Ina Sava Gallis shows a sample of an optical tag with the Sandia logo under an ultra violet light. (Photo by Craig Fritz) A high-tech invisible ink invented at Sandia National Laboratories could ...

A gold compound shifts from a visible fluorescence to emitting infrared when ground -- a big shift with potential applications in bioimaging and security inks. A gold compound shifts from a visible ...

It's the invisible ink of childhood, all grown up and with a serious purpose. Researchers have developed a high-tech ink, which they used to print QR (quick response) codes that are invisible in ...

A world where documents talk, objects carry secrets, and your veins guide medical tools may be closer than it seems. A team of researchers from Universidad Carlos III de Madrid (UC3M), the ...

QR codes, those goofy black-and-white arrangements of digital information, could help secure bank notes. Scientists just showed that they could print an invisible QR code made of a high-tech ink ...

A gold compound shifts from a visible fluorescence to emitting infrared when ground - a big shift with potential applications in bioimaging and security inks. Some materials luminesce, changing their ...