UC San Diego unveils postage stamp chip revealing hidden images
A team at UC San Diego has come up with a postage-stamp-sized chip that can show hidden images or text when you breathe on it.
The magic happens thanks to humidity—your breath decides which layer of information gets revealed.
It's a cool way to store secret data, and the study was published in May 2026.
Cheap hydrogels enable fast resettable data
The chip uses affordable materials like hydrogels and antimony trisulfide, so it's easy to make and reuse.
When humidity changes, a gap between two layers shifts, letting light reveal the hidden information in under one-half second.
You can reset the top layer with ultraviolet light or re-encode the bottom with lasers.
first author Asad Nauman says this technology could help keep credit cards secure or monitor environmental changes, all without breaking the bank.