Quantum dots (QD) are one of the most intriguing technologies we see today. They are found most notably in TVs and displays, but are also being used in horticulture. The advantages of the technology, particularly the ability to tune the quantum dots to practically any color, offer the potential for new applications, such as security inks.

SICPA is the leading manufacturer of security inks in the world, with estimates placing SICPA’s security solutions appearing in up to 90% of the world’s currency, stamps and security documents such as passports. The company is also heavily involved in brand security, leveraging its experience to help combat counterfeiting.

For the past six years, SICPA has been partnering with UbiQD, a New Mexico-based nanotechnology company specializing in quantum dots, on a variety of security applications. The two companies recently announced a new line of security inks utilizing quantum dots that sounds promising.

“This partnership with UbiQD has enabled us to develop cutting-edge optical and machine-readable features that we will be able to add to our robust portfolio of security inks and solutions for our clients,” said Scott Haubrich, R&D director for SICPA US.

Because of the wide range of tunable colors, security features based on quantum dots are very difficult to reproduce. Haubrich said that using quantum dots can make counterfeiting extremely difficult.

“The goal with any security ink is to impart unique optical features that are difficult to mimic by counterfeiters,” Haubrich noted. “In general, quantum dots can be used to create unique optical properties owing to their continuously adjustable optical qualities.”

“At UbiQD, our core quantum dot technology is particularly unique in that no other known fluorescent materials can mimic them,” added Hunter McDaniel, founder and CEO of UbiQD, Inc. “Additionally, our dots are composed of safer compounds than traditional dots.”
 

What are Quantum Dots

Essentially, quantum dots are highly fluorescent nanomaterials that can have any color that is needed.

“The colors of light that these nanocrystals absorb and emit is determined by their size, which we control in the manufacturing process,” McDaniel noted. “The key advantages of dots versus dyes or phosphors are their solution processability owing to their small size, extremely high brightness, tunable and pure colors, low-costs, and long-term durability.”

How then do quantum dots fit with security inks? Haubrich said that the ability to access a broad range of colors is a key feature.

“With dyes and phosphors, a given compound has a fixed absorption and emission spectrum, so to create a new color, you’d need a completely new compound,” Haubrich pointed out. “There are a finite number of colors that you can access because there are only so many compounds available. Whereas with quantum dots, you can use the same composition of matter to create almost any arbitrary color. It’s a paradigm shift for security inks.”

McDaniel noted that UbiQD and SICPA started talking in 2016, and began collaborative research and development in 2017. UbiQD and SICPA are now expanding their partnership to commercialize several security applications based on the novel characteristics of UbiQD’s technology.

“We’ve been going strong ever since then, having completed a number of R&D milestones,” added McDaniel. “Due to the confidential nature of this work, we haven’t been able to say anything publicly about our partnership until now with the signing of this exclusive supply and licensing agreement.”

There are always challenges with using new technologies, and quantum dot-based inks are no exception. McDaniel pointed to reliability and consistency are areas that the partners have been able to overcome.

“Some security features need to perform under harsh conditions for years,” McDaniel added. “The tunability of quantum dots is a key feature, but can also be a challenge because minute differences in size between batches can lead to color differences. At the nanometer size regime, even a difference of a single layer of atoms in each nanocrystal can throw off the ensemble optical properties.”

McDaniel sees tremendous opportunities ahead for this collaboration.

“With SICPA’s domain expertise and leadership position in security markets, and its proprietary sensor and ink technologies, UbiQD has an ideal partner to commercialize our quantum dot technology for anti-counterfeiting, brand protection, supply chain integrity, and more,” McDaniel concluded.