Complexity for Free
Perhaps the most dramatic impact of 3D printing is the ability to manufacture objects without factoring their complexity. Fabricating a solid block costs almost the same as fabricating an oddly shaped object with curved surfaces and notches. In either case, the printer will still scan back and forth, depositing one layer at a time, and only the material deposition pattern will change. In the same way that printing a picture of a circle takes no longer than printing a picture of the map of the world, printing a mousetrap does not take more time, resources, or skill than printing a paperweight. Regardless of how you want to measure cost—in production time, material weight, energy waste, or in production planning effort—adding more features hardly changes the cost. In some cases, added complexity can even reduce cost; printing a block with a hole is cheaper and faster than a solid block without a hole. The marginal cost of added complexity is therefore near zero, in stark contrast with conventional manufacturing where every new feature—every additional hole, surface, protrusion, and corner—takes more planning effort, requires longer production time, and consumes more energy and possibly more raw material.
Why do we care about the marginal cost of complexity? It is easy to understand that lowering the cost of manufacturing complex products is a good thing, but the reason is more profound. Industrial revolutions are triggered when a fundamental cost associated with production drops dramatically, essentially taking that factor out of the equation. The industrial revolution of the 19th century occurred when the cost of power dramatically declined, as steam engines replaced horses and waterwheels. As a consequence, these power sources were not only replaced, but the range and types of work that machines could perform greatly expanded, leading to a cascade of innovation, such as railroads and factory automation. The Internet similarly reduced the cost of disseminating information and, as a consequence, expanded the range and types of media that could be distributed—not just online newspapers, but also Wikipedia, blogs, and user-generated content. One could argue that 3D printing has drastically reduced the cost of making complexity. Initially, this simply implies that this technology will gradually replace the old way of making the things we once made in more expensive ways. But in the longer term, the range and types of objects being manufactured will greatly expand.
The Personalization of Manufacturing
Alongside the vast new design possibilities, however, is the personalization of manufacturing. This trend has profound economic implication on how we will design and consume products in the future, who designs them, and where they are made (Lipson and Kurman, 2010). Most important, the ability of anyone to design and make complex products without the barriers of resources and skills of traditional manufacturing will democratize innovation and unleash the long