Somark Innovations, a small company working out of Saint Louis, has successfully tested an RFID tattoo, on cows, mice and rats: enabling an identifying number embedded under the skin to be read from over a meter away.
Implanting identification numbers into animals is nothing new: in the UK pets travelling abroad, and returning, must have an identification chip inside them, but these are expensive and relatively large (12mm by 2mm in diameter), and the readers have a very restricted range.
The system developed by Somark uses an array of needles to quickly inject a pattern of dots into each animal, with the pattern changing for each injection. This pattern can then be read from over a meter away using a proprietary reader operating at high frequency.
Traditional radio frequency identification (RFID) technologies use tags stapled to the ears of animals, but these are much more expensive and have a habit of tearing out too, which is unpleasant for the animal as well as inconvenient for the farmer. The systems currently used for pets are internal, so can't tear out, but are much more expensive again.
Somark are in the process of raising money to exploit the technology, and point out that what works for animals can, of course, also work for people; identifying Military Personnel as one of their secondary markets, after cattle and other livestock.