Design of a 3D UV-Silicone Printing Machine for Complex Geometry Printing

Additive manufacturing has impacted healthcare by reducing surgery durations and anesthesia exposure, enhancing pre-surgical planning, and enabling the creation of patient-specific replicas of bones and tissues. The integration of handheld ultrasound, CT scanning, and X-ray imaging with 3D printing has further changed the medical field, offering possibilities for bioprinting and organ replacement. Traditional heart valve replacements, often constructed from metallic or bio-prosthetic tissues, incur substantial labor and financial costs, limited durability, and the need for immunosuppressive or anti-thrombogenic drugs. Additionally, the unique anatomy of each patient's aorta creates challenges for the precise fit of circular replacement valves. The range of materials available for 3D printing within the healthcare industry is narrower compared to conventional manufacturing techniques. Materials such as silicone rubber, known for its biocompatibility, flexibility, and thermal stability, are highlighted as adaptable materials, presenting opportunities for manufacturers of medical devices involved in 3D printing. While there are established techniques for producing liquid silicone rubber (LSR), the application of silicone in 3D printing for manufacturing purposes is a relatively recent advancement that this research aims to improve. This dissertation explores an innovative design process using transdisciplinary integrated design tools for the development of a 3D Silicone Printing machine capable of fabricating complex geometries such as the aortic heart valve using UV-cured silicone. This research investigates the mechanical properties of UV-cured silicone using tensile testing at different curing rates. The print quality of the 3D-printed silicone aortic heart valves was analyzed using analysis of variance (ANOVA). Additionally, this research aims to produce a 3D-printed silicone aortic heart valve and evaluate the feasibility of the final product. A two-level ANOVA experimental design was used to investigate the impacts of print speed, nozzle temperature, and layer height on the print quality of the aortic heart valve. The findings demonstrated that the UV-cured silicone in the 3D-printed heart valve functioned efficiently, achieving the target flow rates of 5 L/min and 7 L/min. Two distinct leaflet thicknesses (LT) of the heart valve, namely 0.8 mm and 1.6 mm, were also analyzed to simulate calcium deposition on the leaflets. This research contributes to advancements in additive manufacturing technology and the Advanced Cardiovascular Research.