Figure 6

The return loss (\({\mathrm{S}}_{11}\)) per frequency for (a): first (\({f}_{01}\)) and second (\({f}_{02}\)) resonance frequencies, (b) first resonance frequency (\({f}_{01}\)), (c) second resonance frequency (\({f}_{02}\)) (line a: no MUT, line b: arm as MUT with no activity, line c: arm as MUT after 1 min activity, line d: arm as MUT 3 min after starting eating honey).