A Wearable Soft Robotic Glove for Rehabilitation of Paralyzed Hand

Abstract

Stroke attacks are the one of major reason in hindering the human hand functionality and cause disability. Soft robotic is playing a major role in rehabilitation where different robotic gloves are being developed. Due to light weight, portability and safe human- robot interaction, soft robots are best alternative of rigid robots. Soft pneumatic actuators were designed and fabricated with three different silicon materials. Silicone materials were chosen because of low cost and locally availability. Three different materials for fabrication are RTV 225, RTV 4503 and Elastosil M4600. Tensile tests were done on each material specimens for material properties. Uniaxial tensile test tests were done with speed of 100 mm/sec on Zwick 10 testing machine with dog bone specimen. Elastosil M4600 shows the highest elongation (700%), tensile strength and modulus while RTV 225 shows the medium elongation (500%), tensile strength and modules. RTV 4503 shows the lowest elongation (200%), tensile strength and modulus. Actuators were tested for blocked force generation, actuation speed, bending angle, bending time and full bending pressure. Soft actuators showed the initial bending due to softness and gravity. Elastosil M4600 actuator showed the initial bending of 49° while RTV 225 and RTV 4503 shows 59° and 53° respectively. Elastosil M4600 achieved full bending at 58kPa while RTV 225 and RTV 4503 achieved full bending at 48kPa and 51 kPa respectively. RTV 225 showed the fast response as compared to two other actuators. Elastosil M4600 actuator shows the block force of 1.36 N, RTV 225 shows 1.13N and RTV 4503 shows 1.03 N at full bending pressure. Elastosil M4600 actuators shows the highest bending angle of 166° at full bending where RTV 4503 have bending angle of 143° at full bending while RTV 225 have bending angle of 144° while achieved the full bending. Three soft robotic grippers were assembled. 3D printed connector and base were used to assembled the soft grippers. Different objects having different shapes, sizes and weights were chosen to test the ability of soft robotic grippers. Result shows the reliable grasping of objects. Soft robotic gloves were assembled and tested for daily living activities and rehabilitation purpose. Four different objects were chosen to test the grasping ability of soft robotic glove. Kapandji test was done with RTV series actuators to validate the postures of rehabilitation test. Tests were done on healthy object. Result shows the reliable grasping and rehabilitation exercise.