Multifunctional Integrated Optic Sensor for Detection of Cracks and Corrosion

Los Gatos Research proposes to develop a new nondestructive inspection sensor system, capable of simultaneously measuring strain-based load and detecting crack, corrosion, and disbonding in inaccessible areas of aerospace structures. Our novel sensor technology offers a number of advantages including compactness, lightweight, low power consumption, and high sensitivity. We achieve this by fabricating Bragg gratings on stress-wave-sensitive polymer planar waveguides, which is capable of detecting both surface and below surface cracks and stress in aerospace structures. In Phase I, using a guided wave method we will demonstrate the polymer gratings' capability to measure strain and stress waves indicating the presence and severity of damages caused by cracks, disbonding, or corrosion in a thin metal structure, when the structure is probed by a conventional ultrasonic wave generation device. In Phase II, an integrated optic Bragg grating-based load monitoring and guided wave sensor prototype and a crack detection algorithm will be developed to provide structural health monitoring and nondestructive evaluation for spacecraft composite systems and components.