn the pulleys with the springs pretensioned, it was clear that there will be force pushing against the sides of the 3D printed housing. The FEA is set up so the area that covers the knuckles are the fixed points while the force is acting on the sides where the motor is screwed in and where the shaft is pushing against on the other side. The results show that the von Mises stresses are manageable and are under the yield strength of the PLA material so it will not yield as a result of the motor.