Optical fiber sensor layer embedded in smart composite material and structure

Abstract

A composite structure health monitoring system with optical fiber sensors is an importantdevelopment in smart materials and structures. But it is difficult to embed a network ofdistributed optical fiber sensors in a smart composite structure, and the most effectivemethod would be integrating the network of sensors with the polyimide film as a layer,called the optical fiber sensor layer, and then embedding the layer with opticalfiber sensors in the composite material. This paper introduces three methods ofmaking a distributed optical fiber sensor layer with polyimide. The first is tosandwich optical fiber sensors in two polyimide films. The second is to deposit thenetwork of sensors in polyimide solution, and dry the polyimide solution. The last isto build thin-film optical waveguides and optical sensors by using fluorinatedpolyimide, which is expected to have high integration and high reliability. Sometests indicate that there is a little influence on the mechanical performance ofthe structure; however, optical fiber sensor built-in polyimide films work verywell.