University of Michigan researchers create self-erasing memory

Researchers from the University of Michigan have created self-erasing memory that could be used to stop counterfeit electronics or deliver alerts for shipments tampered with in transit. The chips rely on any new material that can temporarily store energy and change the color of the light it emits. In days, the memory self-erases and could be erased on demand using a flash of blue light.

Parag Deotare, a researcher on the project, points out that it's challenging to detect if a device has been tampered with because it could operate normally but may be sending information to a third party. The owner would be able to get a notification if someone had opened the device to install a listening device or other object using a self-erasing barcode printed on the chip inside the device. A similar barcode could be placed on an integrated circuit chip or a circuit board to prove the device hadn't been opened or had internal components replaced.

Barcodes could be written into devices as a sort of hardware analog of a software authorization key. Scientists created the self-erasing chips from a three-atom-thick layer of semiconductor overlaid on a film of molecules based on azobenzenes. An azobenzene is a type of molecule that shrinks in reaction to UV light.

The shrinkage would cause molecules to tug on the semiconductor, which would, in turn, cause it to emit slightly longer wavelengths of light. To read the message printed on the chip would require someone to look at it with the right kind of light. One of the researchers involved in the project is interested in the breakthrough for its application as self-erasing invisible ink for sending secret messages.

The stretched azobenzene can naturally release its stored energy over about a week in the dark, and the time could be shortened by exposure to heat or light. If stored in a cold, dark place, that time span could be lengthened. When er