Although wireless ID tags are becoming increasingly popular for authenticating assets as they change hands, these tags come with various size, cost, energy, and security trade-offs that limit their potential. Popular radio-frequency identification (RFID) tags are too large to fit on tiny objects such as medical and industrial components, automotive parts, or silicon chips. Some tags are built with encryption schemes to protect against cloning and ward off hackers, but they’re large and power hungry. Shrinking the tags means giving up both the antenna package (required for radio-frequency communication) and the ability to run strong encryption, the researchers note, offering to circumvent all these trade-offs with a millimetre-sized ID chip.
Presented at the IEEE International Solid-State Circuits Conference (ISSCC), the tiny chip runs on relatively low levels of power supplied by integrated photovoltaic diodes. It also transmits data at far ranges, using a power-free “backscatter” technique that operates at a frequency hundreds of times higher than RFIDs. Algorithm optimization techniques also enable the chip to run a popular cryptography scheme that guarantees secure communications using extremely low energy.
“We call it the ‘tag of everything.’ And everything should mean everything,” says co-author Ruonan Han, an associate professor in the Department of Electrical Engineering and Computer Science and head of the Terahertz Integrated Electronics Group in the Microsystems Technology Laboratories (MTL).
“If I want to track the logistics of, say, a single bolt or tooth implant or silicon chip, current RFID tags don’t enable that. We built a low-cost, tiny chip without packaging, batteries, or other external components, that stores and transmits sensitive data.”