Tunable metasurface devices based on soft matter

Soft matter materials constitute an exciting platform to introduce flexibility, versatility and tunability into metasurface devices. Despite the low refractive index of polymers, soft matter materials can be effectively employed either as the base meta-atoms, or in composite with solid-state dielectric nanoresonators, for tunable metasurfaces. In this chapter we introduce the physical mechanisms enabling soft matter-based metasurfaces and provide an overview of the existing platforms for static and dynamic soft matter metasurfaces, including metasurfaces that can be tuned electrochemically, optically and thermally. We also provide an overview of soft matter used in combination with solid-state dielectric metasurfaces to introduce tunability, including as flexible substrates, dynamic coatings and refractive index tuning. We conclude by discussing the key challenges and opportunities for the widespread implementation of soft matter metasurfaces.