Popular science reports on an advancement by Hitachi that’s created RFID chips smaller than the width of a hair.
“The diamond ring of the future will radiate its unique beauty—quite literally—thanks to a minuscule radio-frequency identification (RFID) chip embedded in it. Scientists at Hitachi Research Labs in Japan have devised the smallest RFID tag ever, just 0.05 millimeter by 0.05 millimeter, tinier than a grain of sand.”