3D Printed Soft Robotic Hand Combining Post-Stroke Rehabilitation and Stiffness Evaluation

Soft rehabilitation devices have been invented and applied for hand function recovery. In this paper, we propose a new Ring-reinforced 3D printed soft robotic hand, which combines hand rehabilitation and joint stiffness evaluation. The elastomer body of Ring-reinforced Soft-Elastic Composite Actuator (R-SECA) is 3D printed directly for fitting different sizes of fingers and the Iterative learning model predictive control (ILMPC) algorithm is used for controlling. Torque compensating layer inside R-SECA enables finger flexion and extension despite finger spasticity. Plastic rings are used to refrain radial expansion and reinforce the actuator. Bending angle and output tip force at different air pressure inputs are explored with four different R-SECA (120 mm, 112 mm, 96 mm, 72mm length). Four-stroke survivors are recruited to evaluate the effectiveness of the soft robotic hand, and hand function improvement can be observed from the clinical evaluation data and stiffness evaluation outcomes.