Towards Resorbable Elastomeric Circuit Boards for Implantable Medical Devices.

IMDs are typically considered for chronic-use applications and a limited set of implant locations. Resorbable IMDs seek to combine advances in flexible electronics with functional soft materials to enable new applications, including acute care, aiming at temporary interfacing with soft tissues. Poly(oc-tamethylene maleate (anhydride) citrate) (POMaC) is an elasto-mer with demonstrated high biocompatibility and bioresorbability, as well as tunable stiffness and surface properties. Despite its promises, POMaC has not yet been applied in engineering flexible electronics. Herein, a POMaC-based circuit board is demonstrated and characterized. The monomer composition and thermal degradation properties of the pre-polymer was characterized. POMaC-based circuit boards were constructed using traditional microfabrication methods, including spin coating and metallization. POMaC pre-polymer and films were thermally stable to 300°C, exhibit controlled degradation in simulated physiological conditions, and are cytocompatible. Deposited traces were stable during fabrication and processing, and an LED circuit was designed and fabricated using surface mount devices on a POMaC-circuit board. The results indicate the feasibility of POMaC-based circuit boards for use in resorbable IMDs. Future work will investigate more complex circuits, fully encapsulated devices, and mechanical characterization.