3D Printing for Security Labels

Texas A&M University researchers aren’t the only ones looking into additive printing to address the issue of counterfeiting.

A research team at Hong Kong University (HKU) is working on the development of an extremely precise 3D printing process that can be used to produce polarisation-encoded anti-counterfeiting labels.

It is not only the fact that the dimension of a 3D versus a 2D label is different, but also the digital information included with it. In their research, published in a paper titled ‘Three-Dimensional Printing of Dipeptides with Spatioselective Programming of Crystallinity for Multilevel Anticounterfeiting’, the team used diphenylalanine (FF) as a material, allowing them to 3D print dipeptides.

Dipeptides are chemical compounds consisting of two amino acid residues. The researchers at HKU chose to develop these because of their unique properties, noting in particular their piezolectricity and optical birefringence due to their crystalline nature.

In the paper, Dr Ji Tae Kim, the leader of the research team, explains the procedure of the new 3D printing method in detail.

‘Our new 3D printing method combined with nature-driven molecular self-assembly can print multi-segmented 3D FF micro- pixels with programmed crystallinity for high-density data encryption’, he wrote. ‘By utilising different responses of the amorphous and crystalline segments to polarised light, a tiny single 3D pixel can encrypt a multi-digit binary code consisting of ‘0’ and ‘1’. The information capacity can be increased to 211 with a single eleventh- segmented freestanding pixel on a tiny 4 µm2 area, which is 1,000 times smaller than a hair strand.’

The team is confident that this 3D printing process can greatly enhance security and prevention of counterfeiting in the future, allowing security labels to be customised and produced anywhere and at any time.

The full article can be found at https://pubs.acs.org/doi/abs/10.1021/acs.nanolett.2c01761.