The goal of this project is to aid in the development of an implantable pump for patients with a failing Fontan circulation. These patients are increasingly surviving to adulthood and therefore require sustained support. Many blood contacting components of this pump are manufactured from poly-ether-ether-ketone (PEEK), for which biocompatibility has not been thoroughly characterized. This study will analyze surface characteristics of PEEK and compare them to previously characterized pump materials to analyze thrombosis potential.