Flexible, stretchable and implantable PDMS encapsulated cable for implantable medical device

Purpose: Diverse commercial implantable medical devices were developed for the convenience and life-quality of patients, and tether-free diagnostics and therapeutics. Those devices need implantable cable, which connects each part of their devices for transcutaneous energy or signal transfer. For prolonged implantation into human body, it should be safe, robust, and be long-term operable without failure. In this paper, we introduce an implantable PDMS-coated cable. Methods: By using PDMS as an encapsulation material, we developed a biocompatible, flexible and durable cable. Several tests were carried out for the evaluation of cable performance. Leakage test confirmed that coating using PDMS was sufficient to prevent the invasion of body fluid to conducting wire. Tensile test, torsion-durability test and bending-durability test demonstrated its mechanical durability and robustness to motion. The resistance variation recorded in the durability test was monitored to verify the electrical stability during movement of cable. Experiments of subcutaneous tissue implantation for 8 weeks were performed to observe the degree of biocompatibility as an implantable cable. Results & conclusions: Our cable was mechanically stable and biocompatible enough to be used for long term implantable medical devices.