A potential game changer in the 3D printing space is Rapid Liquid Printing or (RLP). Why is it exciting? Normal 3D printers have to build from the ground up, one layer at a time. It wastes a lot of energy and time because the print head paths are restricted to one plane. In RLP, by contrast, prints are made in a bath of gelatin, the printer head is freely able to move in 3 dimensions allowing it to take the most direct path to form prints. No wasted movement = less time and more structurally sound parts.

RLP was developed by MIT a few years back and I haven't heard much from it since. Maybe that will change over the next few years. https://selfassemblylab.mit.edu/rapid-liquid-printing