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To date, various hand exoskeleton devices have been proposed. Most of them, however, contain linkage mechanisms which are relatively weighty. This research presents a novel lightweight hand exoskeleton robot, which is called Advanced Service Robots laboratory (ASR) glove. The glove is shape memory alloy tendon-based actuated which can be utilized for both rehabilitation exercises and assistance for people with hand disability. To realize the proposed glove, after the conceptual design of the proposed robot, the kinematics and force analysis of the system are elaborated analytically and also verified using an experimental prototype of the proposed device. The study shows that the proposed system can flex and extend fingers in their range of motion and grasp objects efficiently. The resulted tool is capable to exert extremely high force levels to grasp objects in various hand configurations. Also, using a 0.25-mm shape memory alloy wire, an angular movement of 80°, 90°, and 70° can be generated at the distal interphalangeal, metacarpophalangeal, and proximal interphalangeal joints of a finger, respectively. In addition, the total grasping force more than 40 N can be produced at the tip of the fingers.

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Purpose Many people suffer from injuries related to their hand. This research aims to focus on the improvement of the previously developed smart glove by using position and force control algorithms. The new smart glove may be used for both physiotherapy and assistance. Design/methodology/approach The proposed robot uses shape memory alloy (SMA) actuators coupled to an under-actuated tendon-driven mechanism. The proposed device, which is presented as a wearable glove attached to an actuation module, is capable of exerting extremely high forces to grasp objects in various hand configurations. The device’s performance is studied in physiotherapy and object manipulation tasks. In the physiotherapy mode, hand motion frequency is controlled, whereas the grasping force is controlled in the object manipulation mode. To simulate the proposed system behavior, the kinematic and dynamic equations of the proposed system have been derived. Findings The achieved results verify that the system is suitable to be used as part of a rehabilitation device in which it can flex and extend fingers with accurate trajectories and grasp objects efficiently. Specifically, it will be shown that using six SMA wires with the diameter of 0.25 mm, the proposed robot can provide 45 N gripping force for the patients. Originality/value The proposed robot uses SMA actuators and an under-actuated tendon-driven mechanism. The resulted robotic system, which is presented as a wearable glove attached to an actuation module, is capable of exerting extremely high force levels to grasp objects in various hand configurations. It is shown that the motion and exerted force of the robot may be controlled effectively in practice.