3D printing is also called additive manufacturing and it has massively transformed several industries.
A paper was published in the journal Nano Letters where Dr. Dmitry Momotenko, a chemist at the University of Oldenburg, along with a team of researchers from ETH Zurich, Switzerland, and Nanyang Technological University, told that they have succeeded in fabricating ultrasmall metal objects using the new technique of 3D printing.
The team’s modus operandi can be used to make objects out of copper just 25 billionths of a meter in diameter (equivalent to 25 nanometers).
Their electrochemical 3D printing technique fabricates complex conductive structures with nanometer resolution. It can have innovative applications in battery technology, microelectronics, and sensor technology.
This is related to the process of electroplating. Momotenko’s nano printing method requires a solution of positively charged copper ions in a tiny pipette. The liquid emerges from the tip of the pipette through a print nozzle. In the experiments conducted, the nozzle opening had a diameter of between 253 and 1.6 nanometers. Only two copper ions can pass through such a tiny opening at the same time.
Afterward, to monitor the printing process, they recorded the electrical current between the negatively charged substrate electrode and a positive electrode inside the pipette. In an automated process, the nozzle approached the negative electrode for a very short time and then retracted as soon as the metal layer had exceeded a certain thickness.
The scientists slowly applied consecutive copper layers to the electrode’s surface. The precise positioning of the nozzle lets them print vertical columns and spiral nanostructures. Horizontal structures could also be produced by changing the printing direction.
The smallest objects that are possible to be printed through this method have a diameter of 25 nanometers, which is equivalent to 195 copper atoms in a row.
“The technology we are working on combines both worlds — metal printing and nanoscale precision,” Momotenko told Phys.org. “3D-printed catalysts with high surface area and special geometry to allow particular reactivity could be prepared for the production of complex chemicals,” he said.
Momotenko and his team are currently working towards improving the efficiency of electrical energy storage through three-dimensional electrodes. Their NANO-3D-LION project will focus majorly on increasing the surface area of electrodes and reducing distances between the cathode and the anode in lithium-ion batteries through 3D printing. This will ensure faster charging.
