Ethical Issues of 4D Printed Medical Devices.

Since the dawn of additive manufacturing technologies in the 1980s and 90s, now commonly named 3D printing, the possibility of processing raw materials into freeform designed objects with unprecedented shape complexity opened new avenues for the development of medical devices. Indeed, the geometries of nature and the human body are extremely multifaceted, with even fractal- like or multiscale levels of detail, counting with functional gradients of properties, including topology and topography optimizations, to cite some interesting features. In consequence, classical subtracting manufacturing technologies, shape forming tools, and mass production chains are suboptimal for personalizing medical devices and adequately emulating life.