Implantable antenna gain enhancement using liquid metal-based reflector

• Published in: Applied physics. A, Materials science & processing Materials science & processing, 2020, Vol.126 (9), Article 738
• Main Authors: Das, Soumyadeep, Mitra, Debasis, Mandal, Bappaditya, Augustine, Robin
• Format: Article
• Language: English
• Subjects: Antenna gain; Applied physics; Biocompatibility; Biomedical application; Casting; Characterization and Evaluation of Materials; Condensed Matter Physics; Directivity; Electronic implants; Frequency selective surfaces; FSS reflector; Gain enhancement; Human tissues; Implantable antenna; Liquid metal; Liquid metals; Machines; Manufacturing; Materials science; Microfluidics; Nanotechnology; Optical and Electronic Materials; Physics; Physics and Astronomy; Polydimethylsiloxane; Pork; Processes; Slot antennas; Surfaces and Interfaces; Thin Films
• ISSN: 0947-8396; 1432-0630; 1432-0630
• DOI: 10.1007/s00339-020-03862-2

This article presents gain enhancement methodology for a dual-ring slot antenna using a frequency selective surface (FSS) as reflector. The FSS structure is formed with liquid metal placed inside the microfluidic channels created on the surface of the polydimethylsiloxane. Non-toxic liquid metal galinstain has been used to ensure biocompatibility. The FSS structure is placed below the ring slot antenna to reflect the back radiation, which in turn enhances the antenna directivity. Subsequently, the antenna gain has been increased as well. A fabricated prototype of the antenna-FSS system, operating at 2.45 GHz, has been analysed both inside human tissue mimicking fluid and pork slab to validate the simulation results. The inclusion of the liquid metal-based reflector increases antenna gain by almost 4 dB as well as ensures required biocompatibility and flexibility. Also the specific absorption rate of the antenna is observed to be reduced.