Robotics-driven printing of curved 3D structures for manufacturing cardiac therapeutic devices

Cardiovascular disease (CVD) is the leading cause of death in the United States. 3D printing technology has increasingly paved its way into cardiovascular applications, in particular for manufacturing cardiac therapeutic devices. However, currently available commercial 3D printers and those under development exclusively work by successively depositing layers of material using axis-aligned slicing methods, thus need unacceptably high demand of support materials and even fail fabricating for some complex cardiovascular structures, not to mention printing for the purpose of repairing an existing abnormal strictures. To solve this problem, we propose and develop a novel and robust robotics-driven printing system, consisting of a robotic arm and an extruder tool to allow printing along trajectories on any curved surface. Given the target structure, a new set of algorithms for robot toolpath planning was implemented, which include mesh parameterization, distance transform, contouring and smooth interpolation. Using both simulation and actual physical testing, we showed our system can successfully print layers of the target structure on curved geometry by following planned tool paths and depositing materials. In this paper, we describe our methodology and algorithm pipeline, compare and analyze the printing results of different techniques, and most importantly, envision the promising future extension of our robotics-driven printing system in manufacturing cardiac therapeutic devices.