Soft, Multichannel, Subcutaneous Electrical Junction for Long Term Ohmic Contact with Implantable Bioelectronics

Implantable bioelectronics are becoming an integral part of modern medicine, from drug delivery systems such as insulin pumps to responsive neural interface devices. To minimize the adverse effects of such implants, all components of the device should be soft and conformable, including the access port to the outside world. However, conventional wires or connectors require a permanent transcutaneous portal which increases the risk of infection, inflammation, and mechanical disruption. For this reason, wireless communication is preferred to allow complete implantation of the device without tissue-extruding components. However, the complexity of wireless communication combined with the associated rigid radiofrequency electronics inevitably result in bulkier and higher power consumption implants with limited applicability. Here, we developed a soft, subcutaneous, multichannel polymeric junction as an alternative approach to provide on-demand ohmic contacts with implants for exchange of data and power. Insertion of a patterned needle into this self-healable connector enables transmission of power and multi-channel, high-speed data. When not in use, the connection can be easily removed completely with no exposed components. This access port is made out of a three-dimensional conductive polymer structure sandwiched in an insulating stretchable polymer matrix. The healable properties of the polymers allow repetitive connections for long-term use. The electrical as well as mechanical properties of the synthesized materials were analyzed. The feasibility of the access port for implantable bioelectronics was validated with long-term chronic implantations in freely moving rodents to exchange power and neurophysiological data at the resolution of single neurons. We anticipate this approach will have a broad applicability to a wide range of implants and offer possibilities to improve patient quality of life.