[pythonguython]

It sounds more complicated than it is. A metasurface is almost always just a fancy patch antenna. If you reduce some parameters down, you can really just view it as a resonant circuit. You could design a meta surface in a few minutes in any pcb design software and get it fabricated on low tech PCB fabrication equipment. In this case, they used an array of a specific type of patch antennas (that’s a meta surface) called the complementary split ring resonator. In a sense, all split ring resonators are “micro radar” surfaces, because a split ring resonator is designed to be electrically small compared to the wavelength. The researchers here found that the change in glucose in the bloodstream changes the dielectric properties of the bloodstream, and the resonant characteristics of the complementary split ring resonator change depending on the surrounding dielectric (a dielectric just describes the electrical properties of a material - for instance, a higher electric dielectric constant will slow down the phase velocity of an EM wave, which leads to various measurable effects in an RF system). Looks like great engineering work here, but I’ve always thought the term “metasurface” was foo foo jargon since I first began studying antennas.