A Subcutaneous Biochip for Remote Monitoring of Human Metabolism: Packaging and Biocompatibility Assessment

This paper represents the extended version of the conference paper “Developing highly-integrated subcutaneous biochips for remote monitoring of human metabolism” presented at the IEEE Sensors Conference 2012, and presents data on assembly, packaging and short term
in vitro
and
in vivo
biocompatibility evaluation of a fully implantable biosensor array. The device was realized integrating three building blocks: 1) a multielectrode platform; 2) an inductive coil; and 3) an integrated circuit. The entire system measures 2.2 mm
$\times 2.2$
mm
$\times 15$
mm. Corrosion of electronic components and leaking of potentially hazardous substances in the body is prevented with a conformal coating of Parylene C, while an outer package of medical grade silicone was employed to create a soft shell suitable for implantation. Biocompatibility experiments did not show
in vitro
cytotoxicity in the considered period of 7 days, while comparison between 7 and 30 days
in vivo
implantations showed significant reduction of the inflammatory response in time, suggesting normal host recovery.