Flexible Photonics Embedded into Advanced Composites

Flexible and stretchable photonics is a rapidly evolving area, with various materials, design, processing, and device technologies being explored [1] . As with flexible electronics, flexible photonics particularly lends itself to integration upon engineered and natural structures, such as interfacing with the soft, curvilinear, and dynamic surfaces of living organisms. Here we explore a potential new growth opportunity interfacing with engineered structures, namely embedding into advanced composite materials (such as Carbon Fibre Reinforced Polymer and Glass Fibre Reinforced Polymer). The motivation being ultimately new optical functionality and intelligence for engineered structures (e.g. wind turbines, aircraft, civil infrastructure), going beyond what has been developed with embedded optical fibre through realising the full geometric diversity offered by flexible photonics. This work embeds ultra-thin glass [3] , utilising its flexibility in order to be conformal to the shape of composite structures which flex and in parts are non-planar. It is noted that cyclic olefin copolymer planar chips have recently shown feasibility in composite material [2] , whilst these demonstrations use rigid planar optics they do show feasibility for other flexible photonic materials to exploit this application.