Development of String Type Flexible Displacement Sensor and Its Application

Abstract

An importance of wearable devices in the field of medical treatment such as nursing care and rehabilitation has been strongly recognized. Also, the development of the power assisted device has been done to support the nursing care work for the elderly. The purpose of our study is to develop a flexible displacement and bending sensor which can measure the movement of human body, flexible actuator or flexible joint of the robot by mounting on the surface of them. The developed string type flexible displacement sensor (FDS for short) consists of two fixed electrodes, a slide electrode and a nylon string coated with carbon (NSCC for short). It works as a flexible potentiometer by sliding the slide electrode along NSCC while it keeps the electrical contact. In order to keep a stable contact even if NSCC bends flexibly, the slider is consisted of a brass cylinder filled with carbon black powder. We confirmed that the proposed sensor worked well by carrying out the position control of a McKibben artificial muscle with the tested sensor installed on the surface of the muscle.