Coiling an optical fiber for long-range dynamic displacement and force sensing

Abstract

Optical fiber sensors have been applied on detecting various physical parameters. In this work, inspired by the mechanism of tendril coiling, we designed a spring-like sensor using optical fibers based on macro bending loss. The proposed optical-fiber spring has good elasticity like a mechanical spring and thus can be used to measure large displacement. As a contact-type sensor, the fabricated optical-fiber spring can measure dynamic displacement, whose range is 4 orders of magnitude higher than that of the point-wise fiber Bragg grating displacement sensor. In addition to the point-wise displacement sensing, we further integrated the optical-fiber spring with a Kresling origami to form a force sensor.