Current antennas used for communication with implantable medical devices are connected directly to the titanium device enclosure, but these enclosures are shrinking as batteries and circuits become smaller. Due to shrinking device size, a new approach is needed that allows the antenna to extend beyond the battery pack, or to be entirely separate from it. Softer properties are needed for antennas in direct contact with body tissues. This must be achieved without compromising the high electrical conductivities and stabilities required for acceptable performance. Here, a nanocomposite based approach was taken to create soft, biocompatible antennas that can be embedded in the fat layer as an alternative to the metallic antennas used today. The nanocomposite films combine the exceptional electrical conductivity, biocompatibility, and biostability of Au nanoparticles with the mechanical compliance, biocompatibility, and low water permeability of polyurethane. Nanocomposite film synthesis utilized flocculation and vacuum assisted filtration methods. The soft antenna films display high conductivities (∼103 S/m–105 S/m), reduced Young’s moduli (∼102 MPa–103 MPa), exceptional biocompatibilities characterized by in vivo and in vitro work, and notable biostabilities characterized by accelerated degradation studies. Consequently, the nanocomposite antennas are promising for chronic in vivo performance when the conductivity is above 103 S/m.

Highly conductive nanocomposite hydrogels have been challenging to produce due to their high water volumes inhibiting the incorporation of an essential amount of conductive nanofillers. Furthermore, the most common fillers...

This article is an initial exploration of the material effects of subdermal antennas in the fat layer under the skin for the MedRadio band (401–457 MHz) through the Industrial Scientific Medical 902–928 MHz. Subdermal strip dipoles were made of materials with conductivities ranging from 5.0 × 103 to 5.8 × 107 S/m, including a biocompatible gold nanoparticle polymer.