Quantum dot firm UbiQD bags US anti-counterfeit patent

US start-up UbiQD has been awarded a US patent on the use of its quantum dot technology in anti-counterfeit inks.

Quantum dots - also known as colloidal semiconductor nanocrystals - have 'tunable' optical properties such as photoluminescence and are already finding commercial applications in device such as ultra-high density televisions. Their ability to emit different wavelengths of light means they have been pitched as an alternative to dyes and pigments for security inks.

The Los Alamos, New Mexico-based quantum dot specialist says its quantum dots have low-toxicity compared to rival technologies, inexpensive and compatible with low-cost liquid manufacturing techniques.

The abstract of the patent - awarded on July 5 - appears below.

Quantum dot security inks

Abstract: A security ink is provided which includes a liquid medium having a plurality of quantum dots disposed therein. Upon excitation with a suitable light source, the ink exhibits a quantum yield greater than 30 per cent, and a photoluminescence which has a lifetime of more than 40 nanoseconds and which varies by at least 5 per cent across the emission spectrum of the quantum dots. Also disclosed are apparatuses for using the same for anti-counterfeit or authentication purposes, which uniquely identifying the presence of photoluminescent materials by spectrally resolving their photoluminescence lifetime.

US Patent No. 9,382,432