There has been a long tradition in the scientific community to celebrate the approach of Christmas and New Year by creating miniature miracles of the respective theme. Thanks to this, we have already seen the smallest New Year’s card, the figure of a tiny snowman, and last year scientists from the Technical University of Denmark (DTU) demonstrated the pre-holiday mood with the help of “the thinnest Christmas tree”. made of graphene. That same year, scientists from DTU created the “world’s smallest audio recording,” something akin to a classic vinyl record on which some of the famous Christmas tune is engraved.

At just 40 microns (thousandths of a millimeter) in diameter, this polymer-based disc has all the essentials – a tag in the middle and a concentric spiral soundtrack featuring the first 25 seconds of the song “Rockin’ Around the Christmas Tree”. As the name suggests, it was made using a commercial device called the NanoFrazor, a nano-grinding machine that can separate a very small amount of material from a solid piece and give it a specific shape.

NanoFrazor’s high-resolution image not only showed the label in the middle of the disc, it also allowed stereo audio to be encoded in a single track with track width changes including left channel audio and track depth changes including right channel audio. Of course, the sound from such a small disc cannot be reproduced using a regular player. Only the NanoFrazor instrument itself or the more expensive scanning atomic force microscope with a tip sharpened to one atom thickness can do this.

Naturally, the creation of a tiny audio disc has no practical value. But all this demonstrates the impressive capabilities of the NanoFrazor device, which can quickly and qualitatively form various nanostructures with the highest precision.

“First of all, we plan to develop and manufacture new miniature magnetic sensors that can detect electrical currents flowing in the brains of living things,” the researchers from DTU write. “We also plan to use NanoFrazor to create nanostructured surfaces, with the help of which we can better control the propagation of electronic waves and that we can control”.