UMD Researchers’ Novel Reactive Ink Prints as Everlasting Copper

A new invention from a team that includes a University of Maryland researcher halts the copper degradation cycle that turns statues, roofs and even nickels green.

Researchers have developed a liquid reactive ink that can print copper onto nearly any surface without oxidation or corrosion. Shenqiang Ren, a professor in the Department of Materials Science and Engineering, along with Professor Liangbing Hu from Yale University and Senior Scientist Haimei Zheng from the Lawrence Berkeley National Laboratory in California, led a collaborative effort that spanned over a decade of discovery. The results of this work were published May 14 in the journal Science as the cover article.

Copper is a hidden backbone of modern life, carrying electricity in AI systems, data centers, wireless networks, circuit boards, solar panels and batteries. Given its applicability across industries, the reactive ink could broadly lower costs.

“These printed copper traces act as the ‘wiring’ inside next-generation electronics, produced faster, cheaper and with less waste,” said Ren.

Using a versatile blue ink, the team created a fast, relatively low-temperature method at 150 degrees Celsius to create copper that remains stable over time. This breakthrough addresses two long-standing challenges in the field: developing printable copper inks under ambient conditions and preventing it from corrosion and oxidation.

To demonstrate the technique’s versatility, the researchers printed copper conductor traces for solar cells, circuit boards, small-scale replicas of the Testudo statue and even models of the Eiffel Tower. Additional testing showed the material’s ability to remain intact after six months of seawater submersion.

This new approach could replace conventional copper processing methods such as plating and chemical etching, reducing time, cost and environmental impact.

“The newly developed ink has the potential to revolutionize the conductive ink industry by enabling the use of copper instead of more expensive metals, such as silver, across electronic, energy and environmental applications,” said Hu, who collaborated on this study while a UMD faculty member. 

He and Ren have cofounded the startup NewCopper to commercialize the ink.