The world's smallest and thinnest RFID tags were introduced this year by Hitachi. Tiny miracles of miniaturization, these RFID chips (Radio Frequency IDentification chips) measure just 0.05 x 0.05 millimeters.
The previous record-holder, the Hitachi mu-chip, is just 0.4 x 0.4 millimeters. Take a look at the size of the mu-chip RFID tag on a human fingertip.
Now, compare that with the new RFID tags. The "powder type" tags are some sixty times smaller.
The new RFID chips have a 128-bit ROM for storing a unique 38 digit number, like their predecessor. Hitachi used semiconductor miniaturization technology and electron beams to write data on the chip substrates to achieve the new, smaller size.
Hitachi's mu-chips are already in production; they were used to prevent ticket forgery at last year's Aichi international technology exposition. RFID 'powder,' on the other hand, is so much smaller that it can easily be incorporated into thin paper, like that used in paper currency and gift certificates.
But Kodak has gone one step further and has recently patented digestible tags that are harmless and intentionally fragile.
The tags would be covered with soft gelatin that takes a while to dissolve in the stomach. After swallowing a tag a patient need only sit next to a radio source and receiver. They stop working when exposed to gastric acid for a specific period of time, providing a subtle way to monitor a patient's digestive tract.
Kodak says that similar radio tags could also be embedded in an artificial knee or hip joint in such a way that they disintegrate as the joint does, warning of the need for more surgery
