Additive Manufacturing and Series Elastic Actuation for Hand Exoskeletons

Rehabilitation of the upper extremities, especially the hands, is critical for the restoration of independence in activities of daily living for individuals suffering from hand disabilities. There are currently two major challenges in developing robotic devices for hand rehabilitation: (1) design of a device that is compatible with the complex geometry and nonlinear biomechanics of the human hand and (2) actuation and control that leads to effective therapy through the exchange of suitable motion and forces between the device and the hand. We present the use of an additive manufacturing technique called Selective Laster Sintering for quick prototyping and a miniaturized series elastic actuator for force control of hand exoskeleton joints. We present the torque control results from experiments with an index finger exoskeleton, which is prototyped using additive manufacturing and is actuated by Bowden-cable-based series elastic actuators. Results showed that the device can be controlled to achieve accurate exoskeleton joint torque tracking while being highly customizable.