Self-erasing chips, developed at the University of Michigan, can help stop counterfeiting electronics or warn against opening sensitive shipments. Details and new developments are published by Advanced Optical Materials magazine.
Chips that erase data on their own use a new material. They temporarily store energy by changing the color of the emitted light. Data is self-erased in a matter of days, and the chip can also be erased on request with a blue flash.
“It is very difficult to determine if a device has been compromised. It can work fine, but it does more than it should by sending information to a third party, ”explains Parag Deotar, assistant professor of electrical engineering and computer science at the University of Michigan.
With a self-destructing barcode printed on a chip inside the device, the wearer is prompted if the mechanism has been tampered with to secretly install a listening device. Or, the barcode can be written and placed on integrated circuits or printed circuit boards. This will help prove that they were not opened or replaced during transport.
Self-erasing chips are built from a layer of semiconductor three atoms thick on top of a thin film of molecules based on azobenzenes – the type of molecules that shrink in response to ultraviolet light. These, in turn, attract the semiconductor, causing it to emit light at a slightly longer wavelength.
Expanded azobenzene naturally loses stored energy over about seven days in the dark – a time that can be shortened by exposure to heat and light or increased by storage in a cool, dark place. Anything written on the chip, be it an authentication barcode or a secret message, will disappear when the azobenzene stops stretching the semiconductor. Alternatively, it can be erased immediately using a flash of blue light. After erasing, the chip can write a new message or barcode.
The next steps in the research include increasing the amount of time the material can keep the information intact, which will help the new design fight counterfeiting.