4D printed smart nitinol based medical devices Additive manufacturing (AM) technologies have reinvented many areas of product development. In the medical field, the ability to promote patient personalization has become a key factor. AM technologies allow the manufacturing, based on medical images, of models for surgical planning, surgical guides and even, implants and porous scaffolds for tissue regeneration. However, many of these applications are static and do not allow a dynamic interaction, which would enable minimally invasive surgeries. or allow shape changes according to the healing process of the tissue. The use of "smart" medical devices, obtained through the emerging concept of "4D printing", capable of undergoing progressive metamorphosis according to surgical procedures, biological integration and/or healing processes, is still a dream, especially in metallic materials that offer substantial load bearing capabilities. The AM of smart metallic alloys, like nitinol, might offer solutions in this area.