Implantable electrical device comprising a substrate, encapsulation layer and adhesion layer

Abstract

Implantable devices require protection to protect a human or animal body from implant contamination and to protect implant electrical connections and electronics from corrosion. Although PDMS can be substantially biocompatible, it still has a relatively high permeability to moisture which can lead to degradation of the implant electronics. An implantable electric device is provided comprising: a flexible substrate having one or more electrical conductors and a first surface comprising a Liquid-Crystal Polymer (LCP); a first biocompatible encapsulation layer; a first adhesion layer disposed between the first surface and the first encapsulation layer; wherein: the first adhesion layer comprises a ceramic material; the first encapsulation layer comprises a silicone rubber such as a PDMS, and the first adhesion layer and the first encapsulation layer are configured and arranged to conform to the first surface and to resist the ingress of fluids into at least a portion of the first surface. By providing a bilayer having an encapsulant comprising a silicone rubber and a conformal adhesion layer comprising ceramic materials, the adhesion layer appears to show significantly higher stability in ionic media, thereby providing relatively longer protection in case of any delamination or water permeation through the encapsulant.