Researchers from the University of Maryland, in collaboration with Yale University and the Lawrence Berkeley National Laboratory, have developed a groundbreaking liquid reactive ink that enables the printing of copper on nearly any surface without the risk of oxidation or corrosion. Published on May 14 in the journal Science, this innovation addresses the persistent issue of copper degradation, which affects various applications such as statues, roofs, and electronic components. The team, led by Shenqiang Ren, has created a method that operates at a relatively low temperature of 150 degrees Celsius, allowing for the production of stable copper traces that can serve as 'wiring' in next-generation electronics. This new approach not only demonstrates versatility—having been used to print copper traces for solar cells, circuit boards, and even miniature models of the Eiffel Tower—but also shows resilience, as the material remained intact after being submerged in seawater for six months. By potentially replacing more expensive metals like silver in conductive applications, this reactive ink could lower production costs and environmental impact across various industries. Ren and Hu have founded the startup NewCopper to bring this technology to market.