The tiny chips are smaller than salt grains and integrate several hundred thousand transistors. Computing power for each chip is estimated to be similar to an early 1990s high-end x86 CPU. They will be used as "cryptographic anchors" in mass produced goods, as a blockchain-enabled anti-counterfeit measure.
https://www.notebookcheck.net/IBM-shrinks-computer-size-to-1-square-millimeter.289916.0.html