School of Mechanical Engineering
Conventional wearable robots, comprised of rigid joints and links, are very limited in providing proper assistance for people in need on a daily basis. Commonly used actuators and sensors make it challenging for researchers and engineers to design compact and lightweight wearable systems which would be truly mobile and non-restrictive for the wearer. In our work, we are focused on developing lightweight compliant actuators and implementation of novel actuation principles that can eliminate the use of rigid structures. We have been working on design of elbow and upper-limb exoskeletons based on cable-driven and twisted string actuators. We would like to share our experience and point of view with clinicians, therapists and fellow engineers in order to develop practical lightweight and mobile assistive systems.
Twisting String Actuator (TSA) is powerful and compact linear actuator, in which a string or a set of strings connected to an electric motor act as a gear. When a load is attached to the string on the other end, the rotation imposed on the string by the motor will reduce the length of the string, thus causing the translational motion of the load due to the generated pulling force. Such actuators can be very light, cheap and quiet and provide a high (though nonlinear) transmission ratio, which makes them very attractive for use in various areas of engineering, such as robotics.