Researchers from the University of Michigan have created self-erasing memories that can be used to stop counterfeit electronics or alert people to goods being transferred in transit. The new material used in the chip temporarily stores energy and changes the color of the light it emits. After a few days, the memory is self-desorbed and can be erased with a beam of blue light whenever needed.
Parag Diotare, a researcher on the project, said it was challenging to detect whether devices had been tampered with because they worked properly but could send information to third parties. If someone turns on the device to install a listening device or other item, the owner can be notified by a self-cleaning barcode printed on the device’s internal chip. Similar barcodes can be placed on an integrated circuit chip or circuit board to prove that the device has not been opened or replaced with internal components.
Barcodes can be written to a device as a hardware simulation of a software authorization key. The scientists created the self-erasing chip using three atomic-thick semiconductor layers superimposed on a molecular film based on anitrobenzene. Anitrobenzene is a molecule that shrinks under ultraviolet light.
This contraction causes the molecule to affect the semiconductor, causing it to emit light at a slightly longer wavelength. To read the information printed on the chip, someone needs to observe it with the right light. One of the researchers involved in the project was interested in the breakthrough because it could be used as a self-wiping invisible ink to send secret messages.
Stretched anitrobenzene naturally releases its stored energy in the dark for about a week, and exposure to heat or light can shorten the time. This time span can be extended if stored in a cold, dark place.