Scientists are working on an easier way to detect counterfeit money—and they have beetles to thank for it. The system, which would allow people to reveal counterfeit cash by breathing on it, is based on the ability of a longhorn beetle species to change color based on local humidity, Chemistry World reports. Researchers in China are working on an inexpensive inkjet printing technology that works similarly; the ink adsorbs nearby vapors, including those in our breath, and changes color in response. "It is particularly refreshing to see simple techniques such as inkjet printing being used to such great effect," says an outside expert.
Comparable research appeared a few months ago, when scientists in Michigan and South Korea revealed a film which, when touched by breath, reveals images or words. That technology could be used to fight the creation of items like fake passports, Wired reported; blowing on the passport could make a special logo appear, for instance. While it's expensive and difficult to create the equipment behind the film—perhaps deterring counterfeiters—it's cheap to produce the stuff once the gear is up and running, Gizmodo reported. (Perhaps that could help stop the likes of this counterfeiting mom.)