Two-dimensional nanomaterial offers promise for high-efficiency batteries and electromagnetic shielding.
As 3D printing technology has continued to mature over the last few decades, news about novel materials being 3D printed has become less frequent. The abundance of material options now available for additive manufacturing (AM) is certainly a good thing, but it does make such stories less remarkable than they used to be.
However, a team of materials scientists and engineers at the Korea Electrotechnology Research Institute (KERI) has just announced a breakthrough that’s definitely worth talking about. Led by Seol Seung-kwon, a professor and principal scientist at KERI, the team has developed the world’s first technology for 3D printing microstructures from MXenes, two-dimensional inorganic compounds consisting of atomically thin layers of transition metal carbides, nitrides or carbonitrides.
While there has been considerable interest in MXenes for battery and electromagnetic shield applications since their discovery in 2011, being able to 3D print using MXene ink has been out of reach, due to challenges in viscosity and concentration: too much and the pipette nozzle would clog, too little and the desirable material properties wouldn’t be borne out in the 3D printed structures.
To solve these problems, the team developed a ‘Meniscus’ method, based on the so-called Cheerios effect, which occurs when a droplet is gently pressed or pulled with a constant pressure, causing it to form a curved surface on the outer wall without bursting due to capillary action. Exploiting this effect, the KERI researchers developed a 3D printing nano ink by dispersing highly hydrophilic MXene in water without the use of a binder, enabling the printing of high-resolution microstructures even with low viscosity.
According to the researchers, this resulted in a printing resolution 270 times higher than existing technologies, at 1.3 µm.
“We put a lot of effort into optimizing the concentration conditions of MXene ink and precisely analyzing the various parameters that could arise during the printing process,” said Seung-kwon in a press release. “Our technology is the world’s first achievement that allows the creation of high-strength, high-precision 3D microstructures by leveraging the advantages of MXene without the need for any additives or post-processing.”
The hope is that 3D printed MXene structures cam increase the surface aera and integration density of battery and energy storage devices, maximizing ion transfer efficiency and boosting energy density. For electromagnetic shielding, 3D printed MXene can potentially amplify internal multiple reflections and absorption effects.
The research is published in the journal Small.
