Radioplasmonics: design of plasmonic milli-particles in air and absorbing media for antenna communication and human-body in-vivo applications.

Surface plasmons with MHz-GHz energies are predicted by using milliparticles made of metamaterials that behave like metals in the radiofrequency range. In this work, the so-called Radioplasmonics is exploited to design scatterers embedded in different realistic media with tunable absorption or scattering properties. High-quality scattering/absorption based on plasmon excitation is demonstrated through a few simple examples, useful to build antennas with better performance than conventional ones. Systems embedded in absorbing media as saline solutions or biological tissues are also considered to improve biomedical applications and contribute with real-time, in-vivo monitoring tools in body tissues. In this regard, any possible implementation is criticized by calculating the radiofrequency heating with full thermal simulations. As proof of the versatility offered by radioplasmonic systems, plasmon “hybridization” is used to enhance near-fields to unprecedented values or to tune resonances as in optical spectra, minimizing the heating effects. Finally, a monitorable drug-delivery in human tissue is illustrated with a hypothetical example. This study has remarkable consequences on the conception of plasmonics at macroscales. The recently-developed concept of “spoof” plasmons achieved by complicated structures is simplified in Radioplasmonics since bulk materials with elemental geometries are considered.