National University of Singapore1
Rehabilitation is crucial for patients with neurological disorders that cause motor impairments. However, there is a shortage of physiotherapists available to provide daily rehabilitation. Traditional rigid devices are bulky, expensive, and possess safety risks to users. Therefore, this project aims to develop a low-cost and portable hybrid robotic arm for safer human-robot interactions.
The hybrid robotic arm consists of beam modules, joint modules and an end-effector.
Beam modules have rigid inner supporting cores and soft outer protective layers that are made of inflatable fabric. Joint modules have rigid inner hinge joints and soft outer air bladders to control the bending motion of the joint modules. End-effector consists of soft actuators for compliant gripping.
The arm is mounted onto a movable platform and the base of the robotic arm is able to achieve motions in 2 axes (up-down, left-right). All the fabric air bladders are pneumatic driven, and all the actuation and control systems are integrated into a single controller pad. All modules of the hybrid robotic arm are exchangeable, which allows the robotic arm to vary its length or exhibit various configurations.
The hybrid arm demonstrated higher force applications compared to existing soft robotic arms, and lower weight and cost compared to existing rigid robotic arms. It was tested successfully with various configurations to lift a mannequin that weighs about 800g.
The hybrid robotic arm can provide safer human-robot interactions and exhibit various configurations according to different applications, at the same time providing sufficient force to assist rehabilitation.