Foldable and Cytocompatible Sol-gel TiO[subscript 2] Photonics

Integrated photonics provides a miniaturized and potentially implantable platform to manipulate and enhance the interactions between light and biological molecules or tissues in in-vitro and in-vivo settings, and is thus being increasingly adopted in a wide cross-section of biomedical applications ranging from disease diagnosis to optogenetic neuromodulation. However, the mechanical rigidity of substrates traditionally used for photonic integration is fundamentally incompatible with soft biological tissues. Cytotoxicity of materials and chemicals used in photonic device processing imposes another constraint towards these biophotonic applications. Here we present thin film TiO[subscript 2] as a viable material for biocompatible and flexible integrated photonics. Amorphous TiO[subscript 2] films were deposited using a low temperature (
National Science Foundation (U.S.) (Award 1453218)
National Institutes of Health (U.S.) (Award R01DC011377)