New 'Invisible' Bar Code to Thwart Criminals

Researchers have developed new 'invisible' bar codes that are nearly impossible for criminals to replicate.

The new system is based on adding certain types of nanoparticles to materials as part of the manufacturing process that can be read later using a special device.

Bar codes are used to track the movement of merchandise and in some cases, to prove that criminals have been counterfeiting products.

However, printed bar codes are relatively easy to reproduce, thus, criminals can make their own.

Researchers at Worcester Polytechnic Institute in Massachusetts have come up with a way to allow for the creation of invisible bar codes that are nearly impossible to replicate.

The idea revolves around several types of metal nanoparticles, each of which has a unique melting point.

Mixing the nanoparticles together allows for creating unique thermal signatures.

To use the nanoparticles, manufacturers would simply add them into the mix when creating metals, papers and even fluids, 'phys.org' reported.

The researchers said the addition of the nanoparticles doesn't change how a material looks, doesn't react with anything in it or impact how a finished product performs.

Reading the new type of "bar code" requires a device capable of performing differential scanning calorimetry (DSC) - a technique based on assessing the difference in the amount of heat required to heat different parts of a sample material.

The researchers said their nanoparticle bar codes could be used with paper, metals, fluids and even drugs.

The research is published in the journal Scientific Reports.