PREPARATION OF A HUMAN SKIN-MIMICKING GELS FOR IN VITRO MEASUREMENTS OF THE DUAL-BAND MEDICAL IMPLANT ANTENNA

Abstract

The purposes of this study are to design of a small size implantable antenna and to present a complementary recipe for a human skin mimicking material for in-vitro testing of implantable antennas operating at MICS (Medical Implant Communications Service, 402–405 MHz) and ISM (Industrial, Scientific, and Medical, 2.4 GHz–2.48 GHz) bands. Approximate electrical properties of human tissues at MICS and ISM bands were obtained by mixing de-ionized water, sugar, NaCl, and Poly(acrylic acid) (PAA or Carbomer) with different content percentages. In the literature Agarose, a polysaccharide polymer material, was widely used to ensure the formation of gel of the mixture and in our study we used Carbomer instead of Agarose for this aim. To test the antenna in-vitro, skin mimicking gels were made that to show electrical properties real skin tissue (relative permittivity ( e r ) and conductivity (σ)) for the operation frequencies of ISM and MICS bands. For the antenna performance evaluations the measurements of the antenna (return loss (S 11 )) have been performed by placing in to the skin mimicking gels. The measurements were taken in the 1 GHz - 5 GHz frequency band. The measurement and simulation results are quite good agreement except some discrepancy in S 11 levels and frequency bands.