Abstract: In vitro constructing of a personalized auricle cartilage scaffold with lifelike appearance and adjustable mechanical strength, is an important method in tissue engineering to repair the auricle defect. Aiming at this, the melted extrusion forming technique based on the rapid prototyping principle is adopted, particle polyurethane biomaterial is used, and an experiment platform is built up. Then a series of experiments are carried out to study the effects of technical factors on forming process and scaffold mechanical properties, in order to find out the best parameter range for manufacturing the auricle cartilage scaffold. It is found that nozzle temperature has an impact on extrusion stability and material flexibility; forming room temperature affects the structure uniformity and interlayer integrity; feed speed and scanning speed should match extrusion speed, to maintain the strand uniformity and the forming stability; nozzle scanning with different speeds results in different temperature fields, which also affects the flexibility of formed structure; there exists a minimum local forming; temperature and the discrete processing parameters of CLI mathematical model affect the mechanical properties of the formed scaffold. Therefore, based on the melted extrusion forming technique, suitable polyurethane auricle cartilage scaffold can be constructed to fulfill the personalized demand of different patients, not only with exact lifelike appearance, but also with proper mechanical properties close to the natural auricle cartilage.

Key words: Auricle cartilage, Melted extrusion forming, Polyurethane, Rapid prototyping, Scaffold, Axiomatic design, Entropy, Safety, Trans-scale correlation, High speed milling cutter