Above: A diamond is micromarked with an image of a dog.

With micromarking lasers and taggants, one company tailors bespoke QC solutions

June 2013 - Because chemists can’t detect molecules with their naked eyes, they’ve developed tools that can see for them. The obvious one here is the microscope, but a lens alone doesn’t verify that what is being observed is actually what it is. This is where Microtrace LLC comes in.

The company, based in Minneapolis, develops security solutions on hard-to-mark objects with three methods: taggants, lasers and security labels. Taggants are uniquely encoded materials or chemistries (like virtual fingerprints) that, when added to a material or solution, can be detected and quantified for brand protection with a handheld device. Say you’re installing prepainted steel panels. You want to ensure the metal coating is the same brand as chosen for performance reasons by the project manager. By scanning the panels with a hand-held reader, the taggants in the paint will tell you, within a margin of error, if it’s the real thing or if the product has been diluted. This protects brands from false warranty claims and liability issues that arise from a counterfeit substitution product or dilution of genuine product.

“Microtrace taggants are used for yes/no identification and can also be quantified to identify mix ratios of materials,” says Brian Brogger, vice president of Microtrace. Then, when the product is applied, or in analysis of the finished product, the brand owner can test the substrate to verify it is, in fact, their genuine material and that it’s been applied at the correct loading level. “We can tell if it’s been diluted. For most applications, we can get down to a 10 percent dilution. Five percent is within margin of error.”

3M originally developed taggant technology in the 1970s for the post-detonation tracing of explosives. Since then, Microtrace has developed the microtaggant technology, as well as invented two new taggant technologies —spectral taggant and molecular taggant. Spectral taggant has been developed exclusively for print applications; molecular taggant for identification of bulk materials. While the Microtrace microtaggant is still used to identify explosives, the main application for the Microtrace taggants is brand protection.

A diluted or compromised product not only shorts brand owners of revenue, but also potentially leads to liability arising from premature material failure. The molecular taggant is also proprietary: it’s undetectable without the Microtrace detector. The taggant is delivered to the customer formulated as a masterbatch or concentrate within a component or raw material of the product to be tagged, according to Microtrace.

Laser security

Micromarking lasers make microscopic markings on items for brand protection. The markings can be anything from 2-D barcodes to human readable serial numbers and logos.  The lasers also can be used for more functional applications such as microdrilling or removal of flashing on molded parts. Microtrace has experience in microfabrication on materials including metal, glass, ceramics and more.

In a verification setting, for example, Microtrace has marked metal medical stents. By marking the stent surface, doctors can match it to the correct patient—a worthy reassurance in a time when medical staff constantly ask patients their birthdays upon entering their rooms.

On a bit of a larger scale, Microtrace can mark logos or text microscopically on metal that, like the taggant, can be read from a device for authentication. For one customer, a manufacturer of big pipes, Microtrace made a small plug for the end of the pipe so it could be tracked. The smallest 2-D barcode Microtrace has made is a 10 by 10 matrix of dots. 

“With spacing, that’s 20 microns squared,” says Brogger. “A human hair is about 100 microns, so we made that about one-fifth the size of a human hair.”

Hardware-wise, laser systems can stand alone or be bolted on manufacturing lines. Microscopes can be used to read the micromarkings. Microtrace designs and manufactures turnkey laser systems optimized for the customer’s application.  The company designs and manufactures several lasers—excimer lasers, CO2 lasers, pico, Nd YAG lasers and fiber optic lasers. With taggants, tools like UV light, laser pens and proprietary detectors read the invisible traces. With honed micro technology, invisible codes aren’t so hard to mark, after all.