Self-Erasing Memory Chip, Read and Written with Light, Could Secure Future Devices
Inspired by graphene, the three-atom-thick material which powers the chip can be written and erased using light — and self-erases over time.
Researchers at the University of Michigan have developed a self-erasing security chip, designed to detect if a device has been tampered with in-transit or to out counterfeit or maliciously-cloned products.
"It's very hard to detect whether a device has been tampered with," explains Assistant Professor Parag Deotare, of his team's research. "It may operate normally, but it may be doing more than it should, sending information to a third party."
The solution: A security chip built from a novel azobenzene material just three atoms thick which temporarily stores energy, changing the colour of the light it emits. The message encoded in the chip can only be read using a particular wavelength of light — or can be erased using a flash of blue light. If it's not manually erased, the contents of the chip self-erases in a matter of days — longer if stored in a cold, dark place, or shorter if exposed to heat and light.
The material itself is manufactured in a surprisingly low-tech way, inspired by a graphene: A layer of the molecules are floated on water and a silicon wafer dipped to coat it; then Scotch tape is applied to a chunk of tungsten diselenide to pull off single layers, which are then applied to the azobenzene-coated chip with a stamp.
There's work still to be done before the chips, which can be rewritten once erased, can protect commercial devices, however: The team has only been successful in storing the written data for seven days, and is currently looking into ways to extend its lifespan ahead of commercialisation of the technology.
The team's work has been published under closed-access terms in the journal Advanced Optical Materials.