3D printing, also known as additive manufacturing, has recently played an important role in the production of large & complex components recently. Earlier this year, we discussed how 3D printing was used to build the world’s largest printed neighborhood, consisting of 100 3D printed houses, and how the technique was used to print a school in Africa in just 18hrs.
Now, a group of scientists have set a new benchmark in 3D printing.
In an article published in the scientific journal Nano Letters, Dr Dmitry Momotenko, a chemist from the University of Oldenburg, as well as a team of researchers from ETH Zurich, Switzerland, & Nanyang Technological University, have succeeded in making ultra-small metal objects. using the new technique..
According to the team, their modus operandi can be used to craft copper objects as small as 25 billionths of a meter in diameter (equivalent to 25 nanometers).
Their electrochemical 3D printing technique manufactures complex conductive structures with nanometric resolution and could have potential applications in battery technology, microelectronics, & sensor technology.
Go small or go home
The latest 3D printing technique revolves around the familiar electroplating process. Momotenko’s nano-printing method requires a solution of positively charged copper ions in a tiny pipette.
Liquid escapes from the pipette tip through a printing nozzle. In the experiments carried out, the nozzle opening had a diameter of between 253 & 1.6 nanometers. Only 2 copper ions can pass through such a small opening at the same time.
The team then developed a technique to monitor the printing process. They recorded the electric current between negatively charged substrate electrode & a positive electrode inside the pipette. In an automated process, the nozzle approached the negative electrode for a very short time & then re-tracted as soon as metal layer had exceeded a certain thickness.
Using this technique, the researchers gradually applied consecutive layers of copper to the surface of the electrode. The precise positioning of nozzle allows them to print vertical columns & spiral nano structures. They could also produce horizontal structures by changing printing direction.
According to the team, the smallest objects that can be printed with this method are around 25 nanometers in diameter, which is equivalent to 195 copper atoms in a row.
The new electrochemical technique could be used to print much smaller metallic objects that have never been printed before. The smallest objects that can be produced with this method are 4000 times larger than those in this study.
“The technology we are working on combines both worlds: metal printing & nano-scale precision,” Momotenko told Phys.org. “3D printed catalysts with a high surface & special geometry to allow special reactivity could be prepared for production of complex chemicals,” he said.
Momotenko & his team are currently working to improve the efficiency of electrical energy storage using 3D electrodes. To speed up the charging process, their NANO3DLION project focuses on significantly increasing the surface area of the electrodes & reducing the distances between cathode & anode in lithium-ion batteries via 3D printing.