Microfluidic elastomer composites with switchable vis-IR transmittance

Abstract

We demonstrate a class of simple and versatile soft microfluidic materials that can be made optically transparent or coloured on demand. These materials are in the form of flexible sheets containing microchannel networks embedded in polydimethylsiloxane (PDMS). The channels are filled with liquids whose refractive index is matched with the one of the PDMS matrix. By pumping dye solutions into the channel networks and consecutively replacing the medium, we can control the material's colour and light transmittance in the visible and near-infrared regions.