The Princeton Plasma Physics Laboratory (PPPL) has developed a small, experimental nuclear fusion reactor using 3D-printed and off-the-shelf parts.The reactor, based on a 'stellarator' design, aims to release large amounts of clean energy by fusing atomic nuclei without toxic waste.Princeton's model was built within a year for $640,000, a significant reduction in cost and time compared to traditional fusion reactors.This innovation brings us closer to a zero-carbon, high-energy future and has attracted attention from tech giants like Microsoft, Amazon, and Google.