The inability to monitor the molecular trajectories of whole organs throughout the clinically relevant ischemic interval is a critical problem underlying the organ shortage crisis. Here, we report a novel technique for fabricating manufacturing conformal microfluidic devices for organ interface. 3D conformal printing was leveraged to engineer and fabricate novel organ-conforming microfluidic devices that endow the interface between microfluidic channels and the organ cortex. Large animal studies reveal microfluidic biopsy samples contain rich diagnostic information, including clinically relevant biomarkers of ischemic pathophysiology. Overall, these results suggest microfluidic biopsy via 3D printed organ-conforming microfluidic devices could shift the paradigm for whole organ preservation and assessment, thereby relieving the organ shortage crisis through increased availability and quality of donor organs. / Master of Science / Organ failure is one of the most common cause of morbidity and mortality in humans. Unfortunately, there are not enough donor organs to meet the present demand, often referred to as the organ shortage crisis. To compound the problem, there is lack of understanding of the biological processes occurring in organs during the transplantation interval. Here, we present a method to manufacture a biomedical device using a 3D printing technique to monitor, collect, and isolate diagnostically relevant biological species released during the transplantation interval. This information has the potential to lead to a better understanding of organ health, which ultimately could increase the availability and quality of donor organs.