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.

中文翻译：

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用于植入式皮下天线的生物稳定导电纳米复合材料

当前用于与植入式医疗设备通信的天线直接连接到钛设备外壳，但随着电池和电路变得更小，这些外壳正在缩小。由于设备尺寸不断缩小，因此需要一种新方法，使天线能够延伸到电池组之外，或者与电池组完全分离。与身体组织直接接触的天线需要更柔软的特性。这必须在不影响可接受性能所需的高导电性和稳定性的情况下实现。在这里，采用基于纳米复合材料的方法来制造柔软的、生物相容的天线，可以嵌入脂肪层，作为当今使用的金属天线的替代品。纳米复合薄膜结合了卓越的导电性、生物相容性、Au纳米颗粒的生物稳定性和聚氨酯的机械顺应性、生物相容性和低透水性。纳米复合膜合成利用絮凝和真空辅助过滤方法。软天线薄膜显示出高导电性（~103 S/m–105 S/m）、降低的杨氏模量（~102 MPa–103 MPa）、以体内和体外工作为特征的特殊生物相容性以及以加速降解为特征的显着生物稳定性学习。因此，当电导率高于 103 S/m 时，纳米复合天线有望实现长期的体内性能。软天线薄膜显示出高导电性（~103 S/m–105 S/m）、降低的杨氏模量（~102 MPa–103 MPa）、以体内和体外工作为特征的特殊生物相容性以及以加速降解为特征的显着生物稳定性学习。因此，当电导率高于 103 S/m 时，纳米复合天线有望实现长期的体内性能。软天线薄膜显示出高导电性（~103 S/m–105 S/m）、降低的杨氏模量（~102 MPa–103 MPa）、以体内和体外工作为特征的特殊生物相容性以及以加速降解为特征的显着生物稳定性学习。因此，当电导率高于 103 S/m 时，纳米复合天线有望实现长期的体内性能。