Flexible, Adhesive, and Biocompatible Bragg Mirrors Based on Polydimethylsiloxane Infiltrated Nanoparticle Multilayers

Herein we present a series of self-standing, flexible, and biocompatible optical interference filters obtained through infiltration and polymerization of an elastomer (polydimethylsiloxane) in a porous Bragg mirror prepared by alternating deposition of layers of TiO2 and SiO2 nanoparticles. The method proposed yields the uniform filling of the nanopores of the multilayer by the polymer, which allows lifting off the hybrid structure as long as the ensemble is cooled to temperatures below the glass transition of the polymer. This multifunctional material combines the optical properties of the periodic nanoporous multilayer and the structural and physicochemical characteristics of polydimethylsiloxane. Experimental demonstrations of their potential use as flexible and adhesive UV-protecting filters, as well as of light, highly-efficient conformal back reflectors to enhance the efficiency of photovoltaic devices are provided.