MedRadio Medical Device Radiocommunications Service (MedRadio) band antifouling biomedical microrobot biotelemetry circular polarization coating conductive polymer drag reduce electrocardiogram (ECG) electrochemistry finite element analysis flextensional amplifier hearing loss high-density hydrophobicity implantable BCI implantable antenna implantable device implantable packaging lotus-like structure magnetic devices magnetic shielding mandibular advancement splint micro/nano electrode microelectrode array middle ear implant modified electrode obstructive sleep apnea patch antenna