Breathing on this chip reveals a secret message

The hidden image only becomes visible when humidity levels surpass 60 percent. More information Adding us as a Preferred Source in Google by using this link indicates that you would like to see more of our content in Google News results. The encoder could also be used to reveal a security code on a credit card. 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 .