Introduction to High-Resolution Manufacturing from 2D to 3D/4D Printing Technology Evolutions and Design Considerations

Additive manufacturing (AM) includes a wide range of technologies that have been specialized to speed up the prototyping, especially in the field of mechanical engineering. In the last years, the use of polymer composites has opened novel opportunities in terms of functionalities to pave the way for a new generation of prototyping. Applications in electronics, medicine, and energy storage are growing and the prototyping of the devices in these fields faces new challenges related to their complexity and functionalities. In parallel, specific resolution capabilities to prototype high-performing devices are needed. For a better understanding of the potentiality and the differences between AM and other manufacturing approaches, a step inside the fundamental principles should be done. One of the main points is the shift from the top-down approach typical of the industry, as, for example, in microelectronics, to a bottom-up approach, which is typical of additive manufacturing and 3D printing. The paradigm change involves first of all the design. The main outcome of the industrial top-down approach is in fact a process flow, while in the AM bottom-up approach, the main outcome is a virtual model. In this scenario, it is of great interest to understand the new approaches introduced not only for the design of the devices, but also the main concepts related to the printability of 3D models and to the post-processing of the final 3D printed object.