Design of an assistive wrist orthosis using conductive nylon actuators

This project outlines the design of an innovative wearable wrist orthosis which potentially can be used for rehabilitation therapy and for assisting with daily tasks. The orthosis uses recently discovered nylon artificial muscles as a means to actuate the device. Constructed from silver coated nylon sewing thread, these newly developed actuators have been shown to exhibit power to weight ratios that exceed that of human skeletal muscle. In this paper, we develop an electromechanical model for the force generated by the actuators and propose a simple closed loop controller to control the actuators. This system is then implemented in a wrist exoskeleton prototype to demonstrate the potential use of nylon actuators in biomedical applications.