Conical microstructures made of biopolymers for guiding and delivering light

Optical microstructures are of very high interest for delivering and or guiding optical radiation. Beyond the replacement of conventional hypodermic syringes, the use of microneedles opened the route towards portable lab on chip devices where the same microneedle could be used for drug delivery and photodynamic therapy, focusing the light thorough the needle tips. Here we propose for the first time an innovative approach for the fabrication of polymeric conical structures and the optical characterization of the light guided through a pyro-electrodrawn micro needle. A point-like thermal stimulation of a ferroelectric crystal enabled the electro-drawing of single or parallelized needles. The results reported show the possibility of tuning the geometry and the dimension of the structures produced and their use for controlling and guiding external light. The structures have been realized using a biocompatible and biodegradable polymer thus such conical structures in principle could be implantable. The conical structures have been characterized in terms of geometry, shape and emitted light profile. We report experimental results and discuss results and perspectives for exploiting them.