The encoder could also be used to reveal a security code on a credit card. Image: NDAO Lab   Get the Popular Science daily newsletter💡 Breakthroughs, discoveries, and DIY tips sent six days a week. By signing up, you confirm you are 16+, will receive newsletters and promotional content and agree to our Terms of Use and acknowledge the data practices in our Privacy Policy . You may unsubscribe at any time. A team of engineers at the University of California San Diego (UCSD) have developed a humidity-based image encoder that looks straight out of James Bond’s Q-Lab . The postage stamp-sized chip can store a hidden message that is only revealed when exterior humidity levels surpass 60 percent. The image can then be concealed again by bringing humidity back down. In practice, that means someone handed an object with the chip on it could simply breathe on it to unveil its secret message.…